Dissertations / Theses on the topic 'Meat products/microbiological analysis'

Surtos de listeriose têm sido causa de preocupação para indústrias de alimentos e profissionais da saúde. Os testes de rotina para detecção de Listeria sp em alimentos são demorados e envolvem o uso de meios de cultura seletivos para enriquecimento e semeadura. Neste estudo, a presença de Listeria sp, em amostras de produtos cárneos, foi investigada por testes imunológicos rápidos (Tecra® Listeria VIA, Tecra® Listeria UNIQUE e BioControl VIP® para Listeria) e pelo método clássico (Health Protection Branch, Canadá). A concordância entre o método clássico e os testes rápidos foi estabelecida com limite de 95% de confiança. Verificou-se que os testes VIA e VIP® são de fácil execução e rápidos, além de apresentarem desempenho comparável ao do método clássico, independentemente do alimento avaliado. O teste UNIQUE apresentou desempenho variável com a amostra e gerou um número elevado de resultados positivos falsos, o que dificulta seu emprego.
Outbreaks of human listeriosis have been a cause of concern to the food industry and health professionals. The routine methods for detecting Listeria sp in foods are time-consuming and involve the use of selective enrichments and culturing on selective agars. In this study, the presence of Listeria sp in 120 meat and meat products samples was investigated by three rapid immunoassays (Tecra® Listeria VIA, Listeria UNIQUE and BioControl VIP®.+ for Listeria) and a cultural procedure. The detection of Listeria sp by the cultural method was done according to Canada\'s Health Protection Branch Method and the detection using rapid tests was done following the manufacturers\' instructions. The agreement between cultural and rapid tests was established at a confidence limit of 95%. Eighty-one samples (67.5%) were Listeria sp positive by at least one of the four methods. L. monocytogenes was present in 49.2% of the samples. Sixty-four samples (53.3%) were positive by the cultural procedure. For the rapid tests, 62 (51.7%) were VIA positive, 65 (54.2%) were VIP® positive and 41 (50.2%) were UNIQUE positive. Fifty-five samples (45,8%) were positive by the cultural method and VIA simultaneously, 55 (45.8%) by the cultural method and VIP® and 35 (43.2%) by the cultural and UNIQUE. VIA detected 4 positive samples that were not detected by any of the other methods, while VIP detected 7 positive samples and UNIQUE only 2. VIA and VIP® tests are fast and easy to execute. They also performed similarly to the cultural method despite the food matrix. UNIQUE, on the other hand, was strongly influenced by the sample type and generated a high number of false positive results what makes its use unpractical.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This study aimed to isolate and identify Staphylococcus aureus in fresh sausages that were handmade or industrially produced, and characterize isolates for susceptibility to antimicrobial agents and the presence of virulence genes. We collected 86 samples of fresh sausages, pork and chicken, in butchers of the city of Aparecida de Goiânia, Goiás. The temperature of the sausages was also measured at the time of collection. After microbiological analysis, the isolates were submitted to the antibiogram by disk diffusion technique, to typing by Pulsed Field Gel Electrophoresis and to detection of virulence genes by Polymerase Chain Reaction. Most sausages collected (68.6%) showed temperature above 4 ° C, ranging from 4.98 °C to 9.89 °C. Six samples were contaminated with Staphylococcus sp., with seven isolates, but with scores within the standard set by the Brazilian law (5.0 x 103 colony forming units per gram). Of the seven isolates obtained from different brands, collected in different butchers, three were identified as Staphylococcus aureus by detection of the femA gene, were sensitive to all antibiotics tested and showed 100% similarity by Pulsed Field. The genes encoding the hemolysins A and B, and enterotoxin H were detected in three of S. aureus strains and in one of them were already detected the genes encoding enterotoxins G and I. The survey allowed to detect S. aureus in fresh sausages, and the possibility of expression of enterotoxins genes., The presence of isolates genetically identical identified in samples obtained of distinct brands and from different butchers indicate common source of contamination or spread of particular strains in this type of food. It should be noted therefore the need to observe the product's storage conditions such as temperature when that significant amounts of toxins are not produced and become risk for the occurrence of outbreaks.
Este estudo teve como objetivo isolar e identificar Staphylococcus aureus em linguiças frescais, fabricadas artesanalmente ou de modo industrial, e caracterizar os isolados quanto à suscetibilidade a antimicrobianos e à presença de genes de virulência. Foram coletadas 86 amostras de linguiças frescais, suína e de frango, em açougues do Município de Aparecida de Goiânia, Goiás. A temperatura das linguiças foi aferida no momento da coleta. Após análise microbiológica, realizou-se o antibiograma pela técnica de disco-difusão, tipagem microbiana por eletroforese em gel em campo pulsado e detecção de genes de virulência pela Reação em Cadeia de Polimerase. A maioria das linguiças coletadas (68,6%) apresentaram temperatura superior a 4 ºC, variando de 4,98 ºC a 9,89 ºC. Seis amostras estavam contaminadas por Staphylococcus sp., sendo obtidos sete isolados, porém com contagens conforme o padrão estabelecido pela legislação brasileira em vigor (5,0 x 103 unidades formadoras de colônia por grama). Dos sete isolados, três obtidos de amostras de marcas distintas, coletados em açougues diferentes, foram identificados como Staphylococcus aureus pela detecção do gene femA, apresentaram sensibilidade a todos os antibióticos testados e 100% de similaridade pela técnica de Pulsed Field. Foi detectada a presença de genes que codificam as hemolisinas A e B e a enterotoxina H nos três isolados de S. aureus e em um deles ainda foram detectados os genes que codificam as enterotoxinas G e I. A pesquisa permitiu detectar S. aureus em linguiças frescais e a possibilidade de expressão de genes de enterotoxinas. A presença de isolados semelhantes geneticamente, identificados em amostras oriundas de açougues diferentes e de marcas distintas, indicam origem comum de contaminação ou difusão de linhagens particulares neste tipo de alimento. Ressalta-se portanto, a necessidade de se observar as condições de armazenamento do produto como a temperatura, para que quantidades expressivas de toxinas não sejam produzidas e se tornem risco para a ocorrência de surtos de origem alimentar.

This investigation was done with the objective to determine the microbiological load of the main meat products such as: beef, chicken meat, sausage, and viena sausage which are sold in the Riobamba city markets. This investigation was carried out in the Microbiological Laboratory Livestock Science faculty of the Polytechnical Superior school. Specific chemical products were used to determine mesofilas (37 degrees C), xicrofilas (5 degrees C), and termofilas bacteria which did not develop at 45 degrees C, however exicrofilas and mesofilas bacteria were found in every market and meat product in this study. The meat product hygiene is the same in all market conditions. There is no change in the handle or conservation of these products, especially with the handmade products such as sausage and long sausage. My personal point of view is that they are more dangerous for our health because they are not cooked before eaten and because of the way they are conserved. On the contrary, when the meat was cooked, termofilas were not found, since at 50°C temperature, the bacteria begins to be destroyed by the warmth, which give us some confidence to eat cooked food. However, the problem continues because the toxins that the bacteria release are more dangerous, therefore, we must investigate the toxin matter released by the bacteria in the meat products. When meat is eaten, such as hamburgers or roasted meat, there is a risk of acquiring some diseases. The expenses of an investigation of this kind are too high to perform a complete biochemical test which would provide better results that can be relied on. This thesis is patterned to make a project aimed at improvement of the hygiene and quality of these products that are used on a daily basis. In all, the situation in Ecuador is the same as in this city, it is extremely urgent to stress the importance of this issue. The consumption of meat of bad quality is not a good source of nutrition for our people.

Prior to commencement of the work reported in this thesis, the design and operation of food remgerati'on systems had focused very largely on the equipment side of the evaporator. However, from the beginning of the 1970s, the picture changed dramatically, largely as a result of a whole new raft of food temperature legislation, both national and international, based on food safety requirements. As a consequence, industry was forced to consider, much more closely, the factors affecting throughput rates, product yield, energy costs and the criteria for optimal organoleptic quality. This created a soaring demand for process design and operating data, but few such data were available. A wide-ranging research programme was therefore initiated to provide the data required. Not least of the challenges to be overcome, were the problems created by the size, shape, complexity of composition and variability of meat and meat products. A principal requirement was thus the design, development and construction of a complete range of dedicated pilot plants, with the necessary control and instrumentation to overcome these problems. It was realised from the outset, that the data required, for the large range of meat and meat products, could never be obtained by experiment alone, because of the sheer number of product and environmental variables that had to be included. A central plank of the research programme was thus the development of predictive models. This thesis describes the various research programmes that were set in place to provide the required design and operating data. The investigations have produced many contributions to knowledge and, through thermal analysis and measurement, have advanced understanding of chilling, freezing and thawing of meat and meat products. More recently this has been extended to baked goods and other chilled foods in retail display. The data generated have ensured improved design of process facilities, reduced costs to industry and enhanced both food safety and quality.

An industrial Fourier transform infrared (FTIR) milk analyser has been adapted for the proximate analysis of fresh or cooked meat and meat products. Stable freeze-dried samples of ground beef and bologna were prepared for the calibration of an FTIR spectrometer equipped with a 37-mum transmission cell maintained at a constant temperature of 65°C and were analysed for fat, protein, moisture, and ash by the official methods of analysis of the Association of Official Analytical Chemists (AOAC) prior to instrumental measurement. The requirement to prepare a "milk-like" emulsion of meat for FTIR analysis led to the development of two prototype high-pressure homogenizers specifically designed to produce analytical volumes of emulsions in which the largest residual colloids present in suspension would have dimensions smaller than 1 mum. Emulsified samples were examined by transmission electron microscopy and laser light scattering spectroscopy to determine the size distribution of fat globules and the dimensions of the residual insoluble fragments of protein.
"Milk-like" emulsions of meat passed three times through a high-pressure homogenizer operating at 20,000 psi (138 MPa) had an average fat globule diameter of less than 320 nm. Also, the use of high-pressure homogenization eliminated the need to filter out insoluble proteins from connective tissues prior to the infrared analysis, resulting in a more accurate determination of the protein content in the meat samples. The results of validation studies conducted with both fresh and freeze-dried samples demonstrated that it is possible to analyse meat samples simultaneously for fat, protein, carbohydrates and moisture with good accuracy in approximately 7½; minutes per sample employing existing FTIR instrumentation used for the routine analysis of milk and dairy products.

Computed Tomography and Microcomputed Tomography are X-ray based technologies. They were tested in this thesis as potential tools for the optimization of the processing of dry-cured meat products. On one hand, several prediction models and Computed Tomography analytical tools were developed for the non-destructive analysis of water activity, salt content and water content distribution within dry-cured hams during processing and were successfully applied to three case studies. On the other hand, Microcomputed Tomography were used to characterize, evaluate and correlate the changes in the microstructure with the texture of non-acid pork lean fermented sausages. Some Microcomputed Tomography parameters could be correlated with the instrumental texture, although the Microcomputed Tomography was not accurate enough to distinguish between lean and fat when these constituents were emulsified. In conclusion, Computed Tomography and Microcomputed Tomography can be considered as suitable technologies for the non-destructive characterization and for the optimization of dry-cured meat processing.
La Tomografia Computeritzada i la Microtomografia Computeritzada són tecnologies basades en raigs X. Ambdues es varen testar en aquesta tesis com a eines potencials per l'optimització del processat de productes carnis curats. Per una banda, es varen desenvolupar diversos models de predicció i eines analítiques derivades de la Tomografia Computeritzada, per l’anàlisi no destructiu de la distribució de l’activitat d’aigua i els continguts de sal i d’aigua durant el processat de pernils curats, aplicant-se posteriorment de manera satisfactòria a tres casos d’estudi. Per altra banda, la Microtomografia Computeritzada es va utilitzar per caracteritzar, avaluar i correlacionar canvis en microestructura i textura d’embotits crus curats elaborats amb baix contingut de greix. Alguns paràmetres de la Microtomografia Computeritzada es van poder correlacionar amb la textura instrumental, encara que es va observar que la Microtomografia Computeritzada no permetia distingir acuradament entre magre de porc i greix quan aquests components es trobaven emulsionats.

A single stage reversed phase high performance liquid chromatography (RP HPLC) separation of animal fat triacylglycerols (TAGs) has been developed for coupling with atmospheric pressure chemical ionization tandem mass spectrometry using an ion trap mass spectrometer. The method developed offers significant improvements on existing methods for TAG analysis, giving better resolution of TAGs with similar equivalent carbon number (ECN), and good separation of TAGs with odd ECN and TAG regioisomers of animal fats. Although the analysis times for chromatographic analysis of these TAGs are long, this is compensated by better separation of highly unsaturated TAGs. Development of an ultra high performance liquid chromatography method has reduced the run time by half, while maintaining separation and resolution. The TAG profiles of fats reflect their fatty acid (FA) compositions, showing a high proportion of unsaturated FAs for chicken and pork, whereas, saturated FAs are dominant in the major TAGs detected in beef and lamb. The improved RP HPLC separation of TAGs developed in this study has been shown to give more reliable discrimination of different animal species than previous methods including analysis of FAs as the methyl esters and RP HPLC separations of intact TAGs. All animal species separated well in the principal component analysis (PCA) plot of TAG profiles, whereas in the PCA plot of FA, chicken plots very close to pork fat, particularly ham. The profiles of TAGs in animal species highlight a number of components that are important for species discrimination. The meat products of different species (beef, pork, chicken and lamb) cooked by microwave, roasting and currying are separated well in the PCA scores plot. This work shows that the discrimination of meat from different animal species is possible for both raw and cooked meat products, and reveals that the differences produced by the various cooking methods were less than the variations observed between species. The loadings values for the scores plot of TAGs for raw and cooked meat products are similar to the raw meat in different animal species and have the same important descriptors for discrimination. Hence, analysis of intact TAGs in cooked food products has considerable potential for detection of adulteration of cooked meat-based food products.

The objective of the study was to determine the effects of Aloe ferox inclusion in drinking water on growth performance, blood biochemistry, physico-chemical characteristics, fatty acid profile and oxidative stability of broiler meat. The importance of A. ferox as a medicinal plant and factors that influence its utilization by communal poultry farmers were also investigated by use of a questionnaire survey. The survey revealed that the majority of respondents (84.6%) faced health challenges in their chickens and many relied (96.2%) on A. ferox to treat diseases and control parasites. The study also revealed that the choice of medicine (traditional or conventional) was influenced (P<0.05) by level of education and income. In the second phase of the research, a total of 600 Ross 308 day-old broilers, were randomly put in 6 treatment groups with 4 replicates, each having 25 birds. Fresh aqueous A. ferox leaf juice (ALJ) was administered in drinking water at a dosage of 20ml/litre to T1, T2 and T3 from day one to day 35, day one to day 14 and day 15 to day 28, respectively. Birds in T4 and T5 (positive controls) were treated with terramycin at the recommended dosage of 14g/litre of drinking water from day one to day 6 and from day 15 to 20, respectively; and birds in T6 (negative control) received distilled water from day 1 to 35. Feed Intake (FI), average daily gain (ADG) and feed conversion ratio (FCR) were calculated for the 5 week trial. After slaughter, carcass characteristics particularly dressing percentage (DP) and relative organ weight (ROW) were calculated. Serum biochemistry was also determined. For meat quality, pH and color were recorded 45 minutes and 24 hours after slaughter from the breast muscle. Fatty acid profiling and oxidative stability were determined using meat samples from the breast and thigh muscles. The results for growth performance showed that thebirds which were given A. ferox for the first two weeks (T2) consumed significantly (P>0.05) more feed (189.4g) than those in the negative control (159.6g) at the beginning of the starter phase. Subsequently, their ADG recorded on day 7 (27.1g) and day 14 (43.1g) were significantly (P<0.05) higher than the negative control (22.8g and 36.2g, respectively). Significant treatment effects (P<0.05) for FCR were reported in the 4th week for the birds that received A. ferox throughout (T1: 3.5). Carcass characteristics were not significantly (P>0.05) affected by A. ferox inclusion in drinking water. The highest high density lipoprotein (HDL) values (2.78 mmol/L) were yielded in T2and T3 had the lowest values (0.61mmol/L) for low density lipoprotein (LDL). For physico-chemical properties, no significant effects (P>0.05) of treatment on pH, colour, cooking loss and tenderness were observed. However, the group treated with A.ferox throughout the production cycle, had the highest pH (6.2), lowest lightness (38.5), highest redness (4.1), highest tenderness (13.86N) and the lowest cooking loss (12.6%). Significant treatment effects (P<0.05) were observed on the composition of the PUFA eicosatrienoic acid (C20:3c8, 11, 14(n-6)) of the breast muscle which was significantly lower in the A. ferox treatment groups than the positive controls. For the thigh muscle, there were significant (P<0.05) treatment effects on composition of palmitoleic acid (C16:1c9) and g-linolenic acid (C18:3c6, 9, 12 (n-3)). No significant (P>0.05) effects were found on oxidative stability of both thigh and breast muscles. In conclusion, the wide use of A. ferox by communal chicken farmers showed its importance as a medicinal plant. Apart from it being an effective medicinal plant, A. ferox inclusion in drinking water results in improved FI, ADG, reduced in LDLC and better g-linolenic and palmitoleic acid composition in the meat.

The research program addressed in this study was to do an analysis of the potentials of the marketing of ostrich meat in the South African market. Being the world leader in the ostrich industry, the research’s emphasis was to establish reasons why the meat industry does not explore the South African meat market. To achieve this object, a literature study to determine the key components of the current situation was undertaken and used as a theoretical model to analyse the current situation in the market as well as in the ostrich industry. In addition to the literature study, an empirical study was conducted to identify some critical issues that have an influence on the potential of the domestic market. The survey method used, based on the key components gained from the literature study, consisted of an in-depth scan of the macro-environment and thorough investigation of the target industry. The investigation involved using the Internet and World Wide Web, print media, personal interviews and telephonic interviews. The result of the literature study was finally combined with the results of the empirical study and some recommendations were made. The recommendations were applicable to the ostrich industry in so far that implementing some plans for the meat industry can have serious consequences for the other products of the ostrich industry

The diploma thesis deals with sensory evaluation of selected types of meat products, specifically sausages. Different types of sausages, which contained added chemicals and spices, were compared. The theoretical part describes the properties of meat and meat products and the basic technological procedures used for their processing and production. Furthermore, added substances and spices, which are often considered as flavorings or preservatives, were characterized. The principles of correct performance of sensory analysis and sensory perception of food were also presented, which include a description of the sensory workplace, sample preparation, its implementation, procedure and various evaluation methods used. The experimental part describes the specific work tools used and the conditions under which the evaluation took place. A total of 12 types of sausages were evaluated, 7 of which came from meat production and 5 were prepared in the laboratory of food chemistry at Brno University of Technology. The differences between the samples of sausages, which differed in content and type of added chemicals and spices, were clearly shown using ray graphs. Then the Grubbs test was used, which excluded outliers from the final evaluation. These values were further excluded from further evaluation. The Kruskall-Wallis test was used to distribute the resulting mean values and to determine whether there was a statistically significant difference in sensory evaluation between the results. An appendix to the Kruskall-Wallis test Dunn's test was used to divide the resulting values into given groups according to statistically significant difference and similarity. The analysis of the main components of the so-called PCA was used to find the differences and similarities of the samples included in the groups.

Mutton meat was tested in different products in order to obtain prototype products in which mutton can effectively be used without the objectionable mutton off flavor. Mutton flavor reduction was achieved in the processed meat products by: (a) lowering mutton fat to a level of 10% or less, (b) using spices, smoking and/or curing, (c) substituting fat from beef or pork for mutton fat, and (d) the action of microbial starter cultures. Four taste panel sessions were set up to rate these products against an all beef or all pork control for consumer acceptability. Taste panel results indicate that flavor had the greatest effect on overall acceptability of these products, compared to texture and appearance. Proximate meat analysis for fat, protein, moisture and ash were performed using the Technicon InfraAlyzer 400R and the results were compared with values obtained by reference AOAC methods. Correlation coefficients of 0.992, 0.867, 0.992 and 0.511 were obtained for fat, protein, moisture and ash respectively. The two methods were not significantly different (p = .05). These results indicate that the InfraAlyzer may be used as a rapid method for proximate analysis of fat, protein and moisture.

Orientador: Arnaldo Yoshiteru Kuaye
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Lotes de amostras de cortes de coxa e de filé de peito de frango, previamente acondicionadas sob diferentes sistemas de embalagens (recobertas por filme de alta permeabilidade ao oxigênio (AR), em vácuo (VC) e em atmosfera modificada (AM) com CO2 e N2) foram submetidas à irradiação ionizante com uma fonte de 60Co. Com o objetivo de avaliar a influência do processo sobre a vida útil e manutenção da qualidade foram avaliados parâmetros físico-químicos, microbiológicos e sensoriais das amostras processadas e armazenadas sob refrigeração a temperatura de 7±1ºC por períodos de 42 dias (AR) e três meses (VC e AM). Os tratamentos das amostras de frango por irradiação não promoveram alteraçao de cor, determinada objetivamente, enquanto a oxidação lipídica, avaliada pelas determinações TBARS (substâncias reativas ao ácido tiobarbitúrico) como indicador, apresentaram tendência de valores crescentes, conforme incremento da dose. Os valores de pH das amostrascontrole coxa/AR,VC e AM e peito/AR,VC e AM não apresentaram diferenças significativas durante todo o período de armazenamento. A aplicação da irradiação às amostras de carne de frango acondicionadas em filme de alta permeabilidade ao oxigênio (coxa/AR e peito/AR) e em filme barreira (coxa/VC, peito/VC, coxa/AM e peito/AM) promoveu uma sensível redução de E.coli, Pseudomonas spp, e enterobacteriaceas totais, porém no sistema de embalagem AR as bactérias láticas e os bolores e leveduras apresentaram maior resistência. Nas amostras acondiciondas em filme com barreira (vácuo e atmosfera modificada) as bactérias láticas foram as mais resistentes. Não foi observado em nenhuma amostra o desenvolvimento de Brochothrix thermosphacta e Listeria monocytogenes durante todo o periodo de armazenamento. Os resultados das análises cromatográficas de substâncias oriundas da degradação lipídica revelaram perfis de compostos voláteis similares para amostras submetidas às três condições de atmosfera. O incremento nas doses de irradiação acima de 3kGy, independente do tipo de sistema de embalagem utilizada, promoveu alteração crescente do odor de queimado no produto revelando assim este valor como limite recomendável para a garantia de uma maior vida útil sem alteração sensorial perceptível. Observou-se uma sensível extensão da vida útil das amostras de coxa/AR em 2,8 vezes, peito/AR em 4,0 vezes e em amostras embaladas em filme barreira (coxa/VC, e peito/VC, coxa/AM e peito/AM) em 6,0 vezes superior ao das amostras-controle. O processo de irradiação demonstrou ser uma ferramenta potencial de utilização para extensão da vida útil e melhoria da qualidade de cortes de frango
Abstract: Samples of raw chicken thigh and chicken breast fillets previously packed in different packaging systems [wrapped in high oxygen-permeable film (AIR), vacuum packed (VC) and CO2 and N2 modified-atmosphere-packed (MA)] were submitted to ionizing radiation delivered by a 60Co unit. A series of physical-chemical, microbiological and sensory parameters were evaluated to assess the effect of the radiation process on the shelf-life and keeping quality of chicken cut samples exposed to radiation and subsequently cold-stored at 5±1ºC for 39 days (AIR) and 3 months (VC and MA). The results of instrumental color assessment trials showed that the radiation treatments investigated in this study did not cause any color changes in any of the radiation-treated chicken cuts. On the other hand, lipid oxidation - measured using the TBARS (thiobarbituric acid reactive substances) content as indicator ¿ exhibited a gradual increase proportional to the increase of the radiation dose. The pH values of the chicken thigh/AIR, VC and MA and chicken breast/AIR, VC and MA control samples did not exhibit any significant differences throughout the storage period investigated. Irradiation of the chicken meat samples packaged in high oxygen-permeable film (chicken thigh/AIR and chicken breast/AIR) and in barrier film (chicken thigh/VC, chicken breast/VC, chicken thigh/MA and chicken breast/MA) resulted in a considerable reduction of E.coli, Pseudomonas spp and total enterobacteria counts, however, lactic acid bacteria, yeasts and moulds demonstrated higher resistance in the AIR packaging system. In the samples packaged in barrier film (vacuum and modified atmospere) the lactic acid bacteria were identified as the most resistant to radiation. None of the samples showed growth of Brochothrix thermosphacta and Listeria monocytogenes throughout the storage period investigated. The results of chromatographic analyses of substances generated by lipid degradation showed similar compound profiles for the samples submitted to the three atmosphere conditions studied. In addition, no migration of substances from the packaging material to the meat samples was detected. Irrespective of the packaging system, increasing the radiation dose to levels above 3kGy resulted in the development of a burnt odor the intensity of which increased with increasing dose values, thereby indicating 3kGy to be a recommendable limit that ensures a product with a long shelf-life and without sensory perceptible changes. While the shelf-life of the control samples of chicken thigh/AIR and chicken breast/AIR was estimated at 5 days, irradiation with increasing doses of 1,5 to 7,0 kGy was found to result in a 1,8 to 7,4-fold increase in the shelf-life, respectively. The irradiation process demonstrated to be a potentially very useful tool to extend the shelf-life and improve the quality of chicken cuts
Doutorado
Doutor em Tecnologia de Alimentos

This Master's thesis deals with the strategic analysis of the company KMOTR - Masna Kroměříž a.s. for the period 2009 -- 2013 and a comparison of its results with selected competitors. Consequently there is analysed the sector where KMOTR operates. The thesis is divided into three major parts. The first part deals with the theoretical basis for financial analysis and strategic sector analysis. Another part is focused on the analysis of the production and preserving of meat and meat products and introduction of selected competitors. Last part comprises my own analysis based on public financial statements. In the conclusion there is presented a summary of the most important results and recommendations for improvement of the company situation.

A biodisponibilidade de ferro de diferentes fontes foi avaliada pelo método de recuperação de hemoglobina em suínos anêmicos. O ensaio teve duração de 13 dias e os grupos foram homogeneizados de acordo com o produto do peso (kg) x hemoglobina (g/dL). As fontes de ferro estudadas foram: ferro microencapsulado com polímero de carboximetilcelulose sódica (NaCMC), ferro microencapsulado com polímero de alginato, ferro quelado com metionina e ferro reduzido eletrolíticamente. Com a finalidade de corrigir respostas devidas à variação na ingestão de ferro foram acrescentados três grupos chamados de grupos-padrão, cuja fonte dietética de ferro foi FeSO4.7H2O. A porcentagem média de absorção de ferro para os grupos experimentais variou de 12,8 (4,3) % (ferro eletrolítico) a 15,1 (3,8) % (ferro alginato), não sendo significativamente diferentes (P>0,05). A porcentagem média de absorção relativa ao FeSO4.7H2O variou de 89,5 (25,9)% (ferro NaCMC) a 105,9 (60,5)% (ferro quelado com metionina), sem diferenças significativas (p>0,05). Também não houve diferença significativa nos índices de conversão alimentar, eficiência alimentar e coeficiente de eficácia proteica (CEP). Não houve diferenças significativas (p>0,05) nas concentrações de ferro hepático entre as diferentes fontes estudadas. Nas condições deste ensaio, houve similaridade entre as fontes de ferro testadas quanto à biodisponibilidade. A microencapsulação proporcionou rneltlOr distribuição do produto na mistura quando comparada ao FeSO4.7H2O.
The iron availability from different sources was evaluated by the hemoglobin regeneration method in anemic pigs. The assay took 13 days and the animais were selected according to the weight (kg) x hemoglobina (g/dL) product. The iron sources studied were: microencapsulated iron with sodium carboximetilcelulose polymer (NaCMC), microencapsulated iron with alginato polymer, metionin-quelated iron and electrolytically reduced iron. To COITect answers due to iron ingestion variation three control groups were added, whose dietary iron source was FeSO4.7H2O. The average percentage of iron absorption for the experimental groups ranged from 12,8 (4,3) % (electrolytic iron) to 15,1 (3,8) % (iron alginato), without significant differences (p>0,05). The average percentage of FeSO4.7H2O relative absorption ranged from 89,5 (25.9)% (NaCMC iron) to 105,9 (60,5)% (metionin quelated-iron), without significant differences (p>O,OS). Also it did not have significant difference in the alimentary conversion and efficiency indexes and proteic effectiveness coefficient (CEP). No significant differences (p>0,05) were found in the hepatic iron concentrations among the different studied sources. Based on this assay\'s conditions, there were similarities among the tested iron sources regarding to their bioavailability. Microencapsulation provided better distribution of the product in the mixture when compared to the FeSO4.7H2O.

"Salpicão de Vinhais" and "Chouriça de Vinhais" are traditional dry-fermented smoked meat sausages produced in Vinhais, a small region of Trás-os-Montes. The scientific knowledge of this sausage variety is limited. This work aims to collect scientific data that could, partially, fill the gaps in knowledge regarding these products, analyse the data and develop a risk-based study, according to an internationally accepted framework and finally, to explore the effect of hypothetical risk management measures on the safety of consumers, regarding traditional dry fermented meat smoked sausages. Seventy seven samples of ―Salpicão‖ and ―Chouriça de Vinhais‖ were purchased from producers, local markets and retail stores. Their microbiological and physical chemical characteristics were analyzed. The same analyses were performed on the products during the production processes. The raw materials and ingredients were also analyzed. Regarding the pathogenic flora, Staphylococcus aureus, spores of sulphite-reducing clostridia, Escherichia coli 0157:H7, Yersinia spp. and Salmonella spp., were not detected in any of the samples analyzed; Listeria monocytogenes was detected in 14.3% of the samples. The manufacturing process, namely fermentation, ripening/drying and smoking reduced the numbers of pathogen and hygiene indicator microorganisms. According to the Commission Regulation (EC) 2073/2005, 39% of the contaminated samples of ―Salpicão‖ and ―Chouriça de Vinhais‖ were able to support growth of L. monocytogenes. A quantitative microbiological risk assessment using a probabilistic model was developed. Considering the Portuguese population, with data obtained in this work, the calculated risk of listeriosis, for the intermediate age sub-population was 0.1297 cases per year, for the perinatal sub-population, 1.3695 cases per year, and elderly sub-population 0.1995 cases per year. This means that Traditional Dry Fermented Smoked Sausages constitute a low risk for the Intermediate Age and Elderly population (less than 1 case per annum) and an intermediate risk for the Perinatal populations, considering this last group of consumers as adult pregnant women (1-10 cases per annum). The effect of several putative risk management actions such as the adoption of a Performance Objective of 10 CFU/g, 1 CFU/g and 0.04 CFU/g reduced the risk of listeriosis for all sub-groups, at the end of shelf life, by 25.5%, 58.4% and 58.6%, respectively. The effect of bacteriocinogenic strain of Pediococcus acidilactici HA6111-2, previously isolated from ―alheira‖, was studied on both ―Salpicão‖ and ―Chouriça‖, in a challenge test against a cocktail of Listeria innocua, at pilot scale. A reduction of the numbers of Listeria innocua was achieved in all batches, being the biphasic equation the model that gave the better fit. The use of a bacteriocinogenic strain added to the batter reduced the risk of listeriosis for all sub-groups by 26.7%; obtaining a final product with aw below 0.92, supposedly below the growth limits of L. monocytogenes, reduces the risk by 8.6% in all sub-groups of population; the combination of the bacteriocinogenic strain and the limit of aw 0.92 reduces the risk by 41.0%. Traditional dry fermented smoked sausages present low to medium risk to the health of consumers. The use of more restrictive Performance Objectives during processing and/or distribution will result in a further reduction of risk. A more rigorous control of final product water activity and the use of a bacteriocinogenic bioprotective culture during production may contribute significantly to reducing the risk of listeriosis in consumers of these Traditional Dry Fermented Smoked Sausages (TDFSS).
O Salpicão de Vinhais e a Chouriça de Vinhais são enchidos fermentados, secos e fumados, produzidos em Vinhais, uma pequena região de Trás-os-Montes. Este trabalho pretende recolher dados científicos que possam preencher, ainda que parcialmente, os lapsos no conhecimento deste tipo de produtos, de acordo com uma abordagem aceite internacionalmente e, finalmente, explorar o efeito potencial que as medidas de gestão de risco podem ter na segurança dos consumidores, relativamente a enchidos tradicionais, fermentados, secos e fumados. Setenta e sete amostras de ―Salpicão‖ e ―Chouriça de Vinhais‖ foram compradas em produtores, mercados locais e hipermercados. As suas características microbiológicas e físico-químicas foram analizadas. As mesmas análises foram realizadas ao produto em curso, em diferentes fases do processo produtivo. As matérias-primas e ingredientes também foram analisadas. Relativamente à flora patogénica, não foram detectados esporos de Staphylococcus aureus, esporos do género Clostridia sulfito-redutores, Escherichia. coli 0157:H7, Yersinia spp. e Salmonella spp; Listeria monocytogenes foi detectada em 14.3% das amostras. O processo de fabrico, nomeadamente fermentação, maturação/secagem e fumagem reduziram o número de patogénicos e microrganismos indicadores de higiene. De acordo com o Regulamento da Comissão (CE) 2073/2005, 39% das amostras de ―Salpicão‖ e ―Chouriça de Vinhais‖ contaminadas eram capazes de permitir o crescimento de L. monocytogenes. Foi desenvolvida uma avaliação quantitativa de risco microbiológico. Considerando a população portuguesa, com os dados obtidos neste trabalho, o risco calculado de listeriose seria de 0.1297 casos por ano para a população de idade intermédia, 1.3695 casos por ano para a sub-população perinatal, e 0.1995 casos por ano para a sub-população sénior. Isto significa que Enchidos Tradicionais Secos, Fermentados e Fumados constituem um alimento de baixo risco para para a população de idade intermédia e população sénior (menos de 1 caso por ano) e são um alimento de risco intermédio para a população perinatal, ou seja, mulheres grávidas adultas (entre 1 a 10 casos por ano). A adopção de um Objectivo de ―Performance‖ de atingir 10 UFC/g, 1 UFC/g e 0,04 UFC/g no produto final reduziram o risco de listeriose para todos os sub-grupos da população, em 25.5%, 58.4% e 58.6%, respectivamente. O efeito da estirpe bacteriocinogénica de Pediococcus acidilactici HA6111-2, previamente isolada em alheira, foi estudada tanto no Salpicão como na Chourila de Vinhais, num ―challence test‖ contra um cocktail de Listeria innocua, à escala piloto. Foi observado, em todos os lotes, uma redução dos números de Listeria innocua, abaixo do limite de detecção (1.5 log UFC/g), A equação bifásica foi que forneceu o melhor ajuste da redução dos números de Listeria innocua, devido ao da estirpe bacteriocinogénica de Pediococcus acidilactici HA6111-2. A aplicação de uma estirpe bacteriocinogénica à adoba reduziu o risco de listeriose, em todos os sub-grupos populacionais em 26.7%; obter um produto final com aw inferior a 0.92 reduziu o risco de listeriose, em todos os sub-grupos populacionais em 8.6%; a combinação destes dois factores reduziu o risco de listeriose, em todos os sub-grupos populacionais em 41.0%. Os Enchidos Tradicionais Secos, Fermentados e Fumados apresentam um risco baixo ou médio para a saúde dos consumidores. A aplicação de Objectivos de ―Performance‖ durante o processamento e/ou distribuição resulta numa redução do risco. Um controlo mais rigoroso da actividade de água do produto final e o uso de uma cultura bioprotectiva bacteriocinogenica durante a produção, podem contribuir para reduzir significativamente o risco de listeriose nos consumidores deste tipo de produto tradicional.

Sweet whey powder is mainly used as an ingredient in foods and has a potential for increased use with the development of new foods. In view of the many whey powder producers, there is need to establish the quality of the whey powders currently on the market in terms of conformance to specifications, consistency over different seasons, and keeping quality. Selected sweet whey powder from different processors was analysed for microbiological, physicochemical and sensory quality. The whey powder was in most the cases within specifications. There was suggestive evidence of seasonal variability in the cooked flavor and sweet taste. In regard to storage, there was no significant difference in the flavor and aroma of the whey powder with storage except for the oxidized flavor which was marginally significantly different in at least one product. Most of the variation was in the microbiological and physicochemical properties. Of three products considered, rate of deterioration by the Maillard reaction, one was significantly different from the other two, having lower activation energy. Accelerated shelf-life testing deterioration rates compared well with those at ambient conditions for two products, implying that ASLT can be used for shelf-life determinations only if Maillard reaction inhibitors are absent. The flavor and aroma of sweet Cheddar cheese whey powder from one processor over 12 months, was consistent. However, the physicochemical, and microbiological properties were variable mainly between the fall and summer production with the fall production being higher in L* (lightness) and pH, but low in solubility index, and conversely, the summer production being high in solubility index and titratable acidity but low in L*.
Graduation date: 2005

碩士
國立臺灣大學
食品科技研究所
107
Maillard reaction always occurs during food processing, and produces reactive dicarbonyl species (RDS) and advanced glycation end products (AGEs). According to the research, RDS will increase risk of neurodegenerative disease. The adverse effects of AGEs and their correlation with metabolism syndromes have been obtained much of attention on health researches. To measure the content of RDS and AGEs in commercial processed meat products, the analyses were conducted using liquid chromatography- high resolution mass spectrometry (LC-HRMS). Three RDS and eight AGEs were identified in selected samples from Taiwanese market including glyoxal, methylglyoxal, diacetyl, Nε-carboxymethyllysine (CML), Nε-carboxyethyllysine (CEL), argpyrimidine, pyrraine, glyoxal-lysine dimer (GOLD), methylglyoxal-lysine dimer (MOLD), Nδ-(5-hydro-4-imidazolon-2-yl)ornithine (glyoxal derived hydroimidazolone; G-H1), Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)ornithine (methylglyoxal derived hydroimidazolone; MG-H1). Our research shows that the content of total RDS in commercial processed meat products are in the range of 244 to 3092 ng/g. The AGEs were separated on an Intrada amino acid liquid chromatographic column without derivatization. Only the free forms of CML and CEL were found in the examined samples with much lower content levels. The content of total AGEs in testing products was in the range of 63 to 1833 μg/g. The established analytical platform can be an effective tool for monitoring the distribution of RDS and AGEs in processed meat products as well as in our diet and also a tool for quality control of the food industry.

This study was conducted to determine if alternative heating times and slower cooling times, other than those defined by FSIS, could be utilized and still comply with FSIS performance standards. Large (10.43 to 12.25 kg), cured bone-in hams (n = 190) and large (greater than or equal to 9.07 kg), uncured beef inside rounds (n = 180) were utilized in a two-phase study. Phase 1 of the study investigated the effect of alternative lethality parameters on toxin production of Staphylococcus aureus and log reduction of Salmonella Typhimurium and coliforms. Both the hams and roast beef were subjected to 1 of 10 treatments defined by varying final internal product temperatures (48.9 degrees C, 54.4 degrees C, 60.0 degrees C, 65.6 degrees C, or 71.1 degrees C) and smokehouse relative humidities (50% or 90%). Phase 2 investigated the effect of alternative stabilization parameters on log growth of Clostridium perfringens. Stabilization treatments extended the times taken to reduce internal product temperature from 54.4 degrees C to 26.7 degrees C and from 26.7 degrees C to 7.2 degrees C (ham) or 4.5 degrees C (beef), independently. Further, a control treatment following current FSIS, Appendix B guidelines was conducted for ham, and a "worst case" scenario was assessed for both products. The "worst case" treatment evaluated the effects of cooling products at room temperature (approximately 22.8 degrees C) in place of normal cooling procedures in a temperature controlled environment. Results of the study showed at least a 6.5-log10 reduction in S. Typhimurium across all lethality treatments for both products. Further, coliform counts also were reduced significantly, and S. aureus toxin kits returned negative results for toxin production for all treatments of ham and roast beef. Stabilization showed less than 1-log growth of C. perfringens for any treatment, with the exception of the "worst case" scenario for roast beef. As expected, > 1 log growth of C. perfringens was found for uncured roast beef maintained at room temperature for cooling. This study supports that there are multiple time and temperature combinations, other than those currently provided by FSIS, which may be utilized for cooking and cooling large roast beef and bone-in ham products while still meeting FSIS lethality and stabilization microbiological performance standards.

碩士
國立臺灣師範大學
化學系
105
Heterocyclic aromatic amines (HCAs) comprise of a class of > 25 compounds, which primarily generated unintended hazardous substances by heating or processing of meats from cooking of proteinaceous foods at temperatures above 150℃. In addition, several of them have been found to be carcinogenic in animals, causing tumors in diverse organs across multiple species. The International Agency for Research on Cancer (IARC) has classified three HCAs (MeIQ, MeIQx, and PhIP) as being possible human carcinogens (Group 2B) and one HCA (IQ) to be a probable human carcinogen (Group 2A). In this study, two sample preparation strategies, liquid-liquid extraction (LLE) with solid-phase extraction (SPE) and quick, easy, cheap, effective, rugged, and safe extractions (QuEChERS) method, were investigated for the determination of 11 types of HCAs in meat products by LC-MS/MS. HCAs in sample were first extracted with acetonitrile by LLE, and followed by SPE using Oasis® MCX cartridges. In QuEChERS extraction, acetonitrile is used as LLME solvent, and PSA, C18EC and MgSO4 are served as dSPE sorbent. Both methods showed good performances on precision (RSD < 15.15%), accuracy (79.80-117.64%), recovery (52.39-116.88%), limit of quantitation for the spiked meat extract (0.01-10 ppb) and correlation coefficients (>0.993). QuEChERS extraction strategy gives better linear dynamic range and superior sensitivity in comparison with LLE-SPE approach. Eventually, HCAs were successfully quantified in real samples by two proposed approaches on LC-MS/MS system.

This Mater´s Degree Thesis focuses on the sensory analysis of the chosen products of the non-perishable meat products in the dependence on the production technology. Its aim is to compare what kind of the products is prefered by the consuments using the sensory analysis and then statistic evaluation. The theoretical part summarizes the findings of the sensory analysis of the products, it also includes the conditions of the analysis and the statistic evaluation, sense perception in general and the production technology of meat products. In the practical part is described the method and the results of the hedonic test performed. In the thesis were used for evaluation the samples of the non-perishable meat products of the leading Czech producers of non-perishable meat products distributed and available in the shops in the Czech Republic.

Meat products belong into a popular group of foodstuffs intended for human consumption. Upon cancellation of state standards after 1992 it was possible to register an increase in distribution of products into shopping networks under the same name but with different ingredients. An analysis of the content of basic ingredients and of the sensory quality was carried out on selected samples of heat-treated meat products (20 products, 17 producers) bought in various types of shops. The contents of basic ingredients (water, fat, salt, proteins, collagen) were measured in a laboratory with the help of the NIRFLEX N 500 instrument, and no results of measurement at the level of conclusiveness (p < 0.05) were statistically evidenced. The best evaluation was granted by the assessors (6 persons) to the sample of the "Junior" group from producer "Fleischwaren Berger" from the Billa supermarket, while the worst evaluation belonged to the sample of the "Chicken Junior" group from producer "Schneider Masokombinát Plzeň" from the Albert supermarket.

The main goal of this research was to determine the effectiveness of saturated fat replacement by means of a canola oil oleogel, termed an “organogel”, using ethyl cellulose (EC, 10 cP) as the gelator and sorbitan monostearate (SMS) as a plasticizer. All-beef frankfurters and pork breakfast sausages were used and instrumental tests performed to determine effectiveness were light microscopy, texture profile analysis, Warner-Bratzler shear force, cook loss and smokehouse yield. A trained sensory analysis panel scored for hardness, juiciness, oiliness, and the presence of off flavours. Replacing beef fat (BF) with canola oil (CO) in frankfurters produced a product that was significantly harder (P < 0.05). The gelling of the canola oil lowered the TPA hardness values. Cohesiveness, chewiness and gumminess values were statistically similar to the BF control. Minor changes in L*, a* and b* values were observed, with the organogel frankfurters being lighter than the BF control. Sensory analysis scores showed that 8,10 & 12% EC frankfurters were significantly less hard than the CO control.
Ontario Ministry of Agriculture, Food & Rural Affairs (OMAFRA)

No setor alimentar o controlo da qualidade e o estudo de vida útil são importantes, uma vez que é por meio destes que se conhece se os produtos estão dentro dos padrões exigidos pelo mercado ou não. O presente trabalho teve como principais objetivos o controlo de qualidade e o estudo de vida útil de produtos e revalidação de prazos já existentes, em produtos com carne e com elevadas percentagens de margarina, tendo sido realizado na empresa líder de massas congeladas em Portugal, designadamente na Panike S.A. Na busca por maior qualidade na obtenção de produtos, foi acompanhado e realizado, numa base diária, o controlo de processos em todas as linhas da empresa, nas estações de controlo ao longo das linhas, a análise das amostras de referência e por vezes a receção de farinha. No estudo de vida útil todos os produtos foram submetidos a análises microbiológicas e organoléticas em três pontos diferentes de amostragem. A primeira análise foi realizada no início do estudo, a segunda no fim do teste acelerado de envelhecimento e a ultima no fim do estudo. Ao nível das análises microbiológicas, os valores obtidos foram comparados com os valores guia do INSA, verificando-se que os produtos que foram cozidos antes da análise apresentaram resultados satisfatórios ao nível dos microrganismos a 30ºC enquanto os crus apresentaram resultados não satisfatórios um pouco elevados. Das análises organoléticas efetuadas pelos provadores, concluiu-se que nos produtos de padaria as médias de aceitação foram praticamente idênticas ao longo do estudo, não sofrendo grandes oscilações. Nos produtos de pastelaria o mesmo não aconteceu; nos produtos com recheio de carne notou-se alterações ao longo do estudo, pois foi possível verificar o aparecimento de sabor a ranço. Nos produtos de recheio doce os provadores não notaram maus sabores pelo que as médias de aceitação foram maiores quando comparadas com os produtos de recheio de carne. Nos produtos sem recheio o único produto que manteve as suas propriedades físicas e organoléticas foi o Muffin de Chocolate Cozido. Assim sendo, recomenda-se uma diminuição no tempo de vida útil apenas nos produtos com recheio de carne, e um aumento no Muffin de Chocolate Cozido.
In the food industry quality control and shelf life studies are important to ensure the products eligibility in the market standards. The present work had as main goals the quality control, the study of the products shelf life and the revalidation of existing deadlines in products with meat and with high percentages of margarine. This work was conducted on a leader market frozen dough company in Portugal, the Panike SA. In the quest for higher quality of the finished products, the process control of all production lines, the monitoring stations along the lines, the analysis of reference samples and sometimes reception of flour, was monitored and performed on a daily basis. For the shelf life study, all products underwent microbiological and organoleptic analysis in three different sampling points. The first analysis was performed at the beginning of the study, the second at the end of the accelerated aging test and the last at the end of the study. At the level of microbiological analysis, the values obtained were compared with guide values from INSA, verifying that products that were cooked before analysis showed satisfactory results for the microorganisms level at 30 ° C, while the raw products showed unsatisfactory results. Organoleptic analysis made by the tasters concluded that the bakery products acceptance range were virtually identical throughout the study. As for the pastries, this was not observed; on the products with meat filling we observed changes throughout the study, including the appearance of rancid flavor. On products with sweet filling, the tasters did not report bad taste, meaning that the acceptance averages were higher when compared with the products with meat filling. As for the products without stuffing, the only one that has retained its organoleptic and physical properties, during the whole process was the Baked Chocolate Muffin. Therefore, it is recommended to decrease the shelf life only of products with meat filling, and to increase the muffins baked chocolate shelf life.

Dissertação de mestrado integrado em Engenharia Biológica
A carne apresenta-se como um produto com elevado valor nutricional e, por isso, tem constituído parte da alimentação dos seres humanos ao longo dos tempos. Como produto perecível, a utilização de técnicas de processamento, nomeadamente a secagem e a fumagem, permitiram prolongar o tempo de vida útil deste produto. A empresa Carnes Landeiro destaca-se pela produção de produtos à base de carne, assim como abate e distribuição de carnes de suíno e bovino. Neste momento, a empresa pretende reduzir os preços de venda dos seus produtos, com o intuito de apresentar maior competitividade no mercado. Para tal, realizou alterações no processamento dos produtos, nomeadamente a substituição de matérias-primas, a redução do tempo de secagem e do tempo de fumagem, sem que fosse negligenciada a sua qualidade tanto a nível microbiológico como químico. Para a realização deste trabalho, inicialmente, procedeu-se à escolha de seis produtos (chouriço de vinho, chouriço de carne extra, chouriço de carne tradicional, chouriço crioulo, linguiça e a morcela) que sofreram alterações no ano de 2018, quer na composição das matérias- -primas quer no que respeita aos tempos de processamento. Posteriormente, avaliou-se a sua viabilidade a nível microbiológico e químico, através dos resultados das análises aos produtos. Além disso, foi feito um estudo no que respeita às devoluções e às vendas dos produtos nos dois períodos, isto é antes e após as alterações efetuadas. Deste trabalho conclui-se que, face às alterações na fórmula e no tempo de processamento dos produtos selecionados, os parâmetros foram respeitados, tanto a nível microbiológico como químico. Através da análise dos registos de devoluções verificam-se problemas com o embalamento a vácuo, e ainda, problemas de contaminação na morcela que devem ser corrigidos para evitar a perda e a desconfiança dos clientes. Relativamente às quantidades de vendas, denota-se um aumento em 2018 comparado com o período homólogo de 2017, evidenciando o efeito da redução do preço dos produtos, sem implicações na sua qualidade.
Meat presents itself as a high nutritional value product and, therefore it has been part of the human diet over time. Since it is a perishable product, using processing techniques such as drying and smoking, had allowed its shelf life extension. Carnes Landeiro stands out for the production of meat products, as well as slaughtering and distribution of pork and beef. Nowadays, Carnes Landeiro intends to reduce the selling prices of its products, in order to become more competitive in the marketplace. So, to achieve this goal, it has made some changes in the products processing, namely in the raw materials’ substitution and the reduction of drying and smoking times, without neglecting the product’s quality, both microbiological and chemical. In order to carry out this project Carnes Landeiro chose six products (“chouriço de vinho”, “chouriço de carne extra”, “chouriço de carne tradicional”, “chouriço crioulo”, “linguiça” e a “morcela”) that changed in 2018, both in the composition of the raw materials and in terms of processing times. Afterwards, chemical and microbiological feasibility was evaluated, through the results of the products analysis. Furthermore, to evaluate the returns and sales after and before the changes that have been made, it was conducted a market study. In this way, having in mind all the changes that have been made in the formulations and in the processing time of the selected products, we can concluded that the chemical and microbiological parameters were respected. Through the products’ returns, some problems with the vacuum packaging and also with the “morcela” contamination were verified. All of these problems have to be solved in order to avoid customers’ loss and mistrust. Regarding the products’ sales there is an increase in 2018 compared to the homologous period of 2017, highlighting the effect of the price reduction on the selling products, without implications in its quality.

This diploma thesis deals with sensoric analysis of the selected types of durable meat products depending on the production technology. By sensoric assessment and subsequent statistic analysis, this diploma thesis pursues to compare fermented durable meat products, made without added starting cultures, with fermented durable meat products, made with added starting cultures, and to determine which of these kinds of products are preferred by the evaluators as well as the consumers. The theoretical part of this thesis summarises the conclusions arising from the sensoric analysis of the food, including its conditions and statistical evaluation, sense perception generally and the technology of the production of fermented durable meat products. In the practical part, the applied method and results of the performed twin preference test are described. Samples of the durable meat products of the major domestic producer of the durable meat products, commonly distributed and accessible in the trade network of the Czech Republic, were used for the purpose of evaluation.

Jerusalem artichoke is a root vegetable containing glucofructan inulin in its tubers that is valued for its positive effect on the human organism. The aim of thesis was to evaluate use of meal made from Jerusalem artichoke tubers in production of products from minced meat. The experiment was divided into two parts. In the first part, the differences in water-holding capacity of semi-rough wheat flour and Jerusalem artichoke powder (JAP) in various types of solvents were determined. The statistically significant difference in water-holding capacity between the flours was found solely in the saline solution. Furthermore, the results showed that type of solvent had the main effect on water-holding capacity. In the second part of the experiment, 4 types of meat products were made - sausages, meatloaf, liver pate and meat hash. Wheat flour, which is commonly added to these products, has been completely replaced by (JAP). Subsequently, the sensory analysis was evaluated by experts (n = 16) for an estimation sensory quality and sensory changes of new product with JAP compared to standard meat products. The results of the study showed that the addition JAP to sausages had a negative effect on its sensory quality, namely its overall appearance of the product, texture and taste. On the contrary, there were improved functional properties in meatloaf (juiciness) and pate (taste). According to the results of the sequence test, the liver pate was found the most delicious product.

O consumo de produtos alimentares de origem vegetal em substituição de produtos lácteos tem vindo a aumentar, quer por razões médicas devido à intolerância à lactose e as alergias às proteínas do leite, quer pela adoção de estilos de vida em que dietas alternativas ou vegetarianas/vegans são praticadas por questões relacionadas com a saúde e sustentabilidade. Neste contexto, este trabalho dividiu-se em duas partes: i) caraterização microbiológica, química e biológica de bebida de amêndoa e de dois coprodutos derivados do processamento da amêndoa, nomeadamente o resíduo resultante do fabrico da bebida de amêndoa e o soro resultante da produção de “queijo” de amêndoa tipo fresco; e ii) formulação, produção e caraterização (microbiológica, química e biológica) de bebidas fermentadas à base de soro e de bebida de amêndoa por Bifidobacterium animalis subsp. lactis BB-12 e Streptococcus thermophilus e de cremes para barrar à base de resíduo de amêndoa com e sem incorporação de B. animalis subsp. lactis BB-12. A caracterização microbiológica da bebida e dos coprodutos revelou alguma heterogeneidade nos números de células viáveis dos diferentes grupos microbiológicos analisados. Em termos de composição foi o resíduo de amêndoa que apresentou maior teor de açúcares totais, proteína total e de ácidos gordos totais. A atividade inibidora da α-glucosidase oscilou entre 10-30 % para a bebida e os coprodutos derivados da amêndoa. A hidrólise do resíduo de amêndoa com Viscozyme L permitiu um incremento da capacidade de captura do radical ABTS•+ de 21 vezes relativamente à do resíduo per si, sendo igualmente 5 vezes superior à da bebida e do soro de amêndoa. Todas as matrizes de amêndoa evidenciaram atividade prebiótica, porém o soro, o resíduo na concentração de 4 % (m/v) e o resíduo hidrolisado na concentração de 2 % (m/v), revelaram ser as melhores fontes de carbono alternativas para o crescimento de B. animalis subsp. lactis BB-12. A fermentação das bebidas (soro e bebida de amêndoa 1:1) com B. animalis subsp. lactis BB-12 e S. thermophilus decorreu durante 3,5 e 4,5 h, até se atingir um pH final de 4,5. A fermentação potenciou (9-17 vezes) o aumento da concentração de proteína total, não afetando a capacidade de captura do radical ABTS•+ face às matérias-primas de origem. O creme para barrar pasteurizado (CP) para além de ser composto pelos ácidos gordos presentes na amêndoa, também apresentou teores significativos de ácido láurico e mirístico. Os cremes CP e o creme pasteurizado com probiótico (CPP) foram bem aceites pelos provadores, no que diz respeito à intenção de compra e à intensidade dos atributos organoléticos.
The consumption of plant food products as a substitute for dairy products has been increasing, both for medical reasons due to lactose intolerance and allergies to milk proteins, or due to the adoption of lifestyles where alternative or vegetarian/vegan diets are practiced due to concerns about health and sustainability issues. In this context, this work was divided in two parts: i) microbiological, chemical and biological characterization of almond milk and two co-products derived from the processing of the almond, namely the residue resulting from the manufacture of the almond milk and the serum resulting from the production of fresh-type almond cheese-like product; ii) formulation, production and characterization (microbiological, chemical and biological) of fermented beverages based on serum and almond milk with Bifidobacterium animalis subsp. lactis BB-12 and Streptococcus thermophilus and almond residue spread creams with and without incorporation of B. animalis subsp. lactis BB-12. The microbiological characterization of the almond milk and the co-products revealed some heterogeneity among the viable cell numbers of the different microbial groups analyzed. In terms of characterization, it was the almond residue that presented the highest total sugars, total protein and total fatty acids content. The α-glucosidase inhibitory activity ranged from 10-30 % for the almond milk and almond-derived co-products. The hydrolysis of the almond residue with viscozyme L enabled a 21-fold increase in the ability to capture the ABTS•+ radical against the residue per se and was 5 times higher than that of the almond milk and the serum. All the almond matrices showed prebiotic activity, but the serum, the residue at the concentration of 4 % (w/v) and the hydrolyzed residue at the concentration of 2 % (w/v), proved to be the best alternative carbon sources for the growth of B. animalis subsp. lactis BB-12. The fermentation of the beverages (serum and almond milk 1:1) with B. animalis subsp. lactis BB-12 and S. thermophilus occurred during 3.5 and 4.5 h until a final pH of 4.5 was reached. The fermentation potentiated an increase (9-17 times) in the total protein concentration, without affecting the capturing capacity of the ABTS•+ radical compared to the raw materials. The pasteurized spread cream (CP), besides the characteristic fatty acids present in almonds, also had a high concentration of lauric and myristic acids. The CP cream and the pasteurized probiotic cream (CPP) were well accepted by the tasters in terms of purchase intent and intensity of organoleptic attributes.