Thèses sur le sujet « Lamb quality »

American lambs are often over-finished and lack consistent quality. It has been suggested that the use of intact ram lambs can decrease USDA YG and improve growth efficiency. However, ram lamb carcasses are underutilized because of potential issues, the most crucial being off-flavor development. Our hypothesis for this study is that U.S. producers can take advantage of intact ram lamb growth and performance with no detriment to product quality, as long as lambs are slaughtered before the attainment of puberty. Three breeds (Hampshire, Dorset, and Columbia), three slaughter weights (light, medium, and heavy) and two sexes (rams and wethers) were evaluated. Results indicate that ram lambs can provide a satisfactory eating experience, however, in one of our studies compounding of maturity and slaughtering intact rams increased incidence of off-flavors. It remains undetermined whether the small differences in sensory characteristics would be detectable by everyday consumers.

Quality is an accumulation of attributes that satisfy customer preferences and expectations. Lamb quality is a moving target that means different things to the supply chain and sheep/lamb industry stakeholders. The objectives of this research were to determine the rank, definition, relative preference, and willingness to pay (WTP) for seven quality attributes and quantify product attributes of lamb at U.S. retail markets. Structured interviews of retail and foodservice respondents were conducted from May 2014 to March 2015 via face-to-face or telephone with lamb/protein purchaser representatives of retail (n = 60), foodservice (n = 45), and purveyor (n = 15) marketing sectors. Shares of preference (relative percentage of preference) in best/worst evaluation for all interviews indicated that eating satisfaction (38.9%) was the most important attribute.

Shares of preference for all seven specified quality attributes were statistically different from each other (P < 0.05). Credence attributes of origin (17.2%) and sheep raising practices (13.6%) ranked second and third overall, respectively. Physical product characteristic traits of product appearance/composition (10.5%) and weight/size (8.5%) were ranked fourth and fifth in shares of preference, respectively. Nutrition/wholesomeness (7.1%) ranked sixth and product convenience/form (4.2%) ranked seventh in the overall ranking across all sectors of retailer, foodservice, and purveyor interview respondents.

In WTP analyses, origin (25.8%) and sheep raising practices (20.0%) had the greatest likelihood of being a non-negotiable requirement for lamb purchasers. Eating satisfaction was the trait most likely to receive a premium (71.7%) from buyers, and product assurance of eating satisfaction generated the greatest average WTP premium (18.6%). This research indicated, across all sectors, eating satisfaction, defined as lamb flavor/taste, was the most important quality trait to those who purchase lamb.

In-store evaluations of retail lamb labels showed that lamb shoulder and loin chops originating from the U.S. garnered the greatest price premiums compared to either New Zealand or Australian lamb (P < 0.05). Lamb was merchandised to American consumers at specialty type stores at an increased price per kg premium than either locally owned or national grocery chains (P < 0.05). Lamb shoulder prices at retail were merchandised with the greatest premium for product of U.S. origin from a specialty store packaged in modified atmosphere packaging and labeled with local (+ $5.42/kg) and natural (+ $5.40/kg) claims (P < 0.05). Lamb loin prices at retail were merchandised with the greatest premium for product of U.S. origin from a specialty store merchandised in a full service case or modified atmosphere packaged and labeled with a source verified and branded (+ $7.21/kg) label claim (P < 0.05). Shoulder and loin chop prices analyzed via hedonic modeling were not different for store location (East, Central, and West) nor USDA process verified Never-Ever 3 claim (P > 0.05).

Additionally, this research indicated that lamb loin and rib chops purchased at U.S. retail markets originating from U.S. lamb were the most muscular. Loin eye area of loin chops from U.S. origin were greater (19.55 cm2) than Australian chops (16.77 cm²), and chops from New Zealand (14.52 cm²) were the least muscular (P < 0.05). Also, Australian lamb (0.64 cm) had a trimness advantage of external fat of loin chops compared to lamb originating from either the U.S (0.84 cm) or New Zealand (0.86 cm; P < 0.05).

Lamb producers should strive to place a strategic emphasis on quality attributes identified in this research to ensure eating satisfaction and lamb flavor are optimized for American Lamb, and to produce lamb with product authenticity attributes requested by retail and foodservice sectors, and inevitably American lamb consumers.

An important application of the research included the development of an American lamb quality mission to: improve the consistency of quality, cutability, and marketability of American lamb with a consumer driven focus. The final phase of this project was a sheep/lamb industry strategy workshop that identified goals to: 1) Address factors contributing to lamb flavor, their impact on consumer satisfaction, and align flavor characteristics with target markets; 2) Improve lamb management to hit market-ready targets for product size, composition, and eating satisfaction while reducing production costs; and 3) Identify and capitalize on market opportunities for American lamb. A continuous improvement mentality is essential to lamb quality management throughout the supply chain in order to maintain (and increase) market share and demand for American lamb.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The aim of this study was to investigate the effect of feedlot production on the growth and carcass characteristics, as well as the distribution of the main tissues (muscle, fat and bone) and meat quality of Merino, South African Mutton Merino (SAMM) and Dorper lambs. The Merino and SAMM 2008 outperformed (P<0.05) the 2007 SAMM and both Dorper production groups in terms of average daily gain, while the Merino and both SAMM production groups achieved the best feed conversion ratio (P<0.05). The highest percentage A2 graded carcasses was achieved after 42 days under feedlot conditions by the Merino and both Dorper production groups, but it took only 21 days in the feedlot for the SAMM lambs to achieve the same result. Slaughter weight, carcass weight and dressing percentage all increased significantly with an increase in the number of days under feedlot conditions for all three breeds, while a decrease in the percentage head, trotters and red offal was also documented. The fatter retail cuts (thick rib, flank, prime rib and loin) increased (P<0.05) in percentage with an increase in the number of days under feedlot conditions. A significant decrease in the percentage leaner retail cuts (raised shoulder and hind-quarters) was found when the amount of days under feedlot conditions increased. The highest profit is obtained by the prime rib, loin and hind-quarters in a lamb carcass. For the Merino and Dorper lambs these three cuts, or a combination of the three showed the highest combined percentages after 42 and 63 days under feedlot conditions, respectively. The late maturing SAMM lambs achieved the highest percentages for these three cuts after 63 and 84 days under feedlot conditions in 2007 and 2008 respectively. Visceral and renal fat deposition increased throughout the production period for all breeds. The Dorper lambs attained the highest subcutaneous fat depth, and also produced the heaviest, but fattest carcasses. For A2-graded carcasses, Dorper lambs had the highest dressing percentage and lowest subcutaneous fat depth, followed by the SAMM and then Merino breed. A decrease in the percentage muscle and bone was found with an increase in the number of days under feedlot conditions, whilst an increase in the percentage fat was found under the same conditions. Meat quality was mostly affected by the 48h post mortem pH. This pH value is affected by the cooling rate of the carcasses, which in turn is affected by the level of carcass fatness. Carcass fatness increased with an increase in the number of days under feedlot conditions, resulting in a low 48h post mortem pH. A low 48h post mortem pH is accompanied by higher percentages of cooking and drip loss, as well as a high a*-colour reading for all three breeds.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van voerkraalproduksie op die groeivermoë, karkaseienskappe, verspreiding van spier, been en vet, en vleiskwaliteit van Merino, Suid-Afrikaanse Vleismerino (SAVM) en Dorperlammers te bepaal. Die Merino en SAVM 2008 produksiegroepe het hoër (P<0.05) gemiddelde daaglikse toenames getoon as die SAVM 2007 en beide Dorper groepe, terwyl die Merino en beide SAVM produksiegroepe die beste voeromset verhoudings bereik het (P<0.05). Die hoogste persentasie A2 gegradeerde karkasse is na 42 dae in die voerkraal deur die Merino en beide Dorper produksiegroepe geproduseer, terwyl dit slegs 21 dae onder dieselfde toestande vir die SAVM groepe geneem het om dieselfde resultaat te lewer. Daar is ‘n betekenisvolle verhoging in slagmassa, karkasmassa en uitslagpersentasie vir al drie die rasse gevind met ‘n toename in die aantal dae in die voerkraal, terwyl ‘n afname in die persentasie kop, pote en haarslag gevind was. Die persentasie vetter groothandelsnitte (dikrib, dunrib, ribtjop en lendesnit) het toegeneem (P<0.05) met ‘n toename in die aantal dae in die voerkraal. ‘n Betekenisvolle afname in die persentasie van die maerder groothandelsnitte (blad en boude) is gevind met ‘n toename in die aantal produksie dae in die voerkraal. Die hoogste inkomste van ‘n lamkarkas is afkomstige van die ribtjop, lende snit en boude. ‘n Kombinasie van hierdie drie snitte was die hoogste vir die lammers van die Merino en beide Dorper groepe na 42 en 63 dae in die voerkraal onderskeidelik. Die laat volwasse SAVM lammers het die hoogste persentasie van hierdie drie snitte bereik na 63 en 84 dae in die voerkraal vir die SAVM 2007 en SAVM 2008 onderskeidelik. Die neerlegging van pensvet en niervet het voortdurend toegeneem deur die produksieperiode vir al drie rasse. Die Dorperlammers het die hoogste onderhuidse vetneerlegging getoon, maar het ook die swaarste en vetste karkasse geproduseer. Dorperlammers het die hoogste uitslagpersentasie en laagste onderhuidse vetneerlegging vir A2 gegradeerde karkasse gehad, gevolg deur die SAVM en Merino. ‘n Afname in die persentasie spier en been in karkasse is waargeneem namate die lammers langer in die voerkraal was, terwyl ‘n toename in die persentasie vet onder dieselfde omstandighede waargeneem is. Die 48h post mortem karkas pH affekteer die meeste vleiskwaliteit eienskappe. Hierdie pH waarde word weer deur die tempo van karkasafkoeling beϊnvloed, wat op sy beurt deur die vetheidsgraad van die karkas bepaal word. Die vetheid van karkasse het toegeneem met ‘n toename in die aantal dae in die voerkraal, wat ‘n lae pH waarde 48h post mortem tot gevolg gehad het. ‘n Lae 48h post mortem pH waarde het gelei tot hoër persentasies kook- en dripverliese en hoë a* kleurlesings vir al drie rasse.

Tenderness, juiciness, colour and flavour are the most important meat quality attributes affecting the consumer acceptance. Maintaining the consistency of meat products by avoiding variable quality has become a major concern and great challenge to the meat industry. This in turn will also benefit meat end-users in the marketplace by having more tender meat. The present study was designed to evaluate the overall effects of pre-rigor infusion with kiwifruit juice, which contains the plant protease, actinidin, on lamb quality. A total of 18 lambs (12 months old) were divided into three treatment groups (6 lambs per each treatment). After exsanguination, lamb carcasses were infused (10% body weight) with fresh kiwifruit juice (Ac), water (W) and compared with a noninfusion treatment which acted as a control (C). Samples from different muscle/cuts (longissimus dorsi (LD) vs leg chops) at different post-mortem times (1 day post-mortem vs. 3 wks vacuum packaged storage at 2°C) and display time (0 to 6 days after the post-mortem storage) were analysed to monitor the changes on meat physical properties (e.g., tenderness, temperature, drip and cooking loss, colour), biochemical changes (pH, proteins and lipids) and volatile flavour compounds after the infusion treatments. The most tender meat (lowest shear force values) (P < 0.001) detected in the Ac carcasses post-mortem compared with C and W carcasses demonstrated that kiwifruit juice was a very powerful meat tenderizer, and could contribute to the meat tenderization process efficiently and effectively. Compared with C and W carcasses, the enhanced proteolytic activity (P = 0.002) resulting from the actinidin in kiwifruit juice in Ac carcasses caused degradation of the myofibrillar proteins and the appearance of new peptides during postmortem ageing. A slight positive effect in a*-value (redness) and decreased lipid oxidation, found in leg chops, was thought to be caused by the natural antioxidants in kiwifruit juice. Kiwifruit juice infused into the meat did not alter (P > 0.05) the volatile flavour compound profile indicating that the meat from Ac treated carcasses maintained its natural lamb flavour. No treatment differences were found for the temperature decline (P > 0.05) between the infused treatments and C. The higher rate of pH decline (P < 0.05) found in W carcasses might have contributed to the higher drip and cooking loss. The unbound water in meat might contribute to the higher L*-values (lightness) found in W carcasses. In summary, the proteolytic tenderizing infusion treatment using kiwifruit juice is a feasible approach for the commercial meat industry to increase profits, and also could satisfy the eating quality standards required by the consumers. In addition, tenderizing meat by using kiwifruit juice could also provide the kiwifruit processors an additional option for use of their product to gain a more profitable return.

Video Image Analysis (VIA) is a digital camera based technology that extracts relevant information from images using purpose tailored image processing software. In the present work, the VSS2000 image analysis system from E+V Technology GmbH has been used in a large lamb abattoir to determine the value of carcasses in an objective, consistent and automated way. In this thesis results are reported of several experiments conducted within the framework of two UK-funded projects. The aims of the research were (i) the calibration and validation of the VIAtechnique for the evaluation of lamb carcasses under UK abattoir conditions, with the view to scientifically examine the accuracy and precision of information from the VIA systems as the basis for a value-based marketing system, (ii) to investigate the use of VIA measurements (weights of primal meat yields and carcass dimensional measurements) in sheep breeding programmes to improve carcass and meat quality and (iii) to evaluate the potential of this technology to reward increased carcass quality associated with the use of breeding strategies based on the inclusion of a quantitative trait locus (QTL) for improved muscularity. Accuracy, precision and consistency of The Meat and Livestock Commission (MLC) carcass classification scheme, currently used in UK abattoirs to evaluate carcass quality, was compared against the VIA system in the prediction of various primal joint weights. The results highlighted the advantage of the VIA system being on average 2% more accurate (measured as coefficient of determination: R2) and 12% more precise (measured as root meat squared error: RMSE) in predicting weight of primal meat yields (leg, chump, loin, breast and shoulder) of the lamb carcasses than the MLC carcass classification scheme. The genetic analysis of VIA-based predicted primal joint weights showed substantial additive genetic variance, suggesting that their use in sheep breeding programmes could improve carcass quality either by an improvement of conformation or by an increased weight of the most valuable primal cuts, without an increase in fatness. Favourable associations between VIA primal weights and performance traits indicate that selection based on VIA traits is possible without a negative effect on average daily gain, live weight and cold carcass weight. Although computer tomography (CT) and dissection found in related studies significant effects of a Texel muscling-QTL (TM-QTL) for increased muscularity in the loin region, in the present study they could not be identified by both, the current industry carcass evaluation system for conformation and fatness and the VIA system. A calibration of the VIA system against CT measurements resulted in improved VIA prediction equations for primal meat yields and also showed a moderate potential to estimate loin muscle traits measured by CT and to detect partially the effect of the TM-QTL on these traits. The results of the research demonstrated that VIA is a consistent method to measure carcass composition and that it improved the prediction (accuracy and precision) of primal meat yields compared to the present MLC scoring system. The estimated genetic parameters for VIA primal meat yields suggested that selection for increased lean meat yield from lamb carcass measured using VIA can contribute to genetic improvement of carcass quality without increasing carcass fatness. The results suggest that VIA technology installed in abattoirs could provide the means for the development of a value-based marketing system by paying for weights of the most valuable primal cuts measured using VIA.

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: In many parts of the world, soil is depleted of selenium (Se), leading to selenium-poor plants, animals and, therefore, humans. It was recognised that a study to examine the functionality of new products on the market to address this problem was required. The purpose of this research were threefold: to compare the effects of sodium selenite (NaSe) and organically bound selenium sources on small ruminant performance, to investigate the bioavailability of these Se sources, and analyse their influence on carcass characteristics, meat quality and antioxidant capabilities. Fourty growing Döhne Merino wethers from the Southern Cape region, a selenium-deficient area, were used for the study. The animals were all fed the same basal diet in the adaptation period and were then allocated to one of four treatment groups: Control (CT), inorganic selenium (IS), organically bound Se A (OSA) or B: (OSB). The period of supplementation was 90 days. This first study assessed the effect of the different Se sources on growth and Se bioavailability in the wethers. The wethers and the feed they consumed were regularly weighed to determine their growth and feed conversion rate (FCR) in the trial period. To gauge their Se level, blood samples were collected via jugular venipuncture at monthly intervals. The wool around the jugular was shorn and samples were collected on day 0 and day 90 for comparative Se level analysis. Liver, skeletal muscle and kidney samples were collected at day 90, directly after slaughter, to determine the Se level in these tissues. No effect could be reported in the growth and FCR of the wethers between the supplementation groups. For whole blood Se levels there was an effect in the early part of the study, with a greater increase in Se levels for the organically bound Se groups, but in the end no effect on whole blood levels could be seen between the different Se treatments. Neither could any difference between the inorganic Se and organic bound Se treatments be found in the liver – however, the total Se concentration of the wool, kidney and meat samples was greater in those animals offered organically bound Se when compared with those receiving a comparable dose of inorganic Se. The second study evaluated the antioxidant capabilities of the different Se supplements in the wethers. Blood samples were taken monthly for plasma collection to test for Glutathione peroxidase (GSH-Px) activity and total antioxidative capacity (TAC) with the oxygen radical absorbance capacity (ORAC) assay. Liver, skeletal muscle and kidney samples were collected at day 90, immediately after slaughter and measured for GSH-Px activity. With TAC, there was a significant effect for the treatment period between day 0 and day 90, however the treatments did not show any significant difference. No significant differences could be established between the different Se treatments for the GSH-Px analysis in any of the tissues. For the mean plasma values of the treatments no significant differences can be reported, but a significant difference was observed at day 30 in the contrast between the organically bound Se and the other treatment groups. The third study was to evaluate the quality and lipid oxidation of muscle from those wethers supplemented with different Se sources. Skeletal muscle samples were collected at day 90, directly after slaughter to determine this. No differences in the meat quality of the wethers could be detected between Se sources after the 90-day supplementation period. Lipid oxidation was measured by determining TBA reactive substances (TBARS) and once again no differences could be detected. Based on the results found in this investigation, it may be inferred that organically bound Se (OSA & OSB) supplementation will hold a number of advantages for small ruminants over inorganic Se supplementation. Animals fed the organically bound Se had reached adequate Se levels sooner on the organically bounded treatments than the inorganically bounded treated animals. The greater bioavailability of organically bounded Se over inorganic Se was proven by the increased Se levels in certain tissues and organs. Additionally, only the organically bounded Se could find a pathway to the wool, confirming that it was carried in an organic form (probably selenomethionine) in the body. Organically bound Se will therefore have a positive impact on small ruminant health and production, which will result in an indirect advantage for consumer health.
AFRIKAANSE OPSOMMING: Die grond in groot dele van die wêreld word selenium-arm en dit lei na selenium-arm plante, diere en mense. Dit is waargeneem dat ‘n studie wat kyk na die funksionaliteit van nuwe produkte op die mark om die probleem aan te spreek nodig is. Die doelwit van die studie was om verskillende selenium (Se) bronne te vergelyk en die uitwerking daarvan op klein herkouer prestasie te evalueer. Daar is gekyk na die biobeskikbaarheid, invloed daarvan op die karkas eienskappe en antioksidant vermoëns van die verskillende Se bronne. Veertig groeiende Dohne Merino-hamels van die Suid-Kaap-streek, 'n Se arm gebied is gebruik vir die studie. Die diere is almal dieselfde basale dieet gevoer in die aanpassing periode en dan toegeken aan een van vier behandelings: kontrole (CT), anorganiese Se (IS), organies gebinde Se A (OSA) of B: (OSB). Die tydperk van die aanvulling was 90 dae. In die eerste studie is gekyk na die effek van die verskillende bronne van Se op die groei en die biobeskikbaarheid daarvan aan die hamels. Die hamels en voer verbruik, is gereeld geweeg sodat hul groei en voer omset verhouding (VOV) in die proef tydperk te bepaal. Bloedmonsters is versamel deur middel van die jugulêre venipuncture vir die Se vlak bepaling daarvan. Lewer, skeletspier en nier monsters is versamel op dag 90, direk na die slagting vir die Se vlak bepaling. Die wol rondom die nekslagaar is geskeer en monsters is versamel op dag 0 en 90 vir Se vlak analise. Geen effek kan gerapporteer word vir die groei en VOV van die hamels tydens die aanvullings periode nie. Vir die bloed Se vlakke was daar 'n uitwerking in die vroeë deel van die studie, met 'n vinniger toename in Se vlakke vir die organies gebinde Se groepe, maar aan die einde kon geen effek gesien word tussen die verskillende Se behandelings nie. Geen verskil tussen die NaSe en organiese gebonde Se behandelings kon gevind word in die lewer nie. Die totale Se konsentrasie van die wol-, nier-en vleis

O objetivo do presente trabalho foi analisar o comportamento do consumidor de carne ovina considerando a percepção de qualidade através das pistas e atributos de qualidade. Foram utilizados dois métodos de entrevistas: presencial com consumidores de uma loja especializada em carnes na cidade de Porto Alegre, Estado do Rio Grande do Sul, e questionários online. Ao total, foram entrevistadas 207 pessoas, sendo que 100 responderam o questionário no formato presencial e 107 no formato online. O questionário aplicado nas entrevistas foi classificado como estruturado e possuía cinco partes. A primeira, relacionada ao hábito de consumo de carnes de uma maneira em geral, a segunda parte, ao hábito de consumo da carne ovina, a terceira, relacionada ao hábito de consumo dos compradores de carne ovina, a quarta parte, sobre os estilos de vida dos entrevistados e a quinta e última referente a características sóciodemográficas. A terceira parte era apenas respondida por aqueles consumidores que também eram compradores de carne ovina. A análise estatística foi realizada por meio do software Standards Aligned System SAS/STAT 9.2, a partir do procedimento GLIMMIX (GLMM) (SAS, 2008). Inicialmente foi feita uma distribuição de frequência dos dados obtidos e posteriormente, foi analisada a possibilidade da formação de Clusters. Para a caracterização e melhor descrição de cada cluster utilizou-se a Análise Discriminante (STEPDISC), porém a estatística mostrou que não havia o nível de confiança suficiente para a formação de clusters. Na continuação da análise, foi realizada uma correspondência (The CORRESP procedure) e por último uma regressão estatística entre as variáveis, frequência de consumo e faixa etária, correlacionando a informação com as perguntas relacionadas aos atributos de qualidade. Os resultados obtidos demonstram uma tendência da carne ovina ser consumida pelo sexo masculino. No momento da compra, os homens e aqueles entrevistados que se encontraram na faixa etária de 31 a 40 anos possuíam maior disposição em participar na compra de carnes. As pistas de qualidade mais importantes nos atributos de busca em relação à frequência de consumo foram a cor e a gordura externa, e as que foram consideradas de mais baixa importância foram a marca e a propaganda. Nos atributos de confiança, a origem e a categoria do animal foram as mais importantes em relação à frequência de consumo. A influência da idade na percepção dos atributos de busca segue o mesmo comportamento da frequência de consumo, destacando que a gordura possui uma importância maior nas faixas etárias mais jovens. No caso dos consumidores com mais idade, estes dão maior importância para a embalagem e para as variedades de cortes. No atributo de confiança, as quatro pistas de qualidade possuíram maior importância para os consumidores mais jovens e as pistas de experiência seguem o mesmo comportamento.
The aim of this study was to analyze the consumer behavior of lamb meet considering the perception of quality cues and its quality attributes. Two interview methods were used: face-to-face interviews with consumers of a butcher boutique located in the city of Porto Alegre, state of Rio Grande do Sul, and online questionnaires. In total, 207 people were interviewed in which 100 people answered the face-to-face questionnaire and a 107 the online questionnaire. The questionnaire applied in the interviews is classified as structured and owns five chapters. The first one related to the habits of meat consume in a general way, the second chapter, considers the habits of lamb meat consume, the third chapter, regards the habits of lamb consume buyers, the fourth chapter, investigates about interviewers lifestyle and the fifth and last chapter refers to socio demographic characteristics. The third chapter was only answered by those consumers who actually were also buyers of lamb meet. The statistical analysis was performed using the Standards Aligned System software SAS / STAT 9.2, The GLIMMIX Procedure (GLMM) (SAS, 2008). Initially, a frequency distribution of data obtained was made and subsequently the possibility of forming clusters analyzed. To better characterize and descript clusters the Discriminant Analysis (STEPDISC) was used, however, statistical shows there was no sufficient confidence level for the formation of clusters. In further analysis, we performed a data correspondence (The CORRESP procedure) and finally a statistic regression between variables, frequency of meat consumes and age group, correlating the information with the questioning related to the quality attributes. The results show that there is a trend in lamb consume that are higher between male sex representatives. At the specific moment of purchase, men and those respondents who are within the age group of 31 to 40 years have a higher willingness to participate in the purchase of meat. The quality cues most important in search quality attributes regarding the frequency of consumption were the color and external fat and those considered of lower importance were branding and advertising. In confidence attributes, origin and animal category were the most important in relation to the frequency of consumption. The influence of age in the perception of search attributes follows the same behavior of frequency of use, highlighting that fat having a great importance within the younger age groups. For older consumers, the packaging and to the varieties of cuts have greater importance. When analyzing confidence attributes, the four quality cues are the ones with greater importance to youngest consumers group and the experience cues follows the same behavior.

A busca por produtos mais saudáveis e minimamente processados tem levado indústrias e pesquisadores a estudarem novas formas de preservação de alimentos. Os objetivos deste trabalho foram: 1) avaliar o efeito da embalagem com atmosfera modificada (ATM) na preservação de lombo ovino armazenado sob refrigeração e 2) Avaliar o efeito do processamento em alta pressão na conservação de carne bovina marinada e com teor de sódio reduzido. Em ambas as pesquisas, músculos Longissimus lumborum foram submetidos à contagem microbiana, avaliação de cor, pH, oxidação lipídica (TBARS), perdas por cocção (PPC) e força de cisalhamento. Para o estudo do efeito da embalagem em atmosfera modificada, as amostras foram acondicionadas em cinco sistemas de ATM, 15% O2 + 85% CO2; 30% de O2 + 70% de CO2; 45% de O2 + 55% de CO2; 60% de O2 + 40% de CO2 e Vácuo (controle) e armazenadas a 1°C durante 21 dias. As análises de cor, pH, TBARS, PPC e força de cisalhamento foram realizadas a cada sete dias e as microbiológicas duas vezes por semana. Diferentes concentrações de oxigênio dentro da embalagem trouxeram diferença significativa na intensidade de cor vermelha das carnes armazenadas em ATM. Até o sétimo dia de estocagem tratamentos com maior quantidade de O2 apresentaram melhor coloração, após esse período embalagens a vácuo conseguiram preservar melhor a mioglobina. Diferentes concentrações gasosas não trouxeram causaram diferença (p> 0,05) no pH da carne entre tratamentos. Nenhuma diferença significativa entre tratamentos foi encontrada para amostras embaladas em ATM nos parâmetros perda de peso por cocção e força de cisalhamento. A embalagem em atmosfera modificada foi capaz de retardar o crescimento da microbiota presente na carne. Isso levou á preservação da amostra por até 18 dias sob refrigeração, enquanto amostras a vácuo tiveram uma vida útil de 11 dias. Para o estudo do efeito da alta pressão em carne marinada com baixo teor de sódio, as carnes foram inoculadas com 106 UFC/g de carne com E. faecium e Listeria innocua e em seguida marinadas durante 18 horas, a 4°C, em diferentes soluções: 1% NaCl + 1% ácido cítrico, 1% NaCl + 2% ácido cítrico, 2% NaCl + 2% ácido cítrico e 2% NaCl + 2% ácido cítrico. Após a marinação as amostras foram submetidas ao tratamento nas seguintes pressões: Zero (controle), 300MPa, 450Mpa, 600MPa. As análises físico-químicas e microbiológicas foram realizadas logo após o tratamento. O tratamento em alta pressão foi capaz de reduzir a população microbiana em até seis ciclos logarítmicos quando 600Mpa foram aplicados em todas as soluções estudadas. A não aplicação de alta pressão proporcionou a redução de apenas um ciclo log na população de E. faecium quando as carnes foram marinadas com 2% NaCl + 2% ácido cítrico. A alta pressão e as diferentes concentrações de sal e ácido, não trouxeram diferença significativa na coloração das amostras. Já o maior teor de ácido cítrico na marinada causou maior (p<0,05) redução do pH da carne em comparação com as amostras em baixa concentração de ácido. Os experimentos demonstraram que a tanto embalagem a vácuo quanto a aplicação de ácido cítrico foram eficientes em retardar a oxidação lipídica. Pressões de 600Mpa tornaram a carne significativamente mais dura que as demais pressões aplicadas. Os resultados demonstraram a possibilidade de extensão da vida útil da carne refrigerada através da aplicação de diferentes tecnologias: a embalagem com atmosfera modificada para carne fresca e processamento em alta pressão de carnes marinadas com reduzido teor de sal.
The seek for healthier and minimally processed foods has led industries and researchers to study new forms of food preservation. The objective of this project was 1) to evaluate the effect of modified atmosphere packaging (MAP) in the preservation of lamb loin stored under refrigeration and 2) to evaluate the effect of high pressure on the conservation of marinated beef with reduced sodium content. In both cases, Longissimus lumborum muscles were submitted to microbial count, color evaluation, pH, lipid oxidation (TBARS), cooking losses (CL) and shear force. To study the effect of modified atmosphere packaging, the samples were placed into five MAP systems, 15% O2 + 85% CO2; 30% O2 + 70% CO2; 45% O2 + 55% CO2; 60% O2 + 40% CO2 and vacuum (control) and stored at 1 ° C for 21 days. The color, pH, TBARS, CL and shear force analyzes were performed every seven days and microbiological loads counted twice a week. Different concentrations of oxygen in the headspace brought significant difference in the redness of samples packed in ATM. Until the seventh day of storage the treatments with higher concentration of O2 showed a better color, thereafter vacuum packaging managed to best preserve the myoglobin. Different gas concentrations have not brought significant difference (p> 0.05) in the pH of the meat among treatments. No significant difference among treatments was found for samples packed in ATM for cooking loses and shear force parameters. The modified atmosphere packaging was able to retard the growth of microbial flora on meat. This led to the preservation of the sample for up to 18 days under refrigeration, while samples in vacuum had a shelf life of only 11 days. To evaluate the effect of high pressure in marinated meat, the steaks were inoculated with 106 CFU / g of meat with E. faecium and Listeria innocua and then marinated for 18 hours at 4°C in different solutions: 1% NaCl + 1% citric acid, 1% NaCl + 2% citric acid, 2% NaCl + 2% citric acid and 2% NaCl + 2% citric acid. After marination, samples were subjected to the following pressures: 600MPa, 450MPa, 300MPa and 0MPa (control). The physicochemical and microbiological analyzes were conducted soon after treatment. The high pressure treatment was able to reduce six log cycles of the microbial population when 600MPa was applied to all solutions studied. Without high pressure application, the reduction was only of 1 log cycle in the population of E. faecium when the samples were marinated with 2% NaCl+ 2% acid. The high pressure and different sodium and acid concentrations did not bring difference in the color of the samples. Higher citric acid content in the marinade caused higher (p <0.05) reduction of the pH of the meat, compared with samples of low concentration of acid. In order to slow down lipid oxidation, the experiments demonstrated that both vacuum packaging and citric acid are efficient implementation. The application of 600MPa made the meat significantly tougher than the meat treated with other pressures. The results demonstrated the possibility of extending the shelf-life of the chilled meat by applying different technologies: modified atmosphere packaging for fresh meat and marination of meat with reduced salt content by high pressure use.

One of the main drivers influencing consumers in the purchasing of red meat is the level of visible fat, and this is particularly important in lamb, with lamb often being perceived as fatty. Consumer-driven preference for leaner meat, coupled with the meat processing industries preference for a reduction in carcass fat, increasing lean meat yield and reducing waste, have led to continued selection for lean growth and reduced fatness in several meat producing species The perception of lamb being fatty could be directly targeted in isolation by reducing overall fat levels, however there are related effects on meat (eating) quality, and the combined improvement and consistency of meat (eating) quality and the reduction of overall fatness is more complicated. It is apparent that fat content plays a significant role in meat (eating) quality. Generally four major fat depots are recognised in animal carcasses, these are: subcutaneous (under the skin); internal organ associated; intermuscular (between muscles and surrounding muscle groups); and intramuscular (marbling, between muscle fibres), the latter generally regarded as having the greatest association with meat (eating) quality. X-ray computed tomography (CT) can measure fat, muscle and bone in vivo in sheep and CT predictions of carcass composition have been used in commercial UK sheep breeding programmes over the last two decades. Together with ultrasound measures of fat and muscle depth in the loin region, CT measured carcass fat and muscle weights have contributed much to the success of breeding for leaner carcasses and increased lean meat yield. Recently it has also been considered that x-ray computed tomography provides the means to simultaneously estimate IMF and carcass fat in vivo. Thus the aim of this project is to investigate the use of two and three-dimensional x-ray computed tomography techniques in the estimation of meat (eating) quality traits in sheep, and to further investigate the genetic basis of these traits and the possibility of their inclusion into current breeding programmes. The primary approach was the use of two-dimensional x-ray computed tomography, determining the most accurate combination of variables to predict IMF and mechanical shear force in the loin. The prediction of mechanical shear force was poor with accuracies ranging from Adj R2 0.03 – 0.14, however the prediction of IMF in the loin was more promising. CT predicted carcass fat weight accounted for a moderate amount of variation in IMF (R2 =0.51). These accuracies were significantly improved upon by including other information from the CT scans (i.e. fat and muscle densities, Adj R2 >0.65). Average muscle density in a single or multiple scans accounted for a moderate amount of the variation in IMF (Adj R2 = 0.51-0.60), and again accuracies R2 >0.65 were achieved, independent of CT-measured fat areas or predicted fat weights. Similar results were achieved with the use of three-dimensional CT scanning techniques (Adj R2 0.51 – 0.71), however, there was a dramatically increased requirement for image analysis when compared to two-dimensional techniques, and the increase in accuracy was not significant. This suggests that the current method of two-dimensional image capture is sufficient in the estimation of IMF in vivo in sheep. The prediction equations developed as part of this work were applied across divergent breed types (Texel, Scottish Blackface and Texel cross mule), to investigate the transferability of the prediction equations directly across to other breeds of sheep. As part of this study, the IMF levels across the breed types and sexes were also compared and found that IMF was significantly affected by breed type (P<0.001) with Scottish Blackface lambs having higher levels of IMF when compared to Texel cross mule lambs, and the lowest levels of IMF were in the purebred Texel lambs at the same liveweight or similar levels of carcass fatness. Sex also had a significant effect on IMF across breeds (P<0.001) with females having higher levels of IMF at similar levels of both carcass fat and liveweight, and within breed, females had significantly higher levels of IMF in both the purebred Texel and Scottish Blackface lambs, when compared at similar levels of carcass fat and liveweight (P<0.05). Using the models previously developed in purebred Texel to predict IMF in the Scottish Blackface and Texel cross mule, accuracies were found to be R2 = 0.57 – 0.64 and R2 = 0.37 – 0.38 respectively. Providing evidence that the equations are transferable across to some breeds more successfully than others, however, given that there is currently no method of accurately estimating IMF in vivo, accuracies across to both breeds are acceptable. The genetic parameter estimation was unsuccessful using the same research-derived dataset as previously employed in the study. However the ambition was always to investigate the genetic relationships between traits in a large industry dataset, exploiting the wealth of commercial CT information available. These investigations were considerably more successful, and among the first to present genetic parameters of novel CT-derived IMF estimates. The results found moderate heritability estimates of h2 0.31 and 0.36 for the final selected prediction equations, with clear indications that one model not including CT predicted carcass fat or any other fat measures, was more independent of these measures and the two separate prediction methods were highly genetically correlated with each other (rg = 0.89). The results from this study show that not only is it possible to accurately estimate IMF levels in the loin of Texel sheep using CT scanning, but that, until breed specific predictions are developed, the methods developed in this study are transferable across some breed types. The results also show that CT predicted IMF is heritable, independent of overall fatness and has the potential to be included in current breeding programmes. These findings can now be used to develop breeding programmes which enable breeders to make the best use of CT scanning technology to improve carcass composition while maintaining or possibly improving aspects of meat (eating) quality.

Thesis (MScAgric)--Stellenbosch University, 2008.
ENGLISH ABSTRACT: The aim of this study was to investigate the effect of South African production system (feedlot {FL-} or free-range {FR-}) and gender (ewes, rams or castrates) on growth and carcass characteristics of Dorper sheep. Male lambs (castrates and rams) grew twice as fast as ewes (P<0.05) under FL-conditions while much smaller differences were observed between gender groups in FR-lambs. FL-lambs produced heavier carcasses (P=0.0003) with higher dressing percentages (P<0.05) and greater carcass fatness levels (P<0.052) than FR- lambs. No differences attributable to production system were found on meat tenderness (as indicated by Warner Bratzler shear force strength) and on the intramuscular lipid concentration. In contrast, sensory evaluation results suggested that meat from FL-lambs was juicier and more tender than meat from FR-lambs. The sensory panel could not distinguish between FL and FR meat as far as the attributes of aroma and flavour were concerned. Cholesterol results indicated that for intermuscular fat, higher cholesterol levels were observed for FL-lambs than for FR-lambs. The level of palmitic acid (C16:0) was significantly higher (P=0.0375) in the Longissimus dorsi (LD) muscles of FL-lambs. For intramuscular fat from the Biceps femoris (BF) muscle, g-linolenic acid (C18:3n-6) was higher (P<0.0001) in FL- lambs. Results for intramuscular BF further indicated that ram lambs had the highest (P=0.0019) palmitic acid (C16:0) and sum of TUFA (P=0.0014), castrates had the highest (P=0.0260) α-linolenic acid (C18:3n-3) and g-linolenic acid (C18:3n-6), while ewe lambs had the highest (P=0.0014) SFA concentrations. Linoleic acid (C18:2n-6c) was significantly higher (P=0.0067) in the subcutaneous fat of FL-lambs while FR-lambs had more linolenic acid (C18:3n-3). For the kidney fat, FR-feeding increased (P < 0.05) stearic (C18:0), linolelaidic (C18:2n-6t), α-linolenic (C18:3n-3) and homo-g-linolenic acid (C20:3n-6) percentages. Conversely, linoleic acid (C18:2n-6c) was increased (P=0.0372) by FL-feeding. For the intermuscular fat, FR-lambs had higher linolenic acid (C18:3n-3) and SFA (P=0.0113 and P=0.0341) compared to FL-lambs. On the other hand, the sum of TUFA for the intermuscular fat was higher (P=0.0341) in FL-lambs compared to FR-lambs. Results from the study imply that the consumer may not necessarily be able to discern between meat from FR- or FL-lambs, although they may possibly discriminate against the increase in visible fatness of FL-lambs. No clear advantage of production system in terms of human health could be demonstrated as far as the proximate chemical composition and the fatty acid composition of the meat was concerned. The faster growth and the associated shorter production cycle of FL-lambs could be an advantage under certain production systems. However, it needs to be weighed against the cost of concentrate feeding and the preference consumers are likely to develop for lamb produced in natural environments.
AFRIKAANSE OPSOMMING: Die doel van die studie was om Suid Afrikaanse produksiestelsel (voerkraal {VK-} of veld {VD}) en geslag (ooie, hamels of ramme) op die groeivermoë en karkaseienskappe van die Dorperskape te bepaal. Manlike lammers (ramme and hamels) het twee keer vinniger (P<0.05) as ooilammers onder VK-toestande gegroei, terwyl kleiner verskille tussen geslagsgroepe by VD-diere waargeneem is. VK-lammers het swaarder karkasse (P=0.0003), hoër uitslagpersentasies (P<0.05) en meer karkas vet (P<0.052) as VD -lammers vertoon. Geen verskille as gevolg van produksiestelsel is op die sagtheid van vleis (soos aangedui deur Warner-Bratzler skeurkragwaardes) en die binnespierse vetinhoud gevind nie. Daarenteen het sensoriese analises aangedui dat vleis van VK-lammers sappiger en sagter as vleis van VD- lammers was. Die sensoriese paneel kon nie verskille aangaande die aroma en geur van vleis tussen VK- en VD-vleis onderskei nie. Cholesterolvlakke was hoër vir VK-lammers as by VD-lammers. Die vlak van palmitiese suur (C16:0) was hoër (P=0.0375) in die Longissimus dorsi (LD) spier van VK-lammers. Vir binnespierse vet van die Biceps femoris (BF) spier was g-linoleniese suur (C18:3n-6) hoër (P<0.0001) in VK-lammers. Resultate vir binnespierse vet van die BF spier het verder bewys dat ramlammers die hoogste (P=0.0019) palmitiese suur (C16:0) and totale onversadigde vetsure (P = 0.0014) getoon het, hamels die hoogste (P=0.0260) α-linoleniese suur (C18:3n-3) en g-linolenese suur (C18:3n-6) getoon het terwyl ooilammers die hoogste (P=0.0014) versadigde vetsuurvlakke getoon het. Linoliese suur (C18:2n-6c) was hoër (P=0.0067) in die onderhuidse vet van VK-lammers terwyl VD-lammers meer linoliese suur (C18:3n-3) gehad het. Resultate vir niervet het getoon dat VD-voeding die persentasies van steariese (C18:0), linoleladiese (C18:2n-6t), α-linoleniese (C18:3n-3) and homo-g-linoleniese suur (C20:3n-6) verhoog (P<0.05) het relatief tot VK-voeding. Linoliese suur (C18:2n-6c) is deur VK-voeding verhoog (P=0.0372). Vir intermuskulêre vet het VD-lammers hoër linoleniese suur (C18:3n-3) en versadigde vetsure (P=0.0113 en P=0.0341) as VK-lammers gehad. Die totale onversadigde vetsure vir tussenspiere vet was hoër (P=0.0341) in VK-lammers in vergelyking met VD-lammers. Resultate van hierdie studie dui daarop dat verbruikers nie noodwendig tussen vleis van VD- en VK-lammers sal onderskei nie, alhoewel hulle dalk teen die sigbaar vetter vleis van VK-lammers kan diskrimineer. Geen definitiewe voordeel in terme van menslike gesondheid kon op grond van die chemiese samestelling van die vleis bevestig word nie. Vinniger groei van VK-lammers, en die korter produksiesiklus wat daarmee verband hou, mag onder sekere produksie stelsels ʼn voordeel wees. Die voordeel moet teen die hoër koste van VK-voeding en die voorkeur van verbruikers vir lam produksie in natuurlike omgewing opgeweeg word.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
A carne ovina à um produto altamente rico em proteÃnas, com baixo teor de gordura e muito valorizado no mercado internacional. PorÃm, vÃrios fatores responsÃveis pela caracterizaÃÃo da qualidade da carne contribuem para a baixa popularidade desse produto no paÃs, tais como operaÃÃes de prà e pÃs-abate mal realizadas, abate de animais velhos, manejo inadequado, tÃcnicas precÃrias de manuseio pÃs-abate, entre outros. Dessa forma, a pesquisa teve por objetivo avaliar a qualidade funcional e sensorial da carne ovina produzida e comercializada no Estado do Cearà a fim de detectar e melhorar as condiÃÃes que afetam a qualidade das carnes. No experimento, utilizou-se 6 animais provenientes de cinco procedÃncias do Estado do Cearà (P1- TauÃ, P2- Sobral, P3- QuixadÃ, P4- Caridade e P5- criatÃrio experimental da UFC), totalizando 30 cordeiros que variaram de seis meses a 1 ano de idade. ApÃs o abate, as carcaÃas permaneceram durante 24 horas em cÃmara fria a 0ÂC. Em seguida, foram divididas longitudinalmente em duas meia-carcaÃas. De cada animal, utilizaram-se os cortes paleta e perna da meia-carcaÃa direita e os dois lombos. As peÃas foram dessossadas e retiradas porÃÃes dos mÃsculos para cada anÃlise. As peÃas musculares foram embaladas em filmes de nylon-polietileno, seladas a vÃcuo e mantidas em congelamento atà a realizaÃÃo das anÃlises de pH, capacidade de retenÃÃo de Ãgua (CRA), perdas de peso por cocÃÃo (PPC), forÃa de cisalhamento (FC), cor medido pelos parÃmetros L*, a*, b*, H* e C*, composiÃÃo centesimal e anÃlise sensorial dos atributos de cor, sabor, maciez, suculÃncia e aceitaÃÃo global. Os valores de pH obtidos nas diferentes procedÃncias apresentaram diferenÃa significativa, sendo que a carne da procedÃncia P3 apresentou maior pH. Com relaÃÃo as propriedades CRA e PPC, houve significÃncia estatÃstica devida tanto aos cortes como Ãs procedÃncias estudadas, sendo que a procedÃncia P5 se destacou com maiores valores para as duas variÃveis. A FC nÃo apresentou significÃncia estatÃstica para as diferentes procedÃncias. No entanto, para as variÃveis da anÃlise de cor, a procedÃncia P5 apresentou valores de L*, a*, b*, H* e C* significativamente maiores que as demais procedÃncias. Com relaÃÃo à composiÃÃo centesimal, apenas o conteÃdo de cinzas na carne nÃo apresentou diferenÃas significativas entre as procedÃncias. Quanto à aceitaÃÃo sensorial, as procedÃncias P5 e P4 se destacaram em todos os atributos analisados (cor, sabor, maciez, suculÃncia e aceitaÃÃo global), ou seja, a criaÃÃo de ovinos em confinamento pode influenciar a aceitaÃÃo do produto pelos consumidores, uma vez que esse tipo de sistema gera animais em melhores condiÃÃes no momento do abate, o que determina a qualidade final da carne. Quanto à atitude de consumo, a procedÃncia P5 apresentou maior aceitaÃÃo e menor rejeiÃÃo, indicando essa como a mais aceita entre os provadores.
Lamb meat is rich in protein, low in fat content and highly valued in the international market. However, several factors responsible for the characterization of the meat quality contribute to a low popularity of this product in the local market. Among them the slaughter operations performed poorly, inadequate management of the animals and poor techniques of post-slaughter handling. Thus, the study aimed to evaluate the functional and sensory quality of lamb produced and marketed in the State of Cearà to detect conditions that affect the quality of the meat. In this experiment, six animals from five different locations of the State of Cearà (P1 - Taua, P2 - Sobral, P3 - QuixadÃ, P4 - Caridade and P5 - UFC) were used, totaling 30 lambs ranging from six months to one year of age. After slaughter, carcasses remained for 24 hours in cold storage at 0ÂC. They were then divided longitudinally into two half-carcasses. From each animal, were used the shoulder and the leg cuts from the right half carcass and the loins from the two half carcasses. The pieces were removed, bonned and the muscles separated for analysis. The muscle pieces were packed in nylon-polyethylene film, vacuum sealed and kept frozen until the realization of the following meat analysis: pH, water holding capacity (WHC), cooking loss (CL), shear force (SF), color, chemical composition and sensory analysis of color, flavor, tenderness, juiciness and overall acceptance. The meat pH values obtained from different locations showed significant differences, with P3 showing higher values than the other meats. Regarding the CRA and PPC analysis, statistical significance was observed for both the type of cut and the location of the animals where P5 showed the highest values for both variables. SF values were not different for the different locations of the animals. However, for the variables of color analysis, the results for P5 showed values for L*, a*, b*, H* and C* significantly higher than those for the other locations. With respect to meat composition, only the ashes were not significantly different among the locations. As for the meat sensory the animals from P5 and P4 performed better than those from the other locations in all the attributes evaluated (color, flavor, tenderness, juiciness and overall acceptance). Raising sheep in confinement may influence product acceptance by consumers, since this type of system produces animals with appropriate condition at slaughter, which influences the final quality of the meat. The attitude of the consumers related to the meat from P5 showed greater acceptance and less rejection of the meat.

In recent years, the concept of food quality has received a lot of attention from food producers and retailers as well as from public authorities and health educators. There are a lot of discusses a practical approach to defining the term ‘quality’. But although there have been many attempts to clarify and define the concept, there still no general agreement on the term (Grebitus et al, 2006). For European food industry, quality is a key factor because the high quality of a product is the basis for success in this highly competitive market. However, it is difficult to decide which sort of meat has the best nutrition value or technological properties (Kortz, 2003). Work object. To research and compare various animal meat quality and nutrition value. During investigation were taken 6 different sorts of animal and poultry meat samples: Lithuanian white pigs, Lithuanian black head sheep, Lithuanian black-white bulls, wild pork, Big-6 turkey broilers and Hybro G cross chicken broilers. For the samples was taken 500-550g from long back muscle (musculus longissimus dorsi). For poultry and turkey samples was taken breast meat. Pork, sheep, bulls, chicken and turkey broilers were raised and slaughtered in the same groups, had the same feeding and slaughtering conditions, wild pork was hunted in Lithuanian forests. Measuring different animals meat quality and nutrition features, samples were taken chilled 24 hours after slaughtering. Meat quality indexes were measured at ‘Meat... [to full text]

Dissertação de Mestrado Integrado em Medicina Veterinária
Ao longo dos anos têm sido efectuados diversos estudos na área de tecnologia alimentar, com o intuito do desenvolvimento de técnicas de prolongamento da vida útil dos produtos alimentares facilmente perecíveis, como a carne. Neste trabalho, foi avaliada a vida útil das costeletas de borrego de leite (IGP-Lechazo de Castilla e Léon) provenientes de carcaças sujeitas a dois protocolos diferentes de arrefecimento pós abate (convencional e lento), embaladas em duas atmosferas protectoras diferentes (alto e baixo teor de oxigénio), considerando um armazenamento de 13 dias em refrigeração. Esta avaliação foi efectuada através do estudo de parâmetros indicadores de qualidade, sendo realizadas análises microbiológicas, físico-químicas e sensoriais em dias específicos, de modo a verificar a influência destes factores na conservação da carne ao longo do tempo. Os resultados obtidos demonstraram que o tipo de arrefecimento utilizado não é muito relevante, mas que a utilização de embalagens de atmosfera modificada apresenta grande importância no prolongamento da vida útil da carne. O nosso estudo demonstrou vantagens diferentes em ambas as atmosferas, sendo que as de teor baixo em O2 apresentam propriedades antimicrobianas importantes no atraso da deterioração microbiológica, enquanto que as de alto teor de O2 favorecem características organolépticas visuais, essenciais na decisão de compra do consumidor.
ABSTRACT - Effect of different chilling methods and modified packaging under different mixtures of modified atmosphere on lamb chops shelf life - Several studies have been made in Food Technology area in order to develop techniques that allow extending the shelf life of products, such as fresh meat. In this project, the shelf life of lamb chops was analyzed. Lamb carcasses were submitted to two different post-slaughter chilling systems: conventional and delay-chilling. After the primary butchery of the carcasses, lamb chops were packaged under two different modified atmospheres – high and low O2, and stored for 13 days in refrigeration temperatures. Microbiology, physical-chemical and sensorial analysis were made in order to verify the influence of the chilling system and the effect of different modified atmosphere packaging in meat preservation, at different storage times. The results shown that the type of refrigeration system does not affect the quality of meat significantly, but the use of both different modified atmospheres in the packaging process has a great influence in meat shelf life extension. The use of low O2 atmospheres has an antimicrobial effect, postponing the microbiology deterioration of the meat. On the other hand, the use of high oxygen atmospheres promotes visual organoleptic properties, which are essential in consumer's choice.

Ce travail de Thèse concerne l’évaluation de la qualité d’une jonction entre deux plaques d’épaisseurs identiques mais de matériaux différents. Il s’agit d’étudier la réflexion et la transmission d’une onde de Lamb à travers cette jonction. Différents cas ont été étudiés, jonction avec défaut débouchant ou non, jonction droite ou biseauté. Les coefficients de réflexion et de transmission théoriques des ondes de Lamb sur la jonction sont obtenus par une approche multi-modale basée sur l’exploitation de la relation d’orthogonalité entre les différents modes. La méthode des éléments finis (MEF) est ensuite utilisée, elle permet de déterminer les limites d’application du modèle théorique proposé. Pour finir, une étude expérimentale est effectuée, elle met en évidence des effets de diffraction non pris en compte dans les modèles théoriques et numériques à deux dimensions
This work deals with the evaluation of the junction of two plates by means of ultrasonic guided waves. The plates are edge to edge welded and are made of different materials. The reflection and transmission of guided Lamb wave on this junction is studied. Different junctions are considered: straight or bevelled, with surface or internal defect. The theoretical coefficients of reflection and transmission are obtained by a multi-modal approach based on the orthogonality relation between the Lamb modes. The Finite Element Method (FEM) is used and allows determining the limits of the theoretical model. Finally, an experimental study is performed. It highlights the effects of diffraction that have not been taken into account in the two dimensional theoretical and numerical models

The aim of this study was to investigate the effect of feeding cotton co-products with different gossypol concentrations on reproductive development of lambs close to puberty and also on carcass traits and fatty acid profile of meat. Twenty four 5-months old ram lambs (20.6 ± 1.9 kg BW) were used. These were housed in individual pens and received four diets: 20% of dry matter intake (DMI) of whole cottonseed (WCS), 20%DMI of cottonseed meal (CSM), 20%DMI of high oil cottonseed meal (CSC) and a control group without cottonseed co-products (CTL). Free gossypol intake was 0, 16.32, 6.98 and 5.47 mg/kgBW for CTL, WCS, CSC and CSM, respectively. At each 15 days, the animals were weighted, and blood and semen samples were collected. Sperm motility, vigor, mass movement, concentration and pathologies were evaluated. The free testosterone and cortisol concentrations in serum were determined. After 95 experimental days, the lambs were slaughtered and carcass traits were measured. Meat samples of Longissumus dorsi muscle were taken for fatty acid profile analysis. And testis samples were collected to analysis in light and transmission electron microscopes. The treatments did not differ in average daily weight gain, sperm volume, motility, vigor and concentration. The CTL group had higher testosterone concentration than CSC at the end of trial and had lower total sperm defects and higher mass movement than others. The number of mitochondrial sheath aplasia increased with increasing gossypol level in diet. There was no relation between the other variables evaluated and gossypol level in diets; however the groups that received cottonseed co-products showed worse reproductive parameters than CTL. Therefore, these co-products had negative impact on reproductive system of puberal lambs. In relation to fatty acid profile, meat from CSM and CSC groups had higher levels of conjugated linolenic acid (CLA) than others and yet CSC group showed higher vaccenic acid than others. Meat from animals that received whole cottonseed had less unsaturated fatty acids, CLA and vaccenic acid. Therefore, between cotton co-products, the processed (CSM and CSC) must be preferred for use in ruminant feed rather than whole cottonseed. The meat from animals that did not receive cotton co-products had higher n-3 fatty acid, and also better n-6 to n-3 ratio compared to others. This can impair the use of these co-products due to current great importance given to these fatty acids in human nutrition
Com este estudo, objetivou-se avaliar o efeito da alimentação com co-produtos do algodão tendo diferentes concentrações de gossipol no desenvolvimento reprodutivo de cordeiros no período próximo a puberdade e também nas características de carcaça e no perfil de ácidos graxos da carne. Vinte e quatro cordeiros com 5 meses de idade (20.6 ± 1.9 kg PV) foram utilizados. Estes foram alojados em baias individuais e receberam quatro dietas: 20% da ingestão de matéria seca (IMS) de caroço de algodão (CAROÇO), 20%IMS de farelo de algodão (FARELO), 20%IMS de torta de algodão (TORTA) e um grupo controle (CONTROLE) sem o uso de co-produtos do algodão. A ingestão de gossipol livre foi de 0, 16,32, 6,98 e 5,47 mg/kgPV para CONTROLE, CAROÇO, TORTA e FARELO, respectivamente. A cada 15 dias, os animais foram pesados, e amostras de sangue e sêmen foram coletadas. O sêmen foi analisado quanto a motilidade, vigor, turbilhão, concentração e patologias. Foram determinadas a concentração de testosterona livre e cortisol no soro sanguíneo. Após 95 dias de experimento, os cordeiros foram abatidos e as características de rendimento de carcaça e composição da 12ª costela foram mensuradas. Amostras do músculo Longissumus dorsi foram coletadas para a análise do perfil de ácidos graxos. Amostras dos testículos foram coletadas para análise em microscopia de luz e microscopia eletrônica de transmissão. Os tratamentos não diferiram em ganho em peso diário, volume ejaculado, motilidade, vigor e concentração espermática. Os animais do grupo CONTROLE apresentaram concentração de testosterona maior que os do grupo TORTA no final do período experimental. E ainda os animais do grupo CONTROLE tiveram menor número de defeitos totais e maior turbilhão que os outros. O número de lesões de aplasia da bainha mitocondrial aumentou com o aumento do teor de gossipol livre na dieta. Para as outras variáveis avaliadas, não houve relação com o nível de gossipol livre na dieta, no entanto os animais que receberam co-produtos do algodão apresentaram piores parâmetros reprodutivos do que os animais do grupo CONTROLE. Por isso, pode-se concluir que estes co-produtos tiveram um impacto negativo no sistema reprodutivo dos cordeiros durante a puberdade. Em relação ao perfil de ácidos graxos, a carne dos animais dos grupos TORTA e FARELO apresentaram maiores valores de ácido linolênico conjugado (CLA) que os outros dois tratamentos e ainda os animais do grupo TORTA apresentaram maior teor de ácido vacênico que os outros. A carne dos animais que receberam caroço de algodão mostrou menor quantidade de ácidos graxos insaturados, CLA e ácido vacênico. Portanto, dentre os co-produtos do algodão, os processados (FARELO e TORTA) devem ser preferidos para uso na nutrição de ruminantes em detrimento ao caroço. A carne dos animais do grupo CONTROLE apresentou maior teor de n-3, e ainda melhor proporção entre n-6 e n-3 comparado com as demais dietas, o que pode dificultar o uso desses co-produtos devido a grande importância dada atualmente a este grupo de ácidos graxos na nutrição humana

My students are, for the most part, potentially very good writers. However, when I get these students, their lab report writing skills are quite limited, and therefore, are very poor. Focus for doing labs thus far in their science career has been how well they can perform the lab from verbal instructions not written instructions. The students have a difficult time reading and understanding what the protocol wants them to do, and they have an even more difficult time explaining what they performed during the lab activity in a lab report. This project investigated how well the students discussed their course of action after performing the lab activity in a written report. The students were given written lab protocols and were expected to follow the procedure and make observations along the way. The labs were all completed in one 45 minute class period. The students were then given one day in class to work on their lab report following the lab report rubric (Appendix A). Data collection for this project not only included lab report writing, but what the students' comfort levels were in different elements of the lab, how well they reviewed their own work, how well they reviewed other peer's work, and how they felt about the whole lab report writing process throughout the year. Several teachers were also asked to evaluate how well these particular students processed and followed directions in their classrooms as well. The resulted indicated that by implementing a peer review session into the lab report writing process the report score significantly improved. The students who struggled at the beginning of the process were now completing quality lab reports in half the time and the peer review rubrics were being scored with the highest marks. Because of these positive outcomes, I know that peer review is an integral part of the learning process to produce quality lab reports and I will continue to conduct this practice in my classroom in years to come.

Abstract Sheep fat contains relatively high levels of saturated fatty acids while poly-unsaturated fatty acids (PUFA) are toxic to cellulolytic bacteria and are also saturated in the rumen. Stabilization of residual oil in sunflower oilcake by conversion into calcium salts would be advantageous. Alpha lipoic acid acts as an anti-oxidant to ameliorate the effects of oxidative stress caused by high dietary levels of PUFA. Residual oil (14%) in mechanically extracted (expeller) sunflower oilcake (SFOC) was saponified in situ and compared in a complete feedlot diet (100 g crude protein and 31 g extractable fat/kg feed) with commercially extracted oilcake containing 2.4% residual oil (control diet with 29 g fat and 123 g crude protein kg feed) fed to four groups of 10 SA Mutton Merino weaner lambs (ca. 23 kg) for nine weeks. Both diets were fed either with, or without a weekly oral dosing of 500 mg α-lipoic acid. Fatty acid composition was determined on back fat samples while thiobarbituric acid-reactive substances (TBARS) were determined on samples of m. longissimus dorsi stored for zero and six months and displayed for six days. The back fat of the lambs on the saponified expeller SFOC diets contained significantly higher levels of saturated fatty acids and lower levels of mono-unsaturated fatty acids. PUFA were unaffected. High TBARS levels (>1.0) were found after six months storage. Non significant increases in TBARS were observed in the groups that received lipoic acid.

L’impact de facteurs abiotiques (pluviométrie, humidité relative, température, type de sol, altitude) et propres à la plante (maturité des feuilles, stade phénologique) sur la composition nutritionnelle et chimique de poudres de feuille de MOL a été étudié. Pour cela, différentes techniques spectroscopiques (PIR, MIR, RMN 13C) couplées à la chimiométrie (ACP, AComDim) ont été utilisées. L’échantillonnage a été réalisé entre 2015 et 2017 dans 5 zones agroclimatiques du Cameroun. Les traitements des empreintes des sols dans l’IR montrent que la répartition des échantillons est similaire au découpage des zones agroclimatiques du Cameroun et que la spectroscopie est une technique qui permet de prédire efficacement l’appartenance de ces sols à une classe. L’étude des données climatiques montre que les données moyennées sur une période de 6 mois peuvent représenter les zones agroclimatiques. L’analyse des empreintes spectrales des poudres de feuille a révélé que leur composition en métabolites primaires et en nutriments est dépendante de la zone agroclimatique de collecte et du stade de maturité de la feuille. Du point de vue de la qualité sanitaire, la construction expérimentale d'isothermes de sorption à 20, 30 et 40°C a permis de montrer que le comportement des poudres de feuille vis-à-vis de la disponibilité en eau n’est pas affecté par la température. Les modèles PLS construits à partir des spectres PIR des poudres de feuille ont permis de prédire efficacement leur teneur en eau, en minéraux et protéines. D’autre part, pour s’assurer de la conformité de ces compléments alimentaires des modèles PLS d’adultération des feuilles par les tiges ont été établis
The impact of abiotic factors (rainfall, relative humidity, temperature, soil type, topography), leaf maturity and plant phenological stage on MOL leaves nutritional and chemical composition was studied. Spectroscopic methods (near and mid infrared (NIR and MIR), solid-state nuclear magnetic resonance (13C NMR) coupled with chemometrics (principal components analysis (PCA), anova common dimensions (AComDim) were used to differentiate 98 leaf powder samples collected between 2015 and 2017 in 5 agroclimatic regions of Cameroon. Those techniques were also used to map samples of cameroonian soils using their IR fingerprints and to predict their class (ferralitic, halomorphic, hydromorphic). This approach has allowed to assess the impact of the agroclimatic zone (climate, soil) and that of the maturity stage of the leaves on the primary metabolites and nutrients content of MOL leaves. Their collects can therefore be catered to specific nutritional needs.Regarding the sanitary quality, experimental construction of sorption isotherms at 20, 30 and 40 °C has shown that a temperature variation of the drying process will not affect MOL leaf powders available water content. Furthermore, a rapid methodology was developed to simultaneously predict water content and activity values (aw) of MOL leaf powders using NIR signatures and experimental sorption isotherms. A PLS2 was obtained with low standard errors of prediction. Protein and selected minerals (Ca, Fe, K) contents were also predicted from PLS1 models with low standard error of prediction. Those approaches have allowed to bring a contribution to the improvement of MOL leaf powders safety, quality control and traceability

Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The aim of the study was to determine the effect of increasing levels of Maize silage in finishing diets for Merino lambs on their feed intake, production performance, feed conversion ratio, digestibility and meat quality. Concerns exist regarding the intake of high moisture and fibre containing silage in sheep due to the physical fill effect thereof. To determine the efficiency of silage as feed ingredient for sheep, maize was cut at 27% dry matter (DM), compacted into 220 litre plastic drums, sealed and left to ferment for 60 days. The silage produced was analysed for fermentation end products and the nutritive value determined. The silage produced had an optimum pH, starch and water soluble carbohydrate (WSC) content. The crude protein (CP) content (112.2 g/kg DM) was higher than expected. Four diets containing, on a dry matter (DM) basis either, 0, 20, 50 or 70% maize silage was formulated on an iso-nutrient basis with exception of neutral detergent fibre (NDF). The aim was to establish the effect of increasing levels of silage on animal production with regard to dry matter intake, growth, digestibility and meat quality. Diets were formulated on an iso-nutrient basis to match the 70% silage diet and therefore had relatively low specifications due to the high inclusion of silage from the 70% silage diet. A growth study and an in vivo and in vitro digestibility study were conducted to determine the effect of the different diets on feedlot sheep production. Meat quality was also determined to establish whether the experimental diets had an effect on meat quality. Forty lambs in a completely randomised block design, with four treatments, were used in a 60-day finishing study. The dry matter intake (DMI) of lambs decreased as silage inclusion increased above the 20% silage inclusion level. At the 20% inclusion rate, the feed intake of the animals was stimulated. This resulted in significant differences found between the cumulative intake of the low and the high silage diets. Feed conversion ratio (FCR) was poorer, however, for the control and 20% silage diets. The poor FCR most likely was related to the quality of the feed ingredients used in the formulation of the control feed and the concentrate in the 20% silage diet rather than the silage itself. Significant differences were also found in the dressing percentage of the slaughtered animals where the 20 and 50% silage diets had a higher dressing percentage than the control and 70% silage diets. It was concluded that silage can be successfully incorporated into sheep diets, especially at low levels where its inclusion stimulates intake. Eight animals per group were used in an in vivo digestibility study to determine the apparent digestibility of the experimental diets. Feed, faeces and urine samples collected during the trial period were analysed for the respective nutrients. The 20% diet, even though having the best overall apparent digestibility, did not result in better production responses. Lambs on the 20% silage diet had the highest daily DM intake, which resulted in them having the highest energy intake. There were no differences in total energy excreted between the silage-based diets. This resulted in the 20% silage diet also having the best energy retention. Nitrogen retention was the highest for the control and 20% silage diets. This can be ascribed to the low quality of the concentrate part of the diet. The 20% silage diet, as previously stated, had the highest apparent DM and organic matter (OM) digestibility, while the control diet showed the lowest overall nutrient digestibility. The low nutrient digestibility of the control diet can be ascribed to the relatively poor quality ingredients used. There were no differences in the crude protein (CP) digestibility between the control and the 20% diet. Both proved to be higher than the CP digestibility of the 50 and 70% silage diet. As the neutral detergent insoluble nitrogen (NDIN) was higher for the 50 and 70% diets, this observation was not surprising. Fibre content of the silage-based diets increased as the inclusion level of the silage increased, which resulted in a decrease in overall fibre digestion. Three cannulated sheep were adapted on each experimental diet for two weeks before rumen fluid was collected for the in vitro digestibility study. No differences between the silage based diets were found for in vitro true digestibility (IVTD). The IVTD of the 20, 50 and 70% diets were higher, however, than the IVTD of the control diet confirming earlier observations on the choice of ingredients used in the control diet to formulate iso-nutrient diets. Degradability coefficients were determined for the DM and NDF fractions of the different experimental diets and fitted to the non-linear model; p = a + b (1 – e-ct). The amount of DM that disappeared in a certain time (t) is represented by p. Constant a represents the fraction that was rapidly soluble, b represents the potential degradable fraction and c is the rate at which b was degraded. There were no differences between experimental diets for the rapidly soluble fraction. The silage-based diets had a higher potential degradable fraction (b) but did not differ in the degradability rate (c) from the control diet. Silage-based diets had higher overall effective degradability than the control but did not differ between one another. Constant a was not determined for NDF degradability since the NDF fraction did not have a rapidly soluble fraction. The control diet had the lowest potential degradable NDF fraction with the rate also being lower than the silage based diets. Effective NDF degradability was highest for the 50% silage diet. Lambs used in the finishing study were slaughtered and meat samples taken for meat quality tests. The pH, colour, drip loss, cooking loss, shear force and fatty acid composition were determined on the Longissimus dorsi samples collected at Roelcor (Malmesbury, Western Cape, South Africa). Proximate analysis was also conducted on the meat samples. The experimental diets did not have a significant effect on the proximate chemical composition of the meat. Colour differences were found; however no clear pattern could be established. There were no differences in fatty acid composition. It can be concluded that up to 70% maize silage can be included in the finishing diets of Merino lambs with no adverse effects on the meat quality. The study showed that 20% maize silage can be included in the finishing diets of Merino lambs without negatively affecting intake, production, digestibility or meat quality. Future research is needed to optimise the 20% silage diet, however, and to again look at the effect that it will have on animal production, including the effect thereof on total methane emissions.
AFRIKAANSE OPSOMMING: Die doel van die studie was om te bepaal of mielie kuilvoer doeltreffend gebruik kan word as ‘n komponent in die afronding van Merino lammers. Gedurende die proses is mielies gesny teen 27% droë materiaal (DM), en saamgepers in 220 liter plastiek dromme. Dit is toegelaat om te fermenter vir 60 dae. Die kuilvoer wat daaruit geproduseer is, is geanaliseer vir fermentasie eindprodukte, en die voedingstofwaarde is bepaal. Vier diëte met onderskeidelik 0 (kontrole), 20, 50 en 70% kuilvoer is geformuleer op ‘n iso-nutriëntbasis met die uitsondering van vesel (NDF). ‘n Groeistudie, tesame met ‘n in vivo en in vitro verteerbaarheidstudie is uitgevoer om die effek van die verskillende diëte op diere produksie te toets. Vleiskwaliteit toetse is ook gedoen om te kyk of die verskillende diëte ‘n effek op vleiskwaliteit het. Veertig lammers, in ‘n ewekeurige blokontwerp, is gebruik in ‘n 60 dae afrondingstudie. Dit is opgemerk dat die DM inname (DMI) afgeneem het soos die kuilvoer insluiting bo die 20% vlak toegneem het. By die 20% insluitingskoers, is voerinname by die diere gestimuleer. Dit het veroorsaak dat beduidende verskille gevind is tussen die kumulatiewe inname van die lae en die hoë kuilvoer diëte. Die voeromsetkoers (VOK) was egter hoër vir die kontrole en 20% kuilvoer diëte. Beduidende verskille is ook gevind in die uitslagpersentasie van die diere, waar die 20% en 50% kuilvoer diëte ‘n hoër uitslagpersentasie as die kontrole en 70% kuilvoer diëte gehad het. Agt diere is per groep gebruik in ‘n in vivo verteerbaarheidstudie om die skynbare verteerbaarheid van die eksperimentele diëte te toets. Voer, feses en urien monsters is gedurende die proefperiode ingesamel en geanaliseer. Die 20% kuilvoer dieet het die hoogste DM en organiese materiaal skynbare verteerbaarheid teenoor die kontrole diet wat die laagste gehad het. Daar was geen verskille in die ru- proteien (RP) verteerbaarheid van die kontrole en 20% kuilvoer diet nie. Beide was hoër as die RP verteerbaarheid van die 50% en 70% kuilvoer dieet. Die veselinhoud van die kuilvoergebasseerde diëte het toegeneem soos die insluitingsvlak van die kuilvoer toegeneem het, wat ‘n afname in veselvertering veroorsaak het. Lammers op die 20% kuilvoer dieet het die hoogste daaglikse DM inname gehad, wat die hoogste energie inname tot gevolg gehad het. Daar was geen verskille in die totale energie inname van die kuilvoergebasseerde diëte – dit het veroorsaak dat die 20% kuilvoer dieet ook die beste energie retensie gehad het. Stikstof retensie was die hoogste vir die kontrole en 20% kuilvoer dieet. Drie gekannuleerde skape is vir twee weke op elke eksperimentele dieet aangepas voordat rumenvloeistof ingesamel is vir die in vitro verteerbaarheidstudie. Geen verskille is gevind vir die in vitro ware verteerbaarheid (IVWV) tussen die kuilvoergebasseerde diëte nie. Hulle was egter hoër as die IVWV van die kontrole dieet. Degradeerbaarheid koëffisiënte is bepaal vir die DM en NDF fraksies van die verskillende eksperimentele diëte en is gepas in die model p = a + b (1 – e-ct). Die hoeveelheid DM wat verdwyn het binne ‘n sekere tyd (t) word voorgestel deur p. Die konstante a verteenwoordig die fraksie wat vinnig oplosbaar is, b verteenwoordig die potensieel degradeerbare fraksie en c is die koers waarteen b gedegradeer is. Konstante a is nie bepaal vir die NDF degradeerbaarheid nie, aangesien die NDF fraksie nie ‘n vinnig oplosbare fraksie gehad het nie. Daar was geen verskille in die vinnig oplosbare fraksie tussen eksperimentele diete nie. Kuilvoer gebasseerde diete het ‘n hoër potensieel degradeerbare fraksie gehad, maar daar was geen verskille in koers van degradering nie. Die kuilvoergebasseerde diëte het ‘n hoër DM effektiewe degradeerbaarheid as die kontrole dieet. Effektiewe NDF degradeerbaarheid was die hoogste vir die 50% kuilvoer dieet. Lammers in die studie gebruik is geslag en vleismonsters is geneem vir vleiskwaliteit toetse, insluitende pH, kleur, drupverlies, kookverlies en taaiheid. Proksimale analise is ook uitgevoer op die vleismonsters. Die eksperimentele diëte het nie ‘n beduidende effek op die proksimale chemiese samestelling van die vleis gehad nie. Kleur verskille is wel gevind, maar geen duidelike patroon kon vasgestel word nie. Daar was geen verskille in die vetsuur samestelling nie. Daar kan dus tot die gevolgtrekking gekom word dat mielie kuilvoer ingesluit kan word in die afrondingsdiëte van Merino lammers, tot by 70%, sonder enige negatiewe effekte op die vleiskwaliteit. Daar is tot die gevolgtrekking gekom dat mielie kuilvoer suksesvol geïnkorporeer kan word in skaapdiëte, veral teen lae vlakke (20%) waar die gebruik nie net inname stimuleer nie, maar ook geen negatiewe effekte het op produksie en verteerbaarheid nie.
Dr. Francois van de Vyver, Cape Wools and NWGA for providing funding in the form of post graduate bursaries

Quality control is a necessity when it comes to automating a biological lab with the help of robotics. Two major quality control objectives are targeted by the research group PharmBio at Uppsala University: (1) barcode recognition and decoding, and (2) determining the position and orientation of microplates relative the gripper at the end of an industrial robot arm. In order to achieve these objectives, a hardware package with a camera and microcomputer has been designed and built, which can be attached next to the gripper. In addition to the hardware solution, a software stack has been developed and implemented which utilizes the camera and microcomputer to capture digital images. These images are enhanced and processed using machine vision software on the microcomputer, after which the final generated data is sent to an external system for further handling. The final system consisting of integrated hardware and software is capable of achieving both goals: barcode recognition and plate pose determination. However, due to changes in the group’s project plan during the current Master’s project, final implementation of the plate pose determination software remains as future work for a later version.
Kvalitetskontroll är en nödvändighet när det gäller automatiseringen av ett biologiskt lab med hjälp av robotik. Forskargruppen PharmBio vid Uppsala universitet har två huvudsakliga mål gällande kvalitetskontroll: (1) igenkänning och avläsning av streckkoder, och (2) fastställandet av position och riktning av en mikrotiterplatta relativt en gripklo på änden av en robotarm. För att uppnå dessa mål har en enhet innehållandes en kamera och enkortsdator designats och byggts, tänkt att fästas intill gripklon. Utöver denna enhet har ett mjukvarusystem som använder kameran och datorn för att ta bilder utvecklats och implementerats. Dessa bilder behandlas med hjälp av machine vision-mjukvara på enkortsdatorn innan framtagen data skickas vidare till ett externt datorsystem för ytterligare hantering. Det slutgiltiga systemet bestående av integrerad hård- och mjukvara är kapabel att uppnå båda projektmål: streckkodsavläsning och avgöra position/riktning hos en mikrotiterplatta. På grund av ändrad planering hos forskargruppen under arbetets gång kommer dock implementation av mjukvaran framtagen för positions- och riktningsigenkänning dröja till en senare version av projektet.

The importance of protein quality in the formulation of ruminant rations has been regarded as inconsequential in the past. Moreover, the use of agro-industrial by-products as feed ingredients have become attractive alternatives in the animal feed industry, whereby several of these products characteristically have alternative protein qualities. Dried brewer’s grains (DBG) is a by-product originating from the beer manufacturing industry, frequently incorporated in the diets of feedlot lambs, however, has caused obstacles in some feed mills in South Africa. The oilseed by-products: canola-, soybean- and cottonseed meal, have all been proposed as suitable protein sources which can be included lamb feedlot diets. In this study, DBG, canola meal, soybean meal and cottonseed meal were incorporated as protein sources into concentrate-rich feedlot lamb diets. All experimental diets were formulated to contain 14% crude protein (CP) and 10.2 MJ ME/kgDM. The four experimental treatments differed in terms of the inclusion of the primary protein source which was either DBG, canola meal, soybean meal or cottonseed meal. Two experiments were conducted. The first experiment, comprising a feedlot growth experiment, utilized a randomised complete block design (RCB) as the experimental design. It was conducted using 200 Dӧhne-Merino lambs in order to investigate the effect of protein quality on the growth performance, feed intake and carcass parameters. The average total weight gained over the duration of the feedlot growth trial, as well as the average daily gain (ADG) of the canola meal treatment, was lower (P<0.05) than the other three treatments. Higher (P<0.05) feed intakes were realised on the cottonseed meal diet as opposed to the other three treatments. Additionally, lower (P<0.05) feed intakes were realised on the DBG diet when compared to the other three treatments. The feed iv conversion ratio (FCR) of the DBG diet was better (P<0.05) than the canola-, soybean- and cottonseed meal treatments, respectively. Conversely, the FCR realised for the canola meal diet was poorer (P<0.05) than the other three treatments. The lower (P<0.05) final live weights of the lambs from the DBG treatment, in comparison to those from the canola meal and cottonseed meal treatments, translated into lower (P<0.05) hot and cold carcass mass. Carcass classification remained unaffected (P>0.05) by treatment. Nevertheless, dissimilarities (P<0.10) were detected in the dressing percentages of the canola meal treatment and cottonseed meal treatment, whereby the dressing percentages of the former were higher. The second experiment entailed four mature cannulated wethers being subjected to a 4×4 Latin square design in order to investigate the effect of protein quality on the intake, apparent total tract digestibility, degradability and some rumen fermentation parameters of the sheep. Feed intake was greater (P<0.05) for the DBG diet as opposed to the soybean meal diet. Thus, the feed intake results of the two separate experiments differed from one another. The apparent DM digestibility of the DBG diet was lower (P<0.10) than the soybean meal diet. A higher (P<0.05) apparent CP digestibility was realised on the soybean meal diet, as opposed to the DBG and canola meal diets. The apparent total tract starch and NDF digestibility remained unaffected (P>0.05) by treatment for the current study. A lower dry matter (DM) degradability estimate (P<0.05) was realised for DBG, when compared to the other three treatments. No differences (P>0.05) were detected in the CP degradability estimates between the four respective protein concentrates, however could have been predisposed to experimental error. Average ruminal pH was higher (P<0.05) for the cottonseed meal diet, as opposed to the other three treatments and average ruminal ammonia nitrogen concentration did not differ (P>0.05) between treatments. The results advocate that protein quality has the potential to influence growth parameters, digestibility and rumen fermentation in sheep. Further research needs to be conducted on the inclusion levels of the respective protein concentrates and the breakpoint in the feeding period, where protein quality can be regarded as not important anymore.
Dissertation (MSc (Agric))--University of Pretoria, 2020.
Animal and Wildlife Sciences
MSc (Agric)
Unrestricted

The main objective of the study was to determine the effects of enzymes on quality of breads baked in halogen lamp-microwave combination, microwave and conventional oven. It was also aimed to determine the optimum processing conditions in these ovens. In the first part of the study, as independent variables, baking time, baking temperature for conventional oven
microwave power for microwave oven and microwave power and halogen power for combination oven was used. Weight loss, specific volume, firmness and color of the breads were measured during the study. The optimum baking conditions were determined as 13 min at 200°
C in conventional oven, 0.75 min at 100% power in microwave oven, 10 min at 60% power in halogen lamp oven, and 3 min at 30% microwave power and 70% halogen lamp power in halogen lamp-microwave combination oven. In the case of combination oven, specific volume and color values of breads were comparable with the conventionally baked breads but weight loss and firmness of them were still higher. The effects of different enzymes (&
#945
-amylase, xylanase, lipase &
protease) were studied to reduce the quality problems of breads baked in microwave and halogen lamp-microwave combination oven. The optimum baking conditions determined for each type of oven in the first part of the study were used in the investigation of the functions of enzymes on bread quality during baking and staling. As a control, no enzyme added breads baked at 200°
C for 13 min in conventional oven were used. All the enzymes were found to be effective in reducing initial firmness and increasing specific volume of breads baked in microwave and halogen lamp-microwave combination ovens. However, in conventional baking, the effects of enzymes on crumb firmness were seen mostly during storage. The usage of enzyme protease in the bread formulation resulted in breads with higher volume and darker color in all of the ovens. All of the enzymes were found to be effective to retard the staling of breads baked in conventional, microwave and halogen lamp-microwave combination ovens.

Accompanied by the fast development of technology and channels in the advertisement industry, many traditional incumbents felt pressure and were seeking ways to change or better their own position within the industry. The Nordic Association of Heatset Printer (NAHP), where this thesis was carried out, is largely associated with these traditional channels for advertising, such like newspapers, brochures and magazines. They are taking their initiative to prepare and face the challenge coming from new entrants within the advertising industry. I have identified that to fulfill the responsibilities to their customers at a very high standard could enable themselves to continuingly remain a competitive position in the advertisement industry, and among these responsibilities, the printing quality is definitely an important one. By checking whether all the printers conform to the error tolerances set by the ISO standard, I could offer the members of the organization useful information and suggestion, and eventually give them directions on where they might need to improve, and where they need to maintain. I have also identified 3 determinants regarding printing and they are print density, dot gain and the ΔE of L*a*b*. Checking whether those three primaries have met the industry standard has become the main job of this thesis work. To finish this thesis work, I have gathered samples from printers within NAHP, tested the color control strips on each samples, input the data into statistical Excel files, programmed to analyze the data, and finally conducted evaluations. The test results have revealed that most presses from the printing houses within my thesis work are able to offer high quality prints. However, certain problems have also been identified. Some presses definitely need to change and improve their printing setting in order to reach ISO standard and achieve audience satisfaction. In addition, the results have also double confirmed that all three investigated properties, print density, dot gain and ΔE of L*a*b*, correlate intensely and influence one and another.

Thesis (MSc Food Sc (Food Science))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: The aim of this study was to investigate the impact of an extensive (free-range) and intensive (feedlot) production system on the consumer’s intrinsic preference cues (physical attributes, chemical composition, fatty acid profile, aroma, flavour, initial juiciness, sustained juiciness, first bite, residue, instrumental tenderness) for three muscles (Biceps femoris, Longissimus dorsi, Semimembranosus) of Dohne Merino lambs (8 months). Secondly to investigate the effect of natural exercise (grazing, extensive production systems) or restrictive movement (intensive production systems), on the muscle fiber type composition of the same lamb muscles and the subsequent effect on the meat quality characteristics. Intensively raised lambs produced carcasses with a significantly higher dressing percentage, thicker subcutaneous fat layer (13th rib and 3rd/4th lumbar vertebra) and a greater fat ratio (carcass composition). Meat of intensively raised lambs had a higher (p < 0.050) Homo-glinolenic (C20:3n6), Eicosapentaenoic (C20:5n3), Docosapentaenoic acid (C22:5n3) content and n3:n6 ratio. Extensively reared lambs had a higher (p < 0.050) slaughter weight, cold carcass weight and the meat of these lambs had a higher myoglobin content. Results of this study indicate that intensively reared lambs produced meat with more favourable sensory characteristics compared to the extensive production system as well as a significant increase in sensory tenderness for Biceps femoris muscle. Overall the Biceps femoris muscle was the muscle that was primarily affected by the treatment (production systems). The Biceps femoris from intensively raised lambs contained significantly more intramuscular fat and type IIB muscle fibers whereas the Bicpes femoris of the lambs from the extensive production system contained more (p < 0.050) insoluble collagen and type I muscle fibers. During texture profile analysis (instrumental tenderness test) the Longissimus dorsi and Semimembranosus of extensively raised lambs required a higher (p < 0.050) compression force during the first cycle of compression, indicating that these muscles are tougher. The results of this study provided valuable insight into the impact of production systems on lamb meat quality and that the application of intensive production systems will increase the sensory characteristics of the selected muscles from Dohne Merino lambs, especially the tenderness of the Biceps femoris, which has a high retail value. On the other hand health conscious consumers will prefer extensively produced meat due to the favourable n3:n6 ratio, intramuscular fat content and the presences of less visible fat (subcutaneous).
AFRIKAANSE OPSOMMING: Hierdie studie was tweedoelig en is uitgevoer op die Biceps femoris, Longissimus dorsi en Semimembranosus spiere van Dohne Merino lammers (8 maande oud). Die eerste doel van die studie was om te bepaal wat die effek van ‘n ekstensiewe (weiding) en intensiewe produksie sisteem sal wees op vleis verbruikers se algemene kwaliteit voorkeure (fisiese eienskappe, chemiese samestelling, vetsuur profile, aroma, smaak, sappigheid, taaiheid,). Tweedens om te bepaal tot watse mate natuurlike oefening, verkry deur weiding asook beperkte beweging as gevolg van voerkraal omstandighede, die spier vesel tipe samestelling sal verander en die direkte impak van die samestelling op kwaliteit eienskappe van vleis. Lammers van die intensiewe produksie sisteem het ‘n betekenisvolle verhoging in uitslagpersentasie, onderhuidse vet dikte (13de rib en 3de/4de lende werwel) en vet ratio (karkas samestelling) getoon. Die vleis van die lammers het meer (p < 0.050) C20:3n6, C20:5n3 en C22:5n3 vetsure bevat asook ‘n hoër n3:n6 ratio gehad. Lammers van die ekstensiewe produksie sisteem het ‘n betekenisvolle hoër slag en koue karkas gewig gehad. Die vleis van die lammers het meer (p < 0.050) mioglobien bevat as intensiewe lammers. Resultate van die studie dui aan dat die vleis van lammer van die intensiewe produksie sisteem meer gunstige sensories karakteristiek produseer in vergelyking met lammers van die ekstensiewe produksie sisteem, asook ‘n betekenisvolle verhoging in sensoriese sagtheid van die Biceps femoris spier. Die Biceps femoris was die spier in die studie wat die meeste geaffekteer was deur die behandeling (produksie sisteme). Die Biceps femoris spier van intensiewe lammers het meer intramuskulêre vet en tipe IIB spier vesels bevat teenoor die Biceps femoris van ekstensiewe lammers wat meer onoplosbare kollageen en tipe I spier vesels bevat het. Gedurende die tekstuur profiel analise (instrumentele sagtheid toets) het die Longissimus dorsi en Semimembranosus van ekstensiewe lammers a hoër kompressie krag vereis, wat aandui dat die spiere taaier is as die ooreenstemmende spiere van intensiewe lammers. Die resultate van die studie voorsien ons met waardevolle insig in die inpak van verskeie produksie sisteme op die kwaliteit van lams vleis. Die afleiding kan gemaak word dat die implementering van intensiewe produksie sisteem die sensoriese kwaliteit van die spiere van Dohne Merino lammers verbeter, veral die sagtheid van die Biceps femoris spier, wat ‘n hoë kommersiële waarde het. Laastens, gesondheidsbewus verbruikers sal verkies om vleis te koop van ekstensiewe lammers weens die gunstige n3:n6 ratio, spier vetinhoud en die minder sigbare vet (onderhuidse vet) op die vleis.

Two studies were conducted to compare nitrogen (N) and glutamate metabolism in Polypay and percentage White Dorper lambs.First, a two-phase digestion/N metabolism trial was conducted with 18 wether lambs of three genetic types: Polypay (PP), 1/2 White Dorper 1/2 Polypay (1/2 D), and 3/4 White Dorper 1/4 Polypay (3/4 D). Six lambs of each genetic type were fed a high roughage diet (HR; Phase 1) or high concentrate diet (HC; Phase 2). DM and N digestion was higher for 1/2 D than PP or 3/4 D fed HC. N retention was highest for 1/2 D regardless of diet.The second study analyzed the effect of genetic type on glutamate transporter and metabolizing enzyme expression in liver, kidney, longissimus dorsi muscle (LD muscle), and subcutaneous fat (Sub Q Fat) tissue of 18 wether lambs of three genetic types: PP, 1/2 D, and 15 /16 White Dorper 1/16 Polypay (15 /16 D). Tissue samples were analyzed for protein and mRNA content of GS, GDH, ALT, EAAC1, and GLT-1. Glutamate transport and metabolism capacity was lowest for the heavier muscled 15 /16 D lambs.The results suggest genetic type has an effect on N metabolism due to differential expression of glutamate transporters and metabolizing enzymes.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A indústria têxtil é responsável pela geração de efluentes que, normalmente, apresentam um nível indesejável de coloração devido à etapa de tingimento, onde utilizam-se corantes que, quando lançados nos corpos d'água, levam à alteração de sua qualidade e ocasionam efeitos danosos ao meio ambiente e à saúde humana. Em vista disso, este trabalho teve como objetivo utilizar a lama vermelha, resíduo gerado em larga escala na produção de alumínio, como meio adsorvedor do corante Reativo Blue 19, o qual possui grande aplicação industrial e características que dificultam sua remoção em solução aquosa por meio de tratamentos convencionais. Sendo assim, optou-se por ativar a lama vermelha através de tratamento químico (água do mar, nitrato de cálcio e peróxido de hidrogênio) e térmico (400ºC e 500ºC), visando identificar a interferência desses tratamentos no aumento de sua capacidade adsortiva. Para isso, foi realizada a caracterização das amostras de lama vermelha através da determinação do pH, condutividade elétrica, ponto de carga zero (PCZ) difração de raios - x (DRX) e área superficial específica, sendo que a análise granulométrica foi realizada somente para a lama vermelha in natura. Em seguida, visando determinar a capacidade adsortiva da lama vermelha ativada, foram construídas isortermas de adsorção, linearizadas segundo os modelos de Langmuir e Freundlich. Para efeito de comparação, a mesma metodologia foi aplicada ao carvão ativado visando determinar sua capacidade em adsorver o mesmo corante. Foi realizado o estudo da cinética de reação através dos modelos pseudo-segunda ordem, onde todas as amostras obedeceram ao modelo de pseudo - segunda ordem. Os resultados mostraram-se bastante promissores, sendo que a lama vermelha ativada por nitrato de cálcio a 500ºC apresentou uma...
The textile industry is responsible for the generation of effluents usually have an undersirable level of staining due to the step of dyeing, which is used dye which, when thrown into water bodies, leading to alteration of its quality and cause harmful effects the environment and human health. As a result, this study aimed to use the red mud, waste generated on a large scale in the production of aluminum, such as through adsorption of the dye Reactive Blue 19, which has a large industrial application and characteristics that hinder its removal in solution Aqueous by conventional treatments. Therefore, we chose to activate the red mud by chemical treatment (seawater, calcium nitrate and hydrogen peroxide) and thermal (400º C and 500º C) in order to identify the influence of these treatment in increasing its adsorption capacity. For this, we performed the characterization of samples of samples of red mud by determining the pH, electrical conductivity, point of zero charge (PZC) - ray diffraction (XRD) and specific surface area, and the particle size analysis was performed only for red mud in nature. Then, to determine the adsorptive capacity of activated red mud, adsorption isotherms were constructed, according to the linearized Langmuir and Freundlich models. For comparison, the same methodology was applied to activated carbon in order to determine their ability to adsorb the same dye. Was performed to study the kinetics of reaction through the pseudo-first model and pseudo-second order where all samples followed the type of pseudo-second order. The results were very promising, with the red mud activated by calcium nitrate at 500ºC showed a maximum adsorption capacity of 476.02 mg/g at pH 4. The results for the activated carbon did not indicate affinity between the adsorbate and adsorbate material, a factor... (Complete abstract click electronic access below)

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The study was conducted in two distinct properties located in the region of Serra do Sudeste, Rio Grande do Sul, Brazil: counties of, Pedras Altas and Arroio Grande. The overall objective was to evaluate the possibilities of increased production of lamb meat quality by using alternative methods to increase productivity and the effect of three finishing systems and sex on growth and development of lambs. In the first study 74 sheep were used from the cross of Corriedale and Texel rams and three Poll Dorset breed. The animals were kept on ryegrass pasture and native grassland, and supplemented daily with a mixture of soybean hulls and corn in amounts determined according to the availability of forage and the needs of each category. The sheep were subjected to the male effect and exposed to artificial reduction of photoperiod and later synchronization, needed in times (December and August). Fixed mating season was and response to the rate of estrus. The rates of estrus observed in this study show no significant difference (P <0.05) between the periods studied in the first service. However following the a second mating of sheep, differences were observed, where at the time of June a lower rate of expression of estrus (80%) was obtained. It is concluded that the use of management with the control of photoperiod in times of mating unconventional causes estrus rates over time traditionally used. In the second stage were used 90 x Corriedale lambs Texel, and 45 non-castrated males and 45 females divided into three finishing systems lamb with mother grazing (CMPN); lamb weaned, grazing (CDPN), lambs weaned, grazing supplemented with soybean hulls to 1% body weight (CDPNS). The slaughter criterion was 2.0 to 3.0 corporal condition. The effect of sex was higher in males for Initial Weight, GPTotal, GmdTotal, weight at 100 days, GP 70-100, Gmd70-100, weight at 120 days, anterior height, back Height, body weight, HCW, skin, full green guts, legs, head, heart, lung + trachea., liver vesicle., bladder and kidneys, for the female sex was higher for internal fat and fat-renal pelvic in percentages. The treatment effect was manifested to GmdTotal, GP 70-100, Gmd70-100, GP 100-120, 100-120 ADG, heart, internal fat and pelvic renal fat and percentages for HCW and full green guts.
O estudo foi realizado em duas propriedades distintas situadas na região da Serra do Sudeste, no Rio Grande do Sul, no município de Pedras Altas e no município de Arroio Grande. O objetivo geral foi avaliar as possibilidades de aumento de produção de carne ovina de qualidade, utilizando métodos alternativos de incremento de produtividade e o efeito de três sistemas de terminação e sexo no crescimento e desenvolvimento de cordeiros. Na primeira parte foram utilizando 74 ovelhas provenientes do cruzamento das raças Corriedale e Texel e três carneiros da raça Poll Dorset. Os animais foram mantidos em pastagem de azevém e campo nativo, além de serem suplementadas diariamente com uma mistura de casquinha de soja e milho em quantidades determinadas conforme a disponibilidade de forrageira e as necessidades de cada categoria. As ovelhas foram submetidas ao efeito macho e expostas à redução artificial do fotoperíodo e posterior sincronização, nas épocas necessárias (dezembro e agosto). Foi utilizado como efeito fixo a época de acasalamento e como variável resposta a taxa de estro. As taxas de estro observadas neste estudo mostram que não houve diferença significativa (P<0,05) entre as épocas estudadas no primeiro serviço, no entanto após o repasse dos carneiros, foi observada diferença, onde na época de junho foi obtida menor taxa de manifestação de estro (80%). Conclui-se que o uso do manejo com o controle do fotoperíodo nas épocas de acasalamento não convencionais provoca taxas de estro superiores à época tradicionalmente utilizada. No segundo momento foram utilizados 90 cordeiros Texel x Corriedale , sendo 45 machos não castrados e 45 fêmeas separados em três sistemas de terminação cordeiro com a mãe, mantidos em pastagem (CMPN); cordeiro desmamado, mantidos em pastagem (CDPN); cordeiro desmamado, mantidos em pastagem com suplementação com casca do grão de soja a 1% peso corporal (CDPNS). O critério de abate foi à condição corporal 2,0 - 3,0. O efeito do sexo se superior nos machos para Peso Inicial, GPTotal, GmdTotal, Peso 100 dias, GP70-100, Gmd70-100, Peso 120 dias, Altura do Anterior, Altura do Posterior, Peso corporal, PCQ, Pele, Vísceras Verdes Cheias, Patas, Cabeça, Coração, Pulmão+traq., Fígado+Vesic., Bexiga e Rins, para as fêmeas o sexo se manifestou superior para gordura interna e Gordura Pélvico-renal em valores percentuais. O efeito do tratamento se manifestou para GmdTotal, GP70-100, Gmd70-100, GP 100-120, Gmd 100-120, Coração, Gordura interna e Gordura Pélvico-renal e para valores percentuais para PCQ e V.Verdes Cheias.

This thesis describes the design, fabrication, and testing process for a microfluidic phosphate colorimeter utilized for water quality analysis. The device can be powered by, and interfaced for data collection with, a common cell phone or laptop to dramatically reduce costs. Unlike commercially available colorimeters, this device does not require the user to measure or mix sample and reagent. A disposable poly(dimethylsiloxane) (PDMS) microfluid chip, powered by an absorption pumping mechanism, was used to draw water samples, mix the sample at a specific ratio with a molybdovanadate reagent, and load both fluids into an onboard cuvette for colorimetric analysis. A series of capillary retention valves, channels, and diffusion pumping surfaces passively controls the microfluidic chip so that no user input is required. The microfluidic chip was fabricated using a modified SU-8 soft lithography process to produce a 1.67mm light absorbance pathlength for optimal Beer Lambert Law color absorbance. Preliminary calibration curves for the device produced from standard phosphate solutions indicate a range of detection between 5 to 30mg/L for reactive orthophosphate with a linearity of R²=91.3% and precision of 2.6ppm. The performance of the PDMS absorption driven pumping process was investigated using flow image analysis and indicates an effective pumping rate up to approximately 7µL/min to load a 36µL sample.

Thesis (MSc)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Lactic acid bacteria (LAB) play a vital role in reducing wine acidity and also contributing to its aroma and flavour. However, they can also be responsible for many wine spoilage problems that compromise the quality and value of wine. While Oenococcus oeni contributes positive characteristics to the sensory properties of wine, certain species of the genera, Lactobacillus and Pediococcus can affect the wholesomeness of wine by producing undesirable compounds, such as biogenic amines and ethyl carbamate. Chemical preservatives like sulphur dioxide (SO2) are used to prevent the growth of spoilage micro-organisms during the winemaking process. SO2 also acts as a reducing agent and maintains the benefits of antioxidant properties of the polyphenols of wine. However, there is a worldwide demand to reduce SO2 levels due to the increasing health related risks and other factors. All these considerations have increased the interest in research to look for new preservation strategies, and LAB-produced bacteriocins seem to be a potential alternative that has been explored in the last decade. Various types of bacteriocins have been identified and characterized. However, there are few reports on bacteriocins produced by LAB of oenological origin or on bacteriocins present in the finished wine. The present study screened 155 LAB isolates from the IWBT culture collection for bacteriocin production. The isolates originated from South African red wines undergoing spontenous malolactic fermentation (MLF). Eight strains (5%) were identified to be producers, as evidenced by strong inhibition zones formed against sensitive organisms on agar plates. The producers demonstrated a broad spectrum of antimicrobial activity by inhibiting Lactobacillus spp., Leuconostoc mesenteroides, Listeria monocytogenes and Pediococcus pentosaceus strains. Some of these bacterial genera are important in winemaking since they are potential wine spoilage bacteria. Hence these strains and/or the bacteriocins they produce could possibly find application in the food fermentation industry. The physiological results, biochemical tests and sugar fermentation profiles all gave the same results for the seven isolates, which were indicative of enterococci. The identification through 16S rRNA gene sequencing revealed that the seven tested isolates were all Enterococccus faecium. RAPD-PCR fingerprinting gave the same profile for the seven strains confirming that they were all identical on genetic level. Determining the molecular weight using SDS-PAGE showed the peptides to be below 4.6 kDa in size. PCR amplification of the enterocin P gene, sequencing and BLAST search results confirmed that all eight strains contained the enterocin P gene from Ent. faecium. The enterocin tested in this study was heat stable at 100°C (30 min), but lost 50% of its activity at 121°C (15 min). Factors such as bacteriocin production and heat resistance are among many that enable enterococci to be dominant in fermented products such as dairy foods or meat. Therefore, enterococci producing bacteriocins have potential applications in various foods and fermented products. The pH tests showed enterocin to be active over a broad pH range (2-10). Enterocin activity over a wide pH range make them potentially more suitable as natural preservatives of foods and fermented products where products are acidified or pH decreases due to natural LAB present. They also have potential applications in oenological process where pH levels are as low as 3 and 4. Proteolytic enzyme treatments with lysozyme, lipase, lyticase and catalase could not inhibit enterocin activity. This indicated that their antimicrobial activity was independent of lipid or carbohydrate moieties or hydrogen peroxide. α-Chymotrypsin and proteinase K inactivated enterocin, which indicated that the compound was proteinaceous in nature. Bacteriocin production tested in two of the isolates, #16.3 and 128.1, coincided with the exponential growth phase which occurred after 6 hours of incubation at 30°C, which was an indication of primary metabolite kinetics. The highest production of 400 AU/ml was observed after eight hours and was maintained for several hours (46 hours) in the stationery phase. The bactericidal effect of the cell free supernatants from #16.3 and 128.1 against the sensitive culture of Lactobacillus pentosus DSM 20314 was clearly demonstrated by complete inhibition of growth for most of the experimental period, while the control increased exponentially throughout the experiment. In conclusion, this study has confirmed the isolation and identification of Ent. faecium strains from wine, a genus that is rarely found in the wine environment. Although one can speculate on the origin of this bacterium in the wine e.g. human handling and contaminated water, these bacterial isolates produced enterocin P which have antimicrobial action against wine-related LAB genera and therefore have a potential role in wine spoilage control.
AFRIKAANSE OPSOMMING: Melksuurbakterieë (MSB) speel ‘n belangrike rol in die redusering van die suurgehalte van wyn en dra ook by tot die aroma en smaak daarvan. Hulle kan egter ook verantwoordelik wees vir vele wynbederfprobleme wat die gehalte en waarde van wyn negatief beïnvloed. Hoewel Oenococcus oeni positiewe karaktertrekke aan die sensoriese eienskappe van wyn verleen, kan sekere spesies van die genus, Lactobacillus en Pediococcus, die heilsaamheid van wyn beïnvloed deur ongewenste verbindings, soos biogeniese amienes en etielkarbamaat, te produseer. Chemiese preserveermiddels, soos swaweldioksied (SO₂), word gebruik om die groei van bederfmikro-organismes tydens die wynbereidingsproses te voorkom. SO₂ fungeer ook as ‘n reduseermiddel en onderhou die voordele van die antioksidant eienskappe van die poli-fenole van wyn. Daar is egter ‘n wêreldwye vraag na die redusering van SO₂-vlakke as gevolg van die toename in gesondheidsverwante risiko’s en ander faktore. Al hierdie oorwegings het belangstelling in die navorsing van nuwe preserveringstrategieë laat toeneem en MSB-geproduseerde bakteriosiene lyk na ‘n potensiële alternatief wat in die laaste dekade ondersoek word. Verskeie tipes bakteriosiene is geïdentifiseer en getipeer. Daar is egter nog weinig gerapporteer oor bakteriosiene wat deur MSB van wynkundige oorsprong geproduseer is of oor bakteriosiene wat in afgeronde wyn teenwoordig is. Die huidige studie het 155 MSB isolate van die Instituut vir Wynbiotegnologie se kultuurversameling vir bakteriosien-produsering gegradeer. Agt stamme (5%) is as produseerders geïdentifiseer, soos gestaaf is deur sterk inhibisiesones wat teen sensitiewe organismes op agarplate gevorm het. Die produseerders het ‘n breë spektrum van antimikrobiese aktiwiteit by inhiberende Lactobacillus spp., Leuconostoc mesenteroides, Listeria monocytogenes en Pediococcus pentosaceus stamme gedemonstreer. Sommige van hierdie bakteriese genera is belangrik in wynbereiding, omdat dit potensiële wynbederfbakterieë is. Hierdie isolate en/of die bakteriosiene wat dit produseer, kan dus moontlik toepassing in die voedselfermentasiebedryf vind. Die fisiologiese resultate, biochemiese toetse en suikerfermentasieprofiele het almal dieselfde resultate vir die sewe isolate, wat indikatief van enterococci was, gelewer. Die identifisering deur 16S rRNA-basispaaropeenvolging het onthul dat die sewe getoetste isolate almal Enterococccus faecium was. RAPD-PKR-vingerafdrukke het dieselfde profiel vir die sewe rasse gelewer, wat bevestig dat die rasse almal identies op genetiese vlak was. Deur die molekulêre gewig vas te stel deur middel van SDSPAGE, het dit getoon dat die peptiede kleiner as 4.6 kDa in grootte is. PKR-amplifikasie van die enterosien-P geen, die bepaling van basispaaropeenvolging en BLAST-soekresultate het bevestig dat al agt rasse die enterosien-Pgeen van Ent. faecium bevat. Die enterosien wat in hierdie studie getoets is, was hitte-stabiel teen 100°C (30 min), maar het 50% van sy aktiwiteit teen 121°C (15 min) verloor. Faktore soos bakteriosienproduksie en hittebestandheid, is van die vele faktore wat enterococci in staat stel om dominant in gefermenteerde produkte, soos suiwelprodukte of vleis te wees. Enterococci wat bakteriosiene produseer het dus potensiële toepassings in verskeie kossoorte en gefermenteerde produkte. Die pH-toetse het getoon dat enterosien-P oor ‘n breë pH spektrum (2-10) aktief was. Enterosienaktiwiteit oor ‘n wye pH spektrum maak dit potensieel meer geskik as natuurlike preserveermiddels vir kossoorte en gefermenteerde produkte waar produkte versuur word of die pH afneem as gevolg van natuurlike MSB wat teenwoordig is. Dit het ook potensiële toepassings in enologiese prosessering waar pH-vlakke so laag as 3 en 4 is. Proteolitiese ensiembehandelings met lisosiem, lipase, litikase en katalase kon nie enterosienaktiwiteit inhibeer nie. Daar is getoon dat hul antimikrobiese aktiwiteit onafhanklik was van lipiede, koolhidraatdele óf waterstofperoksied. α-Chymotripsien en proteïenase-K het enterosien onaktief gemaak, wat getoon het dat die samestelling proteïenagtig van nature is. Bakteriosienproduksie wat in twee van die stamme #16.3 en 128.1 getoets is, het ooreengestem met die eksponensiële groeifase wat na 6 ure van inkubasie teen 30°C plaasgevind het, en wat ‘n aanduiding is van primêre metabolitiese kinetika. Die hoogste produksie van 400 AU/ml is na agt ure waargeneem en is vir etlike ure (46 uur) in die stasionêre fase gehandhaaf. Die bakterie-dodende effek van die selvrye supernatant van #16.3 en 128.1 teenoor die sensitiewe kultuur van Lactobacillus pentosus DSM 20314 is duidelik gedemonstreer deur totale inhibisie van groei vir die grootste deel van die eksperimentele periode, terwyl die kontrole eksponensieel deur die hele eksperiment toegeneem het. Hierdie studie het dus die isolering en identifisering van Ent. faecium-stamme, ‘n genus wat baie selde gevind word in ‘n wynomgewing, vanuit wyn bevestig. Alhoewel daar gespekuleer kan word oor die oorsprong van hierdie bakterie in wyn bv. menslike hantering en besmette water, het hierdie rasse wel enterosien geproduseer en daarom die potensiaal om ‘n rol te speel in beheer teen verskeie bederf-MSB-genera.
TIA, NRF and THRIP

L'objectif de ce travail est de développer un système de contrôle santé intégré (CSI) de patchs composites collés sur des plaques métalliques. Ces patchs sont utilisés dans l'industrie aéronautique pour réparer des zones endommagées par fissuration ou par corrosion. Le système CSI étudié se compose de trois disques minces en céramique piézoélectrique (PZT) intégrés dans la réparation et utilisés pour émettre et détecter des ondes de Lamb se propageant dans la structure. La présence d'un défaut est révélée par l'écho résultant de la diffraction de l'onde incidente sur ce défaut. La modélisation de la propagation des ondes de Lamb permet de choisir le mode le plus approprié à la situation. En particulier, la mise en évidence d'un phénomène de focalisation conduit à privilégier le mode A₀ lorsque le milieu de propagation est très anisotrope. Des essais du système CSI ont permis de mettre au point la stratégie de contrôle. Le choix s'est porté sur des mesures en configuration échographique, pour lesquelles le même disque PZT est utilisé pour émettre et recevoir les ondes de Lamb. Par ailleurs, il apparaît nécessaire de comparer le signal mesuré à un instant donné avec un état dit de référence pour lequel d'autres techniques de contrôle non destructif ont vérifié l'absence de défaut dans la structure. Enfin, nous présentons des essais de résistance mécanique en fatigue de patchs instrumentés afin, d'une part, de vérifier que la présence des disques ne réduit pas les performances de la réparation et, d'autre part, de tester le système CSI dans un environnement plus proche des conditions opérationnelles
This document presents the development of a Structural Health Monitoring (SHM) System for composite patches bonded to aluminum plates. These patches are used in aeronautic industries to repair cracked or corroded structures. The SHM System studied consists in three thin piezoelectric ceramic (PZT) discs embedded in the repair and used to generate and detect Lamb waves propagating in the structure. The defect is revealed by the echo emitted by the diffraction of the incident wave on the defect. The modelling of Lamb waves propagation in anisotropic structures enables to select the mode. In particular, the description of the focusing phenomenon shows that the use of A₀ mode has to be preferred when the anisotropy of the propagating medium is important. To set up the monitoring strategy some experiments have been performed. Pulse-echo measurements, for which the same disc is used to excite and to detect Lamb waves, are used. Moreover, it seems necessary to compare the signal measured in a given state to a baseline signal for which other non destructive techniques have checked the lack of defect in the structure. Finally, some fatigue mechanical résistance tests of a smart repair are presented. These tests have been achieved to verify that the introduction of the discs does not degrade the performances of the repair and to test the SHM System in an environment closer to operational conditions

Orientador: Maria Lucia Pereira Antunes
Banca: Antonio Carlos Vieira Coelho
Banca: Fabiano Tomazini da Conceição
Resumo: A indústria têxtil é responsável pela geração de efluentes que, normalmente, apresentam um nível indesejável de coloração devido à etapa de tingimento, onde utilizam-se corantes que, quando lançados nos corpos d'água, levam à alteração de sua qualidade e ocasionam efeitos danosos ao meio ambiente e à saúde humana. Em vista disso, este trabalho teve como objetivo utilizar a lama vermelha, resíduo gerado em larga escala na produção de alumínio, como meio adsorvedor do corante Reativo Blue 19, o qual possui grande aplicação industrial e características que dificultam sua remoção em solução aquosa por meio de tratamentos convencionais. Sendo assim, optou-se por ativar a lama vermelha através de tratamento químico (água do mar, nitrato de cálcio e peróxido de hidrogênio) e térmico (400ºC e 500ºC), visando identificar a interferência desses tratamentos no aumento de sua capacidade adsortiva. Para isso, foi realizada a caracterização das amostras de lama vermelha através da determinação do pH, condutividade elétrica, ponto de carga zero (PCZ) difração de raios - x (DRX) e área superficial específica, sendo que a análise granulométrica foi realizada somente para a lama vermelha "in natura". Em seguida, visando determinar a capacidade adsortiva da lama vermelha ativada, foram construídas isortermas de adsorção, linearizadas segundo os modelos de Langmuir e Freundlich. Para efeito de comparação, a mesma metodologia foi aplicada ao carvão ativado visando determinar sua capacidade em adsorver o mesmo corante. Foi realizado o estudo da cinética de reação através dos modelos pseudo-segunda ordem, onde todas as amostras obedeceram ao modelo de pseudo - segunda ordem. Os resultados mostraram-se bastante promissores, sendo que a lama vermelha ativada por nitrato de cálcio a 500ºC apresentou uma... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The textile industry is responsible for the generation of effluents usually have an undersirable level of staining due to the step of dyeing, which is used dye which, when thrown into water bodies, leading to alteration of its quality and cause harmful effects the environment and human health. As a result, this study aimed to use the red mud, waste generated on a large scale in the production of aluminum, such as through adsorption of the dye Reactive Blue 19, which has a large industrial application and characteristics that hinder its removal in solution Aqueous by conventional treatments. Therefore, we chose to activate the red mud by chemical treatment (seawater, calcium nitrate and hydrogen peroxide) and thermal (400º C and 500º C) in order to identify the influence of these treatment in increasing its adsorption capacity. For this, we performed the characterization of samples of samples of red mud by determining the pH, electrical conductivity, point of zero charge (PZC) - ray diffraction (XRD) and specific surface area, and the particle size analysis was performed only for red mud "in nature". Then, to determine the adsorptive capacity of activated red mud, adsorption isotherms were constructed, according to the linearized Langmuir and Freundlich models. For comparison, the same methodology was applied to activated carbon in order to determine their ability to adsorb the same dye. Was performed to study the kinetics of reaction through the pseudo-first model and pseudo-second order where all samples followed the type of pseudo-second order. The results were very promising, with the red mud activated by calcium nitrate at 500ºC showed a maximum adsorption capacity of 476.02 mg/g at pH 4. The results for the activated carbon did not indicate affinity between the adsorbate and adsorbate material, a factor... (Complete abstract click electronic access below)
Mestre

The depth to which sophisticated technologies are entering into every facet of the society is causing a significant shift in where, when, and how as individuals and as a collective body work together, and how the educational systems should be structured to prepare students for a massive effective life of the 21st century. This shift, is the drive towards the use of educational games as a learning tool in schools and has led to diverse benefits and opportunities of computer game play. The study examine in detail how Kodu Game Lab is used to foster quality teaching-learning process for pupils’ in primary schools. The aim was to understand collaborative learning interaction among pupils’ using Kodu Game Lab. The participant of this study were seven 9 year old pupils’ (5 males and 2 females) from which five pupils’ were selected for intensive observation. Content analysis (CA) was used in analyzing the process by coding raw visual images and categorizing the frames into three levels of interaction. Those frames in which at least three nonverbal cues (facial expression, gaze and gesture) were used within the group were coded as High Level Interaction. Secondly, frames where there were at least two nonverbal cues used were coded as Medium Level Interaction. And thirdly, frames where at least one nonverbal cues used were coded Low Level Interaction. The result show that one of the groups had High, Medium, and Low Level of Interaction while other (two groups) exhibit Medium and Low Level Interaction respectively. In addition, the findings shows that pupils’ interaction with their peers when using Kodu Game Lab is apparent through the use of nonverbal cues which results to High, Medium, and Low Level Interaction within the group. On the one hand, pupils’ interaction with the teacher when using Kodu Game Lab is also apparent through the use of non-verbal cues but the interaction level of pupil’s with their teacher is of Medium and Low level.

This thesis discusses the development of a lab on a chip (LOC) ion separation for river water quality monitoring using a capacitively coupled conductivity detector (C⁴D) with a novel baseline suppression technique. Our first interest was to be able to integrate such a detector in a LOC. Different designs (On-capillary design and on-chip design) have been evaluated for their feasibility and their performances. The most suitable design integrated the electrode close to the channel for an enhanced coupling while having the measurement electronics as close as possible to reduce noise. The final chip design used copper tracks from a printed circuit board (PCB) as electrodes, covered by a thin Polydimethylsiloxane (PDMS) layer to act as electrical insulation. The layer containing the channel was made using casting and bonded to the PCB using oxygen plasma. Flow experiments have been conduced to test this design as a detection cell for capacitively coupled contactless conductivity detection (C⁴D). The baseline signal from the system was reduced using a novel baseline suppression technique. Decrease in the background signal increased the dynamic range of the concentration to be measured before saturation occurs. The sensitivity of the detection system was also improved when using the baseline suppression technique. Use of high excitation voltages has proven to increase the sensitivity leading to an estimated limit of detection of 0.0715 μM for NaCl (0.0041 mg/L). The project also required the production of an autonomous system capable of operating for an extensive period of time without human intervention. Designing such a system involved the investigation of faults which can occur in autonomous system for the in-situ monitoring of water quality. Identification of possible faults (Bubble, pump failure, etc.) and detection methods have been investigated. In-depth details are given on the software and hardware architecture constituting this autonomous system and its controlling software.

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A jaca (Artocarpus heterophyllus. Lam) pertence à família das Moraceae, ao gênero Artocarpus e é originária da Ásia. O tamanho dos frutos associado à exsudação do látex e o seu aroma característico acentuado, tem sido fatores limitantes quanto ao seu consumo. O objetivo do presente estudo foi avaliar a qualidade da jaca minimamente processada e acondicionar em diferentes tipos de embalagens, sob temperatura de 3°C durante 12 dias. O experimento foi desenvolvido no Laboratório de Tecnologia de Produtos de Origem Vegetal do Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal de Campina Grande, utilizando um delineamento experimental inteiramente casualizado em esquema fatorial 4 x 7 (4 tipos de embalagens e 7 intervalos de tempo), com 3 repetições totalizando 84 tratamentos. As embalagens usadas foram: polipropileno (PP), politereftalato de etileno (PET), poliestireno expandido recobertas com filme de cloreto de polivinila (PVC) e saco plástico de polipropileno biorientado (BOOP). Foram realizadas analises físico-química e de compostos bioativos da polpa. Os dados foram submetidos a análise de variância e regressões polinomiais. Foi significativo do tempo de armazenamento e dos tipos de embalagens. Houve acréscimos significativo em relação tempo e entre tipos de embalagem para as variáveis físico-químicas: Perda de Massa, Sólidos Solúveis, Acidez Titulável e pH. Os compostos bioativos: Clorofila, Carotenoides, Flavonoides e Antocianinas aumentaram com o tempo de armazenamento e diferiram com o tipo de embalagem. Os níveis de Ácido ascórbico foram reduzidos de forma significativa e os Compostos fenólicos totais sofreram também reduções com a evolução da maturação dos frutos.
The jaca (Artocarpus heterophyllus, Lam) and originated from Asia belongs to the Moraceae family, and Artocarpus genre. The size of the fruits associated to the latex exudation and its marked aroma characteristic has been limiting factors in its consumption. The had as of the objective to evaluate the quality of the processed jackfruit and to pack in different types of packages under temperature of 3° during 12 days. The experiment was developed in the Laboratory of Technology of Vegetable Sources at the Center of Sciences and Agrifood Technology of the Federal University of Campina Grande, using a completely randomized experimental design in a factorial scheme 4 x 7 (4 storage bags nature and 7 time intervals) with 3 replicates totalizing 84 treatments. Polypropylene (PP), polyethylene terephthalate (PET), expanded polystyrene coated with polyvinyl chloride film (PVC) and bioriented polypropylene plastic bag (BOOP) were used as packing materials during seven processing periods. Physical and chemical analyzes of the bioactive pulp compounds were performed. Data was submitted to analysis of variance and regressions. Was significant effect of the storage time and types of packages. The physic chemical variables mass loss, soluble solids, titratable acidity and pH were significantly influenced by the processing time and types of packaging increasing these with the time of processing. The bioactive compounds Chlorophyll, Carotenoids, Flavonoids and Anthocyanins also were affected significantly with the time of storage and type of packaging, increasing these with the time of processing. Ascorbic acid levels and total phenolic compounds were reduced with the evolution of fruit maturation.

Economic development in an area attracts more people to live in it. This increment drives the necessity to improve available infrastructure, like roads for instance, to satisfy a higher demand. Bigger roads and higher number of vehicles have raised the concern about possible pollution coming from these sources In this thesis, copper coming from road runoff in a peri-urban catchment in Portugal was analyzed. The catchment is located in the Coimbra region, center of Portugal. In order to model copper pollution in road runoff, it is necessary to couple a hydrological model and a water quality Based on a previous study (Kalantari, Ferreira, Walsh, Ferreira, & Destouni, 2017) a physical based hydrological model  MIKE SHE  coupled with the hydraulic model MIKE 11was updated and further coupled with  ECO Lab to simulate water quality and ecological processes. The results show an improvement of the hydrological model compared with the original one, nash-sutcliffe efficiency was raised from 0.59 to 0.77 and the coefficient of determination varied from 0.64 to 0.79. For copper the model behavior for punctual and distributed sources was analyzed. For punctual sources, highest concentrations were present in the grid points where the incoming sources were located in the tributaries, and these concentrations are rapidly reduced downstream. On the other hand, distributed sources approach gives higher concentrations near the end of the river than in the tributaries upstream. Comparing time-averaged model results along the river, with fresh water quality criteria according to U.S. EPA (2004), for punctual sources an extension of 978 meters (7,6% of the river) presents a concentration above CCC or CMC, on the contrary, for distributed sources the extension is lower with 494 meters (3,8%). The organic carbon partitioning coefficient have bigger influence on the results than other factors, nevertheless this influence is not marked. Modeled copper values do not agree well with the mesured values specially for periods with higher discharge as the model simulates lower concentration with higher discharge and viceversa. Copper boundary values for the model represent a big challenge considering limited data available. This thesis gives good overview about the coupling process between MIKE 11 and ECO Lab, as well as analyzes the importance of some factors as well as model limitations and uncertainties.

The objective of the study was to determine the feed conversion efficiency (FCE), carcass characteristics, physico-chemical quality, fatty acid (FA) composition and shelf life of pork from pigs fed diets containing either 0% (T1), 2.5% (T2), 5% (T3) or 7.5% (T4) Moringa oleifera leaf meal (MOLM). Consumer health-related perceptions on pork and fatty acids were also investigated. Twenty four crossbred Large White x Landrace pigs of both sexes at 18 weeks of age and initially weighing 71.6 kg on average were housed individually and had ad libitum access to one of the four dietary treatments for a period of six weeks. Average daily feed intake (ADFI) and average daily gain (ADG) and feed conversion ratios (FCR) were calculated as an indication of FCE and pigs were slaughtered at an average live weight of 99.6 kg. Carcass traits such as back fat thickness (BFT), carcass temperatures and pH readings taken 45 minutes and 24 hours (pH45 and pHu) post mortem were recorded. M. longissimus thoracis et lumborum (LTL) samples were taken from each carcass for the determination of lightness (L*), redness (a*), yellowness (b*), thawing loss percentage (TL%), cooking loss percentage (CL%), Warner Bratzler Shear Force (WBSF), shelf life and FA composition. Furthermore a survey was conducted amongst 80 University of Fort Hare Students to determine their health-related perceptions on pork and fatty acids as well as their pork consumption frequency using questionnaires. The FCE of pigs fed on 0-5% MOLM (T1, T2 and T3) diets did not differ significantly, but the FCE of pigs fed 7.5% MOLM (T4) was significantly (p<0.05) reduced. No significant relationship was reported between inclusion of MOLM carcass characteristics and physico-chemical pork quality. There was however a significant improvement (p<0.05) in the shelf life of the pork from MOLM fed pigs in terms of colour and odour during 10 days of refrigerated storage (at 3±1°C). There was a significant (p<0.05) reduction in the total intramuscular fat (IMF) content and the saturated fatty acid (SFA) C18:0 (stearic acid) content and an overall non-significant (p>0.05) increase in the poly unsaturated fatty acid (PUFA) content of pork from MOLM fed pigs. The possible reason for this is that the feeding of MOLM was commenced when the pigs were at an advanced age and weight. The survey revealed that the majority of interviewed students consume fresh (39.7%) and processed (32.4%) pork two to three times a week, perceive pork to be generally healthy (70%) and the second most healthy meat type (39.5%). While the majority (55.4%) were aware of the health implications of FAs they did not know which FA classes pose more of a health risk (51.3%). In conclusion2.5% and 5% of MOLM in finisher pig feed did not negatively affect FCE, carcass characteristics or physico-chemical meat quality; significantly improved pork shelf life and reduced total IMF and SFA content of pork but 7.5% MOLM negatively affected FCE; and the majority of students perceive pork to be the second most healthy type of meat and are generally aware of the health implications of FAs.