Dissertationen zum Thema „Sweet potatoes as feed“

Master of Science
Food Science Institute - Animal Sciences & Industry
Fadi M. Aramouni
Sweet potatoes are a significant crop and are popular among consumers, particularly as french fries. Because the processing steps of making white potato french fries may be detrimental to the quality of a sweet potato fry, it is important to understand the impact of processing on quality and consumer acceptability. The variety of sweet potatoes can affect the texture, appearance, and consumer preference. Peeling processes have evolved from harsh lye treatments to more quick and efficient methods such as steam peeling. Blanching is one of the most important steps because it deactivates enzymes, including polyphenol oxidase and amylases, that affect texture and appearance. While hot water blanching is used by majority of french fry manufacturers, novel techniques like microwave blanching may be similarly effective and less detrimental to the texture and nutritional composition. Time and temperature of the blanching method can affect the texture and flavor by weakening cell walls and leaching sugars. Drying of sweet potato fries prepares the product prior to frying. Drying drives moisture off and allows the starch on the surface of the fries to gelatinize. Many types of dryers, including vacuum, hot air, and fluidized bed, have been evaluated for the rate of moisture loss and final product texture. Drying should not be done too quickly because case hardening will occur and make the product have a tough and chewy bite. Frying uses oil at elevated temperatures to develop color, flavor, and a crispy external texture. The type of oil, oil temperature, and time of frying will affect the finished product attributes. Low oil temperature may lead to higher oil uptake into the sweet potato fries. Vacuum frying compared to deep fat frying can create sweet potato fries with less darkening and less oil uptake, but this method would be difficult in large scale manufacturing. Opportunities in creating high quality sweet potato french fries are directly related to consumer acceptability and manufacturing capability.

Master of Science
Department of Human Nutrition
Weiqun Wang
Anthocyanins may prevent chronic diseases such as cancer and cardiovascular disease, however, the anthocyanin metabolites are not well elucidated. We previously selected a purple-fleshed sweet potato clone P40 that contained anthocyanins at up to 7.5 g/kg dry matter, most of which are cyanidin and peonidin derivatives. The main objective of this study is to identify anthocyanin metabolites in the mice fed 20-30% of purple sweet potato P40 (287 mg and 430 mg peonidin-3-glucoside equivalent /kg body weight) diet for 6 weeks. Plasma, liver, and feces were analyzed for anthocyanin metabolites using HPLC/MS and MALDI-TOF-MS. Fifteen hours after consumption of P40 diet, we identified 4 anthocyanin metabolites cyanidin 3,5- diglucoside; cyanidin 3-sophoroside-5-glucoside; cyanidin3-p-hydroxybenzoylsophroside-5-glucoside; and peonidin 3-p-hydroxybenzoylsophroside-5-glucoside in fecal samples. No anthocyanin metabolites were detected in plasma or liver extracts by HPLC/MS or MALDI-TOF-MS. The results indicate that anthocyanin metabolites in fecal samples might provide health benefits for colonic mucosal cells. However, the lack metabolites in both plasma and liver samples suggest a continuous intake of the anthocyanins may be required for systemic benefits due to their quick degradation and low bioavailability.

Thesis (M. Sc.) (Hons.) -- University of Western Sydney, Hawkesbury, 1997.
Thesis submitted for the degree of Master of Science (Honours), School of Horticulture, University of Western Sydney, Hawkesbury, 1997. In Chapter 1, figures 1.1 and 1.2 are not reproduced in the text. Bibliography : leaves 112-135.

Field experiments were conducted during the 1989 dry season (July to December) at the Manggoapi Farm of the Faculty of Agriculture, Cenderawasih University in Manokwari, Irian Jaya, Indonesia. The objectives of the experiments were to determine the effects of four sweet potato cropping systems on the population density of sweet potato weevils (SPW) and on the diversity of other insects within these agroecosystems.
Fewer SPW were found in intercropped sweet potato + corn (2 weevils per kg infected tubers), sweet potato + soybean (21 weevils), sweet potato + corn + soybean (8 weevils) than in monoculture sweet potato (37 weevils); percentage of damaged tubers followed the same trend, ranging from 2.6% to 14.0% in intercropped sweet potato, to 21.9% in the sweet potato monoculture. However, the higher number of SPW and damaged tubers in the monoculture did not reduce yield below that in the intercropped plots.
Insect and spider populations were more diverse in the intercropped sweet potato systems than in monoculture. Number of arthropods increased throughout the growing season. Intercropping may reduce the population density of other insect pests associated with sweet potato and may increase the population density of natural enemies.

The shelf-life of the sweet potato storage root under tropical marketing conditions limits its potential for marketing. This research aimed to identify the physiological characteristics that affect the shelf-life of sweet potato cultivars when they are exposed to tropical marketing conditions. Weight loss was the key limiting factor in storability under the conditions studied. The range in weight loss was large amongst the 39 cultivars tested, and varied between 5 to 15% per week. Weight loss related to the marketable appearance. It consisted mainly of water loss and only 10% was due to respiratory metabolism. Sweet potatoes with high rates of water loss were more susceptible to rotting. The role of periderm characteristics (thickness and permeability), root-size, root surface area/mass ratio and shape were investigated. Although significant differences were observed among cultivars, these characteristics could not account for the variation in storability. The level of damage severely affected the rates of weight loss, with transpiration rate through damaged areas many times higher than through undamaged periderm. Breakage was found to be the most severe form of damage, having a great impact on weight loss for 14 days. Cultivars differed in susceptibility to damage after standardised damage treatments. Susceptibility to breaks was greater for long thin roots. Skinning injury was negatively related to the periderm thickness. Wound healing ability was a major factor for the shelf-life of sweet potato cultivars. It was demonstrated that lignification of wounds as measured by phloroglucinol staining, correlates with reduced susceptibility to weight loss, water loss and microbial attack. A lignin index was used to express the probability that lignification occurs. Cultivars differed significantly in their lignin indices under tropical marketing conditions. A high dry matter content generally coincided with a low lignin index. This relationship was consistent for 19 cultivars tested. Sensory evaluation of five sweet potato cultivars resulted in five distinct sensory profiles. During storage some of the cultivars lost some of their flavour but little changes were observed for textural properties. It was concluded that changes in sensory aspects are not a limiting factor for storage of sweet potato.

Sweet potato [Ipomoea batatas (L.) Lam] is technically a perennial plant, cultivated and explored as an annual crop. Thus, the identification of the cultivation cycle and sweet potato clones is important for a better utilization of this crop, in both, human and animal nutrition, as for ethanol production. The aim of this work was to evaluate the performance of sweet potato clones grown in different cultivation cycles. The experimental design was a randomized block design, in a split-plot scheme, with three replications. We tested in the plots three cultivation cycles (3, 5 and 7 months), and in the split plots, six sweet potato clones (accessions IBP-007, IBP-038, IBP-075, IBP-079 and IBP-149, and cultivar Brazlândia Rosada). The experiment was carried out at the Research Farm "Campus Rural da UFS", located in the municipality of São Cristovão-SE. The analyzed variables were: survival, damages caused by soil insects, fresh and dry weight of the aerial part, total root yield, content of root dry matter, starch and amylose, and yield of starch and ethanol. All variables were subjected to analysis of variance with the F test, and when significant, the means were compared by the Skott-Knott test at 5% probability. The lowest survival rates occurred in the seventh month of cultivation (51.11%), together with the greatest damage caused by soil insects (4.29), where the clones IPB-038 (2.84), IPB-075 (3.01) and IPB-149 (2.88) showed resistance at the seven month cultivation cycle. Clone IPB-007 presented high values of fresh (14.07 t.ha-1) and dry weight (2.81 t.ha-1) of the aerial part in all the cultivation cycles, presenting also high yield of roots (33.16 t.ha-1), starch (6.63 t.ha-1) and ethanol (4,379 L.ha-1). For content of root dry matter (38.32%) and starch (26.70%), and ethanol yield (176.26 L.t-1), the clone IPB-149 stood out. There was no significant difference in amylose content. The starch content (13.94%) and the yield of roots (7.53 t.ha-1), starch (1.64 t.ha-1) and ethanol (1,034 L.ha-1 and 92.04 L.t-1) were lower for most of the clones evaluated with three months of cultivation. We recommend the use of the cultivation cycle of five months.
A batata-doce [Ipomoea batatas (L.) Lam.] é tecnicamente uma planta perene, plantada e explorada como anual. Sendo assim, a identificação do ciclo de cultivo e de clones de batata-doce é importante para um melhor aproveitamento dessa cultura, tanto na alimentação humana e animal, como para produção de etanol. O objetivo do presente trabalho foi avaliar o desempenho de clones de batata-doce cultivados em diferentes ciclos de cultivo. O delineamento experimental foi o de blocos casualizados, em esquema de parcelas subdivididas, com três repetições. Foram testados nas parcelas três ciclos de cultivo (3, 5 e 7 meses), e nas subparcelas, seis clones de batata-doce (acessos IBP-007, IBP-038, IBP-075, IBP-079 e IBP-149, e a cultivar Brazlândia Rosada). O experimento foi implantado na Fazenda Experimental Campus Rural da UFS , localizada no Município de São Cristovão-SE. As variáveis analisadas foram: sobrevivência, danos causados por insetos de solos, massa fresca e seca de parte aérea, produtividade total de raízes, teor de matéria seca de raiz, amido e amilose e rendimento de amido e etanol. Todas as variáveis foram submetidas à análise de variância com teste F e, quando significativa, as médias foram comparadas pelo teste de Skott-Knott ao nível de 5% de probabilidade. Os menores índices de sobrevivência ocorreram no sétimo mês de cultivo (51,11%), juntamente com os maiores danos causados por insetos de solo (4,29), onde os clones IPB-038 (2,84), IPB-075 (3,01) e IPB-149 (2,88) apresentaram resistência no ciclo com sete meses. O clone IPB-007 apresentou elevados valores de massa fresca (14,07 t.ha-1) e seca (2,81 t.ha-1) de parte aérea, em todos os ciclos de cultivo, apresentando também, alta produtividade de raiz (33,16 t.ha-1), amido (6,63 t.ha-1) e etanol (4.379 L.ha-1). Já para teor de matéria seca de raiz (38,32%) e amido (26,70%) e rendimento de etanol (176,26 em L.t-1), o clone IPB-149 se destacou. Não houve diferença significativa para o teor de amilose. O teor de amido (13,94%) e o rendimento de raiz (7,53 t.ha-1), amido (1,64 t.ha-1), e etanol (1.034 L.ha-1 e 92,04 L.t-1) foram menores para a maioria dos clones avaliados no ciclo com três meses de cultivo. Recomenda-se usar o ciclo de cultivo de cinco meses.

Colorectal cancer is the third leading cause of morbidity and second leading cause for mortality by cancer in the United States. Phytochemicals within fruits and vegetables have demonstrated chemopreventive potential by regulating certain defense mechanisms within the body. This study evaluated consumer acceptability of a sweet potato ginger crisp prototype. Thirty-two male and female subjects (mean age: 22.8 years) were recruited at California State University, Long Beach. Consumer acceptability was significantly (p < 0.05) higher for the commercial product compared to prototype on several sensory attributes. Frequency of consumption was significantly (p < 0.001) higher for the commercial product. The commercial product was preferred overall (91%). Antioxidant capacity measures indicated high radical scavenging (95%) and reducing power (26%) of the prototype. Further research to assess overall quality and marketing the synergistic benefits from the chemopreventive compounds in sweet potatoes and presence of natural sugars may improve its overall acceptability.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
As maltodextrinas sao produtos da hidrolise parcial do amido e tem sido largamente usadas nas industrias de alimentos em muitos tipos de alimentos processados. Maltodextrinas sao classificadas de acordo com o grau de hidrolise do amido, que e expressa em dextrose equivalente (DE). Varias propriedades funcionais, como docura, solubilidade e viscosidade variam de acordo com a degradacao enzimatica e a fonte botanica do amido, e somente a caracterizacao pela dextrose equivalente (DE) se tornou inadequada para orientar a utilizacao das maltodextrinas em varias aplicacoes. Levando em consideracao a importancia das maltodextrinas para o mercado de alimentos, o presente trabalho teve como objetivo realizar estudos sobre o processo de producao e o comportamento das maltodextrinas de mandioca e batata-doce e tambem de compara-las com produtos comerciais. Os amidos das referidas tuberosas foram analisados quanto as suas caracteristicas fisico-quimicas, difracao de raios-X e microscopia optica e eletronica de varredura. Suspensoes de amidos de mandioca e batata-doce, a concentracao de 30%, foram submetidas a hidrolise enzimatica pela enzima ¿-amilase em um reator a diferentes tempos de hidrolise e diferentes niveis de agitacao. Em seguida, foram secas em gspray dryerh e analisadas quanto as suas propriedades fisicas e quimicas, funcionais, reologicas e por difracao de raios-X, alem de serem observadas em microscopio eletronico de varredura. A analise das variaveis do processo indicou maior influencia do tempo de hidrolise na dextrose equivalente (DE) das maltodextrinas de mandioca e batata-doce, sendo que a interacao, tempo de hidrolise e agitacao influenciou na sua solubilidade e viscosidade. As maltodextrinas de mandioca e batata-doce apresentaram DE que variaram de 5,5 a 11,3 e 17,0 a 22,9, respectivamente. As maltodextrinas apresentaram alta solubilidade em...
Maltodextrins are obtained from partial hydrolysis of the starch, and have been widely used in industries due to their broad usage in processed food. Maltodextrins are classified by degree of hydrolysis of starch, which is expressed by dextrose equivalent (DE). Many of their functional properties, like sweetness, solubility and viscosity vary according to enzymatic degradation and botanic source of the starch. Due to the wide uses, dextrose equivalent becomes inadequate to predict the efficiency of maltodextrins in many applications. Considering the importance of maltrodextrins for the food market, the objective of this work was to study the production process and the behavior of cassava and sweet potato maltodextrins, as well as compare them with commercial products. Starches of each tuber were analyzed as to their physiochemical characteristics, X-ray diffraction and optic and scanning electron microscopy. Cassava and sweet potato starches suspensions at 30% concentration underwent enzymatic hydrolysis by an á-amylase enzyme in a reactor considering different times of hydrolysis and levels of agitation. Next, starches were spray dried and analyzed as to their physiochemical, functional, rheological properties and X-ray diffraction, as well as scanning electron microscopy observation. Process variables analysis indicated higher influence of the hydrolysis time in the dextrose equivalent (DE) of sweet potato and cassava maltodextrins, the interaction of between hydrolysis time and agitation influencing in the solubility and viscosity. Cassava and sweet-potato maltodextrins presented DE varying from 5.5 to 11.3 and 17.0 to 22.9, respectively. Maltodextrins presented water solubility in all studied conditions and viscosity was influenced by the hydrolysis level and concentration of the solution. A Newton behavior has been observed in cassava and sweet potato maltodextrins... (Complete abstract click electronic access below)

The sweet potato (Ipomoea batatas L.) is a dicotyledonous species of Convolvulaceae family, cultivated worldwide, with a low production cost and high economic return. Can be utilized in food and feed and ethanol production. The present study aimed, morphological, agronomic and biochemical characterization of sweet potato from the Active Germplasm Bank of UFS access. The experiment was conducted at the Experimental Farm " Rural Campus " UFS, located in the municipality of São Cristóvão - SE, using a randomized block design with 73 treatments (accessions of sweet potato), and two repetitions. In morpho-agronomic characterization it was found that descriptors sheet provided the variability among accessions. It was also observed that most accessions showed resistance to soil insects. The fresh and dry weight of shoots showed results ranging from 0,45 t ha-1 to 12,16 t ha-1 and 0,17 t ha-1 to 2,71 t ha-1, respectively. For total root yield variable, the values ranged from 1,20 to 10,89 t ha-1. The accessions showed excellent results for the dry root mass averaging 30,77 %. The starch content varied between 11,56 and 27,07 % , the yield of starch per hectare ranged from 0,30 to 2,39 t ha-1 and amylose content showed values between 11,57 to 32,72 %. While the ethanol yield in L ha-1 ranged from 198-1576 L h-1, the ethanol yield on L t-1 had an average of 142,67 L t-1. The results showed that the Active Germplasm Bank of UFS presents a wide phenotypic and genotypic variability, with different skills.
A batata-doce (Ipomoea batatas L.) é uma espécie dicotiledônea da família Convolvulaceae, cultivada em todo o mundo, apresentando um baixo custo de produção e retorno econômico elevado. Pode ser aproveitada na alimentação humana e animal e na produção de etanol. O presente trabalho teve como objetivo, a caracterização morfológica, agronômica e bioquímica de acessos de batata-doce do Banco Ativo de Germoplasma da UFS. O experimento foi conduzido na Fazenda Experimental Campus Rural da UFS, localizada no município de São Cristovão SE, utilizando o delineamento em blocos casualizados, com 73 tratamentos (acessos de batata-doce), e duas repetições. Na caracterização morfo-agronômica verificou-se que os descritores de folha proporcionaram a variabilidade entre os acessos. Observou-se também que a maioria dos acessos apresentou resistência a insetos de solo. A massa fresca e seca de parte aérea apresentou resultados variando de 0,45 t ha-1 a 12,16 t ha-1 e 0,17 t ha-1 a 2,71 t ha-1, respectivamente. Para a variável produtividade total de raízes, os valores variaram de 1,20 a 10,89 t ha-1. Os acessos demonstraram resultados excelentes para o teor de massa seca de raiz com média de 30,77%. O teor de amido variou entre 11,56 e 27,07%, o rendimento de amido por hectare ficou entre 0,30 a 2,39 t ha-1 e o teor de amilose apresentou valores entre 11,57 a 32,72 %. Enquanto que o rendimento de etanol em L ha-1 variou entre 198 a 1.576 L ha-1, o rendimento de etanol em L t-1 apresentou média de 142,67 L t-1. Os resultados mostraram que o Banco Ativo de Germoplasma da UFS apresenta uma grande variabilidade fenotípica e genotípica, com diferentes aptidões.

Sweet potato feathery mottle virus (SPFMV) (Potyvirus genus, Potyviridae family) causes important yield losses in sweet potato crops, in particular in co-infections with the unrelated crinivirus Sweet potato chlorotic stunt virus (SPCSV). This thesis addresses the characterization of some novel aspects in the infectious cycle of SPFMV, such as the expression, production and function of a new gene product named P1N-PISPO. A better understanding of SPFMV genome organization and the functions of their gene products might be relevant to improve the control strategies against this virus and the associated diseases in sweet potato crops. The positive-sense RNA genome of SPFMV contains a large ORF, translatable as a polyprotein yielding a set of functional mature gene products (P1, HCPro, P3, 6K1, CI, 6K2, VPg-Nla, Nlb and CP), and a short ORF named PIPO in the -1 frame, embedded within the P3 region. In addition to this organization, common to all the members of the Potyvirus genus, another ORF named PISPO was predicted in the genome. PISPO is in the -1 frame within the P1 region of SPFMV and other related potyviruses, starting at a conserved G1_2A6_7 motif, similar to the motif found upstream of PIPO. The expression of PISPO during SPFMV viral infection could result in the production of a putative new gene product P1N-PISPO. In the present work, the presence of the PISPO frame has been investigated in a Spanish isolate of SPFMV infecting Ipomoea batata plants. The genome sequence of this isolate has been assembled from NGS data, showing that the expected trans-framed PISPO sequences is present, preceded by a G2A6 motif. A specific analysis of the NGS data has revealed a significant proportion of transcripts with an extra A in the motif at the beginning of PISPO, as well as a lower proportion of transcripts with an extra in the corresponding conserved motif preceding the PIPO region. These results have demonstrated that a polymerase slippage mechanism could generate transcripts containing extra A residues (G2A7) to allow the translation of P1N-PISPO and P3N-PIPO gene products. Analysis of the viral gene products present in SPFMV infected plant tissues has been performed using LC-MS/MS after separation in SDS- PAGE, focusing in products > 50KDa. Peptides corresponding to the P1 protein have been detected from both the N-terminal portion (11 different peptides, 39% coverage), before the frameshifting signal and therefore common for P1 and P1N-PISPO, and in the C- terminal part (2 peptides exclusive for P1, 10% coverage). Interestingly, four peptides exclusive of PISPO, in its unique ORF (21.3% coverage), have been also found. These results have confirmed that both products P1 and P1N-PISPO are expressed and coexisted during SPFMV infection. Furthermore, transient expression of SPFMV gene products coagroinfiltrated with a reporter gene in Nicotiana benthamiana have revealed that P1N-PISPO acts as an RNA silencing suppressor, a role normally associated with HCPro in other potyviruses. Moreover, mutation of WG/GW motifs present in P1N-PISPO abolished its silencing suppression activity, suggesting that the function might require interaction with Argonaute components of the silencing machinery, as was shown for other viral suppressors. Altogether, the results of this thesis have confirmed the expression of P1N-PISPO during SPFMV infection and they have revealed a polymerase slippage mechanism as the responsible of P1N-PISPO production. Our results also have demonstrated the role of P1N-PISPO as a RNA silencing suppressor.
El virus Sweet potato feathery mottle virus (SPFMV) (Gènere Potyvirus, Família Potyviridae) presenta un genoma de cadena senzilla i positiva de ARN que conté una pauta de lectura oberta (ORF), traduïda com una poliproteïna que dóna lloc a un conjunt de productes gènics madurs, i una ORF curta anomenada PIPO que es troba en el marc de lectura -1 de la regió P3 de la poliproteïna. A més a més, en el seu genoma s'ha observat una ORF addicional anomenada PISPO. PISPO es troba en el marc de lectura -1 dins de la regió gènica de la P1 en SPFMV i els potyvirus més propers, començant en el motiu conservat G 1_2A6_7 i similar al motiu d'inici de PIPO. La expressió de PISPO durant la infecció del virus donaria lloc a la producció del hipotètic producte gènic P1N-PISPO. La presència de la pauta de lectura PISPO, precedida per un motiu G2A6, ha estat confirmada en un aïllat Espanyol de SPFMV. L'anàlisi de dades obtingudes per seqüenciació massiva, ha permès identificar una proporció significativa de transcrits que contenen una A extra en el motiu al començament de PISPO, així com una proporció menor de transcrits amb aquesta A extra en el motiu de PIPO. Aquests resultats han demostrat que un mecanisme d'edició de la polimerasa podria generar transcrits amb residus A extra (G2A7), els quals permetrien la traducció dels productes gènics P1N-PISPO i P3N-PIPO. L'anàlisi del productes gènics virals presents en teixits de plantes infectades amb SPFMV s'ha dut a terme mitjançant un experiment de LC-MS/MS. Pèptids corresponents a la part N-terminal de la proteïna P1 (abans del motiu d'edició) han estat detectats, així com pèptids exclusius de la part C-terminal de la P1 i de la pauta de lectura de PISPO. Aquests resultats han confirmat que tant P1 com P1N-PISPO són expressats i co-existeixen durant la infecció de SPFMV. L'expressió transitòria de productes gènics de SPFMV coagroinfiltrats amb un gen reporter en Nicotiana benthamiana ha revelat que P1N-PISPO actua com a supressor de silenciament d'ARN, un rol associat normalment a HCPro en altres potyvirus. Per últim, la mutació de motius WG/GW presents en P1N-PISPO aboleix la seva activitat com a supressor, suggerint que la funció pot està lligada a la interacció amb les proteïnes Argonauta de la maquinària de silenciament, tal i com passa en altres supressors virals.

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Resumo: As maltodextrinas sao produtos da hidrolise parcial do amido e tem sido largamente usadas nas industrias de alimentos em muitos tipos de alimentos processados. Maltodextrinas sao classificadas de acordo com o grau de hidrolise do amido, que e expressa em dextrose equivalente (DE). Varias propriedades funcionais, como docura, solubilidade e viscosidade variam de acordo com a degradacao enzimatica e a fonte botanica do amido, e somente a caracterizacao pela dextrose equivalente (DE) se tornou inadequada para orientar a utilizacao das maltodextrinas em varias aplicacoes. Levando em consideracao a importancia das maltodextrinas para o mercado de alimentos, o presente trabalho teve como objetivo realizar estudos sobre o processo de producao e o comportamento das maltodextrinas de mandioca e batata-doce e tambem de compara-las com produtos comerciais. Os amidos das referidas tuberosas foram analisados quanto as suas caracteristicas fisico-quimicas, difracao de raios-X e microscopia optica e eletronica de varredura. Suspensoes de amidos de mandioca e batata-doce, a concentracao de 30%, foram submetidas a hidrolise enzimatica pela enzima ¿-amilase em um reator a diferentes tempos de hidrolise e diferentes niveis de agitacao. Em seguida, foram secas em gspray dryerh e analisadas quanto as suas propriedades fisicas e quimicas, funcionais, reologicas e por difracao de raios-X, alem de serem observadas em microscopio eletronico de varredura. A analise das variaveis do processo indicou maior influencia do tempo de hidrolise na dextrose equivalente (DE) das maltodextrinas de mandioca e batata-doce, sendo que a interacao, tempo de hidrolise e agitacao influenciou na sua solubilidade e viscosidade. As maltodextrinas de mandioca e batata-doce apresentaram DE que variaram de 5,5 a 11,3 e 17,0 a 22,9, respectivamente. As maltodextrinas apresentaram alta solubilidade em... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Maltodextrins are obtained from partial hydrolysis of the starch, and have been widely used in industries due to their broad usage in processed food. Maltodextrins are classified by degree of hydrolysis of starch, which is expressed by dextrose equivalent (DE). Many of their functional properties, like sweetness, solubility and viscosity vary according to enzymatic degradation and botanic source of the starch. Due to the wide uses, dextrose equivalent becomes inadequate to predict the efficiency of maltodextrins in many applications. Considering the importance of maltrodextrins for the food market, the objective of this work was to study the production process and the behavior of cassava and sweet potato maltodextrins, as well as compare them with commercial products. Starches of each tuber were analyzed as to their physiochemical characteristics, X-ray diffraction and optic and scanning electron microscopy. Cassava and sweet potato starches suspensions at 30% concentration underwent enzymatic hydrolysis by an á-amylase enzyme in a reactor considering different times of hydrolysis and levels of agitation. Next, starches were spray dried and analyzed as to their physiochemical, functional, rheological properties and X-ray diffraction, as well as scanning electron microscopy observation. Process variables analysis indicated higher influence of the hydrolysis time in the dextrose equivalent (DE) of sweet potato and cassava maltodextrins, the interaction of between hydrolysis time and agitation influencing in the solubility and viscosity. Cassava and sweet-potato maltodextrins presented DE varying from 5.5 to 11.3 and 17.0 to 22.9, respectively. Maltodextrins presented water solubility in all studied conditions and viscosity was influenced by the hydrolysis level and concentration of the solution. A Newton behavior has been observed in cassava and sweet potato maltodextrins... (Complete abstract click electronic access below)
Doutor

Master of Science
Department of Animal Sciences and Industry
Teresa L. Slough
Teresa L. Slough
There is increasing interest in the use of point-of-care glucometers to monitor glucose concentrations in horses with metabolic disorders. The first study reported herein compared equine glucose concentrations obtained by a handheld glucometer using whole blood or plasma, a YSI 2300 bench top glucose analyzer using whole blood or plasma, and a SEVEN continuous glucose monitoring (CGM) device that measured glucose in interstitial fluid to readings obtained by a standard laboratory glucose analyzer utilizing plasma. In addition, glucose concentrations obtained by the CGM were compared to those obtained by the handheld glucometer using whole blood or plasma. Post-prandial increases and decreases in glucose concentrations were detected utilizing all glucometers tested. When glucose measurements obtained with the CGM in interstitial fluid were compared to glucose measured using the handheld glucometer in plasma or whole blood, glucose measurements from plasma had better reproducibility. Although the CGM could be a useful instrument for collecting nearly continuous data for the researcher and clinician, there are technical difficulties related to the CGM that must first be overcome. The second study was designed to compare the effects of consuming a twice-daily meal of sweet feed (SF) to ad libitum access to a molasses-based block (BL) supplement on patterns of interstitial glucose concentrations in horses. A novelty effect of the BL was observed, in which horses consumed increased quantities in the first 12 h. Treatments had no effect on intake of forage in this study. The range and means of glucose values were similar between treatments, and significant glucose responses to treatments had lag times that were indirectly similar, even though molasses intake was greater for horses on BL. Variability between horses was noted in quantity of BL consumed as well as timing and magnitude of glucose responses. Based on the results of this experiment, there does not appear to be a clear advantage to either treatment, SF or BL, in attenuating post-prandial glucose increases or in minimizing glucose fluctuations in the horse.

This study was to evaluate the nutritional characteristics of silage sweet potato shoots. The study was conducted at the Federal University of Sergipe (UFS), municipality of Saint Kitts UP. The experimental design was completely randomized with four replications, seven levels of additives (0,5,10,15,20,25,30%), divided into mini-laboratory silos. The dry matter with increased according to increasing levels of additive. The protein showed a decrease in values depending on the levels, probably by protein additive. The neutral detergent fiber and acid detergent fiber, no significant differences (P> 0.05), however, these values were higher in silage without aditivo.O pH and NH3-N of silage obtained ranged from 3.31 and 2.84 to 3.89% to 3.91%. The silage from sweet potato vines had good energy and protein levels and adequate fermentation profile therefore concluded that the use of 15% of this additive in silage showed a better result
Objetivou-se avaliar características nutricionais da silagem da rama da batata doce (Ipomoea batatas) emurchecida e acrescentada com aditivo. O trabalho foi realizado na Universidade Federal de Sergipe (UFS), município de São Cristóvão-SE. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições, sete níveis de aditivos (0,5,10,15,20,25,30%), distribuídos em mini-silos laboratoriais. A matéria seca aumentou de acordo com a elevação do nível de aditivo. A proteína bruta apresentou diminuição nos valores em função dos níveis, provavelmente pelo teor de proteína do aditivo. A fibra em detergente neutro e fibra em detergente ácido, não apresentaram diferenças significativas (P>0,05), porém, estes valores apresentaram-se maiores na silagem sem aditivo.O pH e o N-NH3 da silagem obtidos variaram de 3,31 a 3,89 e 2,84% a 3,91%. As silagens das ramas de batata-doce apresentaram bons teores protéicos e energéticos e adequado perfil fermentativo, portanto, concluiu-se que a utilização de 15% de aditivo na presente silagem apresentou melhor resultado.

Due to the need to define a dose of nitrogen agronomic and economically suitable for the cultivation of sweet potato in the state of Sergipe. The aim of this study was to evaluate the root yield, starch and ethanol in sweet potato clones analyzed from nitrogen. The study was conducted between the months of March and August 2012 at the Experimental Farm |Campus Rural da UFS|, located in the municipality of São Cristóvão, Sergipe, Brazil. We used a randomized complete block randomized in a 5x3 factorial design with three replications, testing five N rates (0, 30, 60, 120 and 240 kg ha-1), using as a source of N as urea (45 % N), and three clones of sweet potato (Brazlândia Branca, IPB-075 and IPB-149). The commercial cultivar Brazlândia Branca was considered as a witness. The crop was harvested at 150 days after planting, by quantifying the total biomass productivity and roots, the dry matter content of the roots, the total dry mass and root biomass, nitrogen content in biomass and roots, the crude protein content in biomass and roots, the accumulation of nitrogen in the biomass of shoots and roots, harvest index, physiological efficiency, efficiency in production of tuberous roots, the recovery efficiency of the utilization efficiency nitrogen, starch content, the starch and yield of ethanol. All clones in this study reached values higher than the national average yield of root yield (11,84 Mg ha-1). The productivity of the aboveground biomass of clones, respond to levels above the levels of nitrogen applied in the present study. A dose of approximately 130 kg ha-1 nitrogen provides maximum yields of total productivity of the tuberous roots of sweet potato clones. The physiological efficiency of recovery of nitrogen applied to the N utilization and efficiency of storage root production decreased with increasing doses of N applied to all sweet potato clones evaluated, whereas the accumulation of N in shoots and tuberous roots of clones IPB-149 and IPB-075 showed significant increases. The dose of 154 kg ha-1 N promotes greater production of total dry matter in storage roots of sweet potato clones. Clone sweet potato IPB-149 showed higher correlation between the use of nitrogen and root yield. With a dose between 120 and 210 kg ha-1 of nitrogen as urea can obtain maximum yields of starch and ethanol in the culture of sweet potato.
Devido à necessidade de definir uma dose de nitrogênio agronômica e economicamente adequada para a cultura da batata-doce no estado de Sergipe. O objetivo deste estudo foi avaliar a produtividade de raízes tuberosas, amido e etanol em clones de batata-doce, analisadas a partir de doses de nitrogênio. O trabalho foi conduzido, entre os meses de março e agosto de 2012, na Fazenda Experimental Campus Rural da UFS , localizado no município de São Cristóvão, Sergipe, Brasil. Foi utilizado o delineamento experimental de blocos casualizados, em esquema fatorial 5x3, com três repetições, testando cinco doses de N (0; 30; 60; 120 e 240 kg ha-1), empregando-se como fonte de N a ureia (45% N), e três clones de batata-doce (Brazlândia Branca; IPB-075 e IPB-149). A cultivar comercial Brazlândia Branca foi considerada como testemunha. A colheita foi realizada aos 150 dias após o plantio, quantificando-se a produtividade total de biomassa e raízes, o teor de matéria seca das raízes, a massa seca total de biomassa e raízes, o teor de nitrogênio na biomassa e nas raízes, o teor de proteína bruta na biomassa e nas raízes, o acúmulo de nitrogênio na biomassa da parte aérea e nas raízes, o índice de colheita, a eficiência fisiológica, a eficiência na produção de raízes tuberosas, a eficiência de recuperação, a eficiência de utilização do nitrogênio, o teor de amido, o rendimento de amido e de etanol. Todos os clones avaliados neste estudo alcançaram valores superiores ao rendimento médio nacional de produtividade de raízes tuberosas (11,84 Mg ha-1). A produtividade da biomassa da parte aérea dos clones avaliados, respondem a níveis acima das doses de nitrogênio aplicadas no presente estudo. A dose de aproximadamente 130 kg ha-1 de nitrogênio proporciona rendimentos máximos de produtividade total de raízes tuberosas pelos clones de batata-doce. A eficiência fisiológica, de recuperação do nitrogênio aplicado, a de utilização do N e a eficiência de produção de raízes tuberosas diminuíram com o aumento das doses de N aplicadas, para todos os clones de batata-doce avaliados, enquanto que, o acúmulo de N na parte aérea e nas raízes tuberosas dos clones IPB-075 e IPB-149 apresentaram incrementos significativos. A dose de 154 kg ha-1 de N favorece a maior produção de massa seca total de raízes tuberosas nos clones de batatadoce. O clone de batata-doce IPB-149 proporcionou maior correlação entre o uso de nitrogênio e a produtividade de raízes. Com a dose entre 120 e 210 kg ha-1 de nitrogênio na forma de ureia pode-se obter rendimentos máximos de amido e de etanol na cultura da batatadoce.

O presente trabalho foi realizado objetivando avaliar o desempenho, característica de carcaça e análise econômica de cordeiros Santa Inês confinados alimentados com silagens de forrageiras alternativas. Foram utilizados quinze cordeiros da raça Santa Inês com idade média de três meses, não castrados e com peso vivo médio inicial de 18,7 ± 5,8 kg, sendo distribuídos aleatoriamente em seus respectivos tratamentos, os quais foram: silagem de milho (SM); silagem de Capim-elefante com 15% de fubá de milho (SC); silagem de parte aérea de batata com 15% de fubá de milho (SRB). Isto é, três tratamentos com cinco repetições, dispostos em um delineamento em bloco completamente casualizado. Observou-se que os animais alimentados com silagem de milho e com parte aérea de batata como fontes de volumosos tiveram os maiores ganhos de peso diário. Os animais que receberam como volumoso a silagem de milho apresentaram maiores valores de rendimento de carcaça quente e rendimento de carcaça fria, 45% e 44,40% respectivamente. Observou-se também, no presente trabalho, em valor absoluto, maior rendimento verdadeiro (55,06%) para os animais alimentados com silagem de milho devido a haver uma relação direta com maior peso absoluto de carcaça quente. Para os parâmetros econômicos da margem bruta e margem líquida pode se observar que o tratamento com silagem de parte aérea de batata apresentou os melhores resultados, embora negativos. O comprometimento da receita com alimentação foi menor no tratamento com parte aérea de batata. A parte aérea de batata e o capim-elefante proporcionam bons resultados em termos de desempenho, características de carcaça e cortes cárneos.

Experimentos com vista à avaliação das propriedades físico-quimica, fitoquímicas e biológica, bem como a sua estabilidade, em raízes tuberosas maduras, caules e folhas jovens de duas cultivares, RBS Amélia e RBS Cuia, e dois acessos de Ipomoea batatas, um de polpa púrpura com manchas brancas (C) e outro de polpa púrpura (D), cultivados ecologicamente e em condições de sequeiro na Horta Comunitária de Lomba do Pinheiro (30º 06’ 46’’ S; 51º 06’ 34’’ O) no Município de Porto alegre, RS no período de 2013 a 2015 foram efetuados nos laboratórios de Higiene, Qualidade e Microbiologia de alimentos e de Química e Bromatologia do Instituto de Ciência e Tecnologia de Alimento (ICTA) da Universidade Federal do Rio Grande do Sul (UFRGS). A avaliação quantita-tiva das propriedades físico-químicas e fitoquímicas seguiu os métodos descritos no Manual das Normas Técnicas para Determinação das Propriedades Físico-químicas em alimentos do Instituto Adolfo Lutz. O teor de polifenóis totais foi determinado pelo método de Folin & Ciocalteu, o con-teúdo de antocianinas pelo método de pH diferencial, os flavonoides, taninos e vitamina C avalia-dos por métodos espectrofotométricos. A atividade biológica consistiu na determinação das pro-priedades antioxidantes dos materiais usando o método fotocolorimétrico in vitro, empregando o radical livre estável 2,2-difenil-1-picrilhidrazila (DPPH) e na avaliação da atividade antimicrobi-ana, expressa como intensidade de atividade de inibição bacteriana (IINIB) e intensidade de ativi-dade de inativação bacteriana (IINAB), usando sistema de tubos múltiplos frente a diferentes con-centrações de Salmonella Enteritidis (ATCC 11076), Enterococcus faecalis (ATCC 19433), Es-cherichia coli (ATCC 11229) e Staphylococcus aureus (ATCC 25923). Foi igualmente analisada a estabilidade físico-química, fitoquímica e biológica das raízes tuberosas, caules e folhas estoca-dos a temperatura ambiente por períodos de 90, 180 e 270 dias, através da mensuração e avaliação das concentrações dos componentes físico-químicos, fitoquímicos e atividade biológica naqueles pontos de estocagem, Foram encontrados teores de proteínas variando de 10,5 a 26,3%, carboidra-tos totais oscilando de 15,7 a 61,1% com valores altos observados na cultiva RBS Amélia. Maiores teores de fenólicos totais e antocianinas foram observados em acessos de polpa púrpura com valo-res até 709,3 e 78,7mg/100g, respectivamente. Elevada atividade antioxidante foi também verifi-cada na maioria dos extratos testados que, igualmente, evidenciaram atividade antibacteriana frente a todos os inóculos testados ainda que a sua intensidade tenha sido diferente. Porém, nenhuma atividade antibacteriana foi verificada em extratos preparados com base no calor, quais sejam in-fusão e decocção. A estabilidade das propriedades de todos esses materiais foi presenciada embora algumas características tenham reduzido seus teores aos 270 dias de estocagem. O trabalho conclui que as raízes tuberosas, caules e folhas das cultivares RBS Amélia e RBS Cuia e dos acessos de batata-doce estudados se constituem em hortaliças vegetais com alto potencial físico-químico, fi-toquímico e biológico, a avaliar pelos altos teores de carboidratos totais, considerável concentração de proteínas, elevados valores de polifenóis totais e, ou antocianinas, principalmente nos acessos de polpa púrpura. Os mesmos materiais têm um indicativo de atividade antioxidante e de atividade antibacteriana seletiva frente a Salmonella Enteritidis (ATCC 11076), Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229) e Staphylococcus aureus (ATCC 25923). Figuram-se, portanto, como uma excelente fonte de proteína, carboidratos e de compostos fenólicos relativamente estável por período de 270 dias de estocagem a temperatura ambiente, tornando-se importante na segurança alimentar e nutricional, saúde e bem-estar social.
Experiments for the evaluation of the physic-chemical, phytochemical and biological properties, and their stability in mature tuber roots, young stems and leaves of two cultivars, RBS Amelia and RBS Cuia and of two accessions of Ipomoea batatas, one having purple fleshed tuber roots with white spots (C) and another purple fleshed tuber (D), grown ecologically in “ Horta Comunitária da Lomba do Pinheiro (30º 06' 46'' S, 51° 06' 34'' O), Porto alegre, RS from the period of 2013 to 2015 were perfomed in the Hygiene, Quality and Microbiology and Food Chemistry laboratories of the Institute of Science and food Technology (ICTA), Federal University of Rio Grande do Sul (UFRGS). The quantitative assessment of physicochemical and phytochemical properties followed the described methods in the Manual of Technical Standards for Determination of Physical and Chemical Properties, Institute Adolfo Lutz. The total polyphenol content was determined by the Folin & Ciocalteu method, the content of anthocyanins at pH differential method, flavonoids, tan-nins, and vitamin C evaluated by spectrophotometric methods. Biological activity was analysed evaluated by determinating antioxidant properties of materials using fotocolorimétrico in vitro method, using the stable free radical 2,2-diphenyl-1-picrilhidrazila (DPPH) and also by evaluating antimicrobial activity, expressed as intensity of bacterial inhibition activity (IINIB) and intensity of bacterial inactivation activity (IINAB) using multiple tube system against different concentra-tions of Salmonella enteritidis (ATCC 11076), Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229) and Staphylococcus aureus (ATCC 25923). It was also analyzed the physical and chemical, phytochemical and biological stability of tuber roots, stems and leaves stored at room temperature for periods of 90, 180 and 270 days, through the measurement and assessment of con-centrations of physico-chemical components, phytochemicals and biological activity on those points of storage. Protein levels were found ranging from 10.5 to 26.3%, total carbohydrates rang-ing from 15.7 to 61.1% with higher values observed in the RBS Amelia cultivar. Higher total phe-nolic content and anthocyanins were found in the purple fleshed roos, with values of up to 709.3 and 78,7mg / 100g, respectively. High anti-oxidant activity was also observed in most of the tested extracts which also showed antibacterial activity against all inocula tested, although its intensity was different. However, no antibacterial activity was detected in extracts prepared by heat, namely infusion and decoction. The stability of the properties of all materials was attended although some features have reduced its contents to 270 days of storage. The paper concludes that the tuber roots, stems and leaves of the RBS Amélia and RBS Cuia cultivars and sweet potato accessions studied constitute vegetables with high physical-chemical, phytochemical and biological potential, accord-ing to the high levels of total carbohidrates, considerable protein concentration, high total polyphe-nol values, or anthocyanins, mainly in pupuple fleshed roots accesses. The same materials have an indicative of antioxidant activity and selective antibacterial activity against Salmonella enteritidis (ATCC 11076), Enterococcus faecalis (ATCC 19433), Escherichia coli (ATCC 11229) and Sta-Staphylococcus aureus (ATCC 25923). Therefore, this specie can be seen as an excellent source of protein, carbohydrates and relatively stable phenolic compounds for a period of 270 days of storage at room temperature, making it important for food security and nutrition, health and social welfare.

O presente trabalho foi realizado objetivando avaliar a qualidade das silagens de forrageiras tropicais e sua influência no desempenho de cordeiros da raça Santa Inês, manejados em sistema de confinamento. Foram utilizados cordeiros da raça Santa Inês, não castrados, distribuídos aleatoriamente em seus respectivos tratamentos, os quais foram: silagem de milho (SM); silagem de Capim-elefante com 15% de fubá de milho (SC); silagem de parte aérea de batata doce com 15% de fubá de milho (SPAB). Dispostos em delineamento em bloco casualizado com cinco repetições. As análises de matéria seca, nitrogênio amoniacal e pH não apresentaram diferenças estatísticas entre os tratamentos, porém para as demais análises de PB, CZ, CNF, FDN, FDA, entre outras, houve diferença (P<0,05) entre os tratamentos. Resultados esses que não modificam a qualidade das silagens, apenas, apresentando diferenças diante das suas características particulares. Observou-se também que os animais alimentados com silagem de milho, silagem da parte aérea da batata doce e a silagem com capim elefante apresentaram igualdade quanto as variáveis de desempenho, como: ganho de peso total, ganho médio diário, conversão alimentar, consumo de matéria seca e de fibras em detergente neutro (kg/dia e g/kg0,75), entretanto as únicas diferenças observadas foram relacionadas ao consumo de matéria seca em % PV que foram superiores no tratamento com a silagem de batata doce, não apresentando diferença na silagem de milho e na silagem de capim elefante. O consumo de fibras em detergente neutro (%PV) apresentou diferença entre as silagens de milho e da parte aérea da batata doce, no entanto, a silagem de capim elefante apresentou igualdade para ambos tratamentos. Permitindo concluir que as silagens de capim elefante, parte aérea da batata doce e de milho apresentaram bons resultados nos seus respectivos teores bromatologico, podendo ser utilizadas sem na alimentação de cordeiros da raça Santa Inês.
The present study was performed to evaluate the quality of silages of tropical forages and its influence on the performance of lambs Santa Inês, handled in feedlot. Were used lambs Santa Inês, not castrated, randomly distributed in their respective treatments, which were corn silage (SM); Elephant grass silage with 15% of corn (SC); silage shoots sweet potato with 15% of corn (SPAB). Arranged in a randomized block design with five replication. Analyses of dry matter, ammonia nitrogen and pH did not differ among treatments, but for the remaining analyzes of CP, CZ, NFC, NDF, ADF, among others, significant differences (P <0.05) between treatments. Results that do not change the quality of the silage, only with differences on their particular characteristics. It was also observed that animals fed corn silage, silage of shoots and sweet potato with elephant grass silage showed equal as the performance variables, such as total weight gain, average daily gain, feed conversion, dry matter intake and neutral detergent fiber (kg /day and PV0,75). However the only differences were related to the consumption of dry matter in % BW which were higher in the treatment with the sweet potato silage, no difference in corn silage and elephant grass silage.The use of neutral detergent fiber (% PV) showed differences between corn silage and shoots of sweet potatoes, however, the elephant grass silage showed equal for both treatments. Allowing us to conclude that the silage shoots sweet potato, elephant grass and corn showed good results in their respective bromatological levels and can be used without impairing the performance of Santa Inês lambs.

Thesis (M. Tech.) -- Central University of Technology, Free State, 2010
This study evaluated the effects of two bacterial inoculants on the fermentation quality and aerobic stability of ensiled potato hash (PH) and on digestibility, growth performance and carcass characteristics of growing pigs fed the ensiled PH. In the first experiment, 700 grams of PH, was mixed with 300g wheat bran (as is basis) and ensiled in 1.5 litre anaerobic jars. The mixture had a dry matter (DM) of 41.3 g/kg, 78.05 g/kg DM of water-soluble carbohydrates (WSC) and a pH of 6.87 at day 0 and was treated with Bonsilage forte, BF, a heterofermentative LAB, Lalsil Fresh lactobacillus bachneri, LFLB, a homofermentative LAB or without LAB inoculant (control). Triplicate samples per treatment were collected on days 0, 3, 10, 21 and 45 post-ensiling and analysed for DM, WSC, pH, lactic acid (LA), acetic acid (AA), butyric acid (BA), propionic acid (PA) and ammonia-N. On day 45, the silage was subjected to aerobic exposure for 5 days and CO2 production was measured. In the second and third experiments, potato hash-wheat bran mixtures of 7:3 ratio were produced and ensiled in 210 litre drums that were kept at a 250C environment. The second experiment involved an apparent nutrients digestibility study using 30 female (Large White x Landrace crossbred) pigs (30 2 kg live weight), which were selected and housed individually. A cross-over design was applied with two periods and 30 animals fed 10 diets. Three pigs were given one diet per period. The diets were: commercial feed (control); 20, 40, and 60% dietary inclusion of potato hash silage (untreated potato hash silage, UPHS; Lalsil Fresh treated potato hash silage, LFLBPHS, and Bonsilage forte treated potato hash silage, BFPHS). Each experimental period lasted for eleven days with seven days being for adaptation to each diet and four days for collection of faeces before crossing over to the next treatment. Pigs were fed twice per day at 8:00 and 15:00, with the daily allowance equally divided between the two meals. Faecal samples were weighed and 10% of the total collection was taken and kept in a freezer at -180C. Prior to chemical analysis, individual samples of faeces were thawed and pooled for pigs within periods. Water was made available at all times through drinking nipples. The third experiment was a pig growth study using sixty-four crossbred pigs (Large White x Landrace) consisting of 32 males and 32 females (30.4±2.3kg live weight). The pigs were randomly allocated to four diets in a 4 x 2 (treatment x sex) factorial experiment in a completely randomised design. The diets contained up to 40% potato hash silage (PHS) and were: control (commercial diet - no silage), UPHS, BFPHS and LFLBPHS. Each experimental unit consisted of two pigs and each treatment was replicated 8 times. Pigs were fed on one of the four diets until they reached a slaughtering weight of 60 kg. Warm carcass weights were determined immediately after slaughter. After an overnight chill storage at 4.30C, cold carcass weights were determined. Carcass length was taken on hanging carcasses by measuring from the pelvic bone to the first thoracic vertebra, using a measuring tape. Backfat thickness was also taken on cold carcass at P2 (45 mm from midsection) between the 3rd and 4th rib on the left side of the pigs. Drip loss was also calculated for hanging carcasses by determining the weight loss after the overnight chill. Results from experiment 1 showed that both inoculants (LFLB and BF) reduced (P<0.05) the silage pH while increasing the LA content of silage compared to the control. The concentrations of propionic acid, butyric acid and ammonia-N were not affected by inoculation. When exposed to air, BF and LFLB reduced (P<0.05) CO2 production compared to the control. Results of the second experiment showed that daily intakes of organic matter (OM), crude protein (CP), ether extract (EE), acid detergent fibre (ADF), neutral detergent fibre(NDF), and gross energy (GE) were different (P<0.05) between diets. There were no differences (P<0.05) in digestibility of DM, EE, and DE among the treatments. However, diets containing 60% PHS had lower (P<0.05) NDF and ADF digestibility compared to diets containing less PHS. Furthermore, pigs on the control diet had higher (P<0.05) final body weight, average daily gain (ADG) and better feed conversion ratio (FCR) compared to those fed on other diets. Results of the third experiment showed that, pigs that were fed the control diet had higher (P<0.05) slaughter weight than pigs that were fed on diets containing PHS. There were no differences (P>0.05) on warm and carcass weight between diets containing PHS. Control had higher (P<0.05) dressing percentage than the other treatments. Drip loss percentage, backfat thickness, gastrointestinal tract (GIT), lungs and heart did not differ (P<0.05) between treatments. The effects of gender was not significant within treatments on slaughter weight, warm and cold carcass weights, dressing percentage, carcass length, backfat thickness, drip loss, GIT, lungs and heart. There were no gender by diet interactions (P>0.05) on warm carcass weights, cold carcass weights, drip loss percentage, carcass length, backfat, intergastral, lungs and heart. However, gender by diet interaction (P<0.05) occured on slaughter weight and dressing percentage. It was concluded that, inoculation improved both the fermentation and aerobic stability of PHS. Furthermore, there was no advantage in using LAB inoculants in ensiling potato hash on the growth performance or meat characteristics of growing pigs. However, further work is needed to evaluate the effects of higher dietary inclusion levels (> 60 %) of PHS on pig growth and reproductive performance.

CAPES; Fundação Araucária
Distribuída e cultivada em vários países, a batata-doce (Ipomoea batatas L. Lam.) é um alimento de suma importância na dieta diária da população, principalmente no continente asiático, o qual detém a maior parcela de sua produção. Essa raiz tuberosa é rica em nutrientes e fonte de energia. Além disso, algumas cultivares possuem em sua composição compostos bioativos como antocianinas, carotenoides e polifenóis, os quais apresentam atividade antioxidante e podem contribuir beneficamente para a manutenção do organismo humano. Nesse sentido, o presente trabalho objetivou a análise biométrica, a caracterização físico-química, a quantificação do total de compostos bioativos, o potencial antioxidante e o uso da tecnologia de imagem digital para estabelecer um comparativo entre o conteúdo de cor e as características físico-químicas, de novas cultivares de batatas-doces. Foram obtidas junto a Epagri-EEI/SC, amostras das raízes tuberosas das cultivares de batatas-doces denominadas SCS370 Luiza, SCS371 Katiy, SCS372 Marina, Beauregard, Uruguaia e Americana, sendo que cada variedade foi avaliada na condição in natura e liofilizada (lote um (LT1) e lote dois (LT2), respectivamente). Realizaram-se as medidas em triplicata dos parâmetros de atividade de água, acidez titulável, umidade, cinzas, proteínas, lipídeos, teor de vitamina C, açúcares totais e redutores, conteúdo total de fenólicos, flavonoides, antocianinas e carotenoides, o potencial antioxidante (ABTS+ e FRAP), cor instrumental nos espaço de cor CIE L*a*b*, CIE L*C*h° e XYZ, e imagens digitais, as quais foram obtidas por câmara digital e processadas em software desenvolvido exclusivamente para o estudo das imagens digitais de batatas-doces. O teor de minerais Cu (Cobre), Fe (Ferro), Zn (Zinco), Mn (Manganês), Na (Sódio), K (Potássio), Ca (Cálcio), Mg (Magnésio), P (Fósforo), Co (Cobalto), Cd (Cádmio), Cr (Cromo), Pb (Chumbo) resultou de uma única determinação. Outras características foram avaliadas em função de: Espectroscopia na Região de Absorção no Infravermelho, Difratometria de Raios-X, Análise por Termogravimetria e Microscopia de Varredura Eletrônica. As características resultantes para as diferentes coordenadas de cor (L*, a*, b*; C*, h°, X, Y, Z) das batatas-doces, demonstraram ser influenciadas pelas propriedades intrínsecas de cada cultivar, porém os resultados médios de cor estabeleceram uniformidades para as amostras entre seus lotes. O comparativo entre as coordenadas de cor instrumental e a análise dos diferentes canais de cor das imagens digitais (RGB, XYZ, LUV, HSV) indicaram ser possível estabelecer uma correlação entre as cultivares liofilizadas e suas imagens digitais. O teor de umidade para todas as cultivares foi característico para batatas-doces, sendo o maior valor para a cultivar (cv.) Uruguaia LT2 (83,93±0,04 %) in natura e cv. Americana LT2 (3,27±0,15 %) na condição liofilizada. A cv. SCS370 Luiza LT2 nas amostras in natura (0,94±00), exibiu o maior valor para atividade de água (Aw) sendo que todas as amostras liofilizadas apresentaram valor foi inferior a 0,15. Os valores de acidez titulável variaram para as amostras in natura de 2,77±0,08 % (cv. Beauregard LT1) a 1,51±0,07 % (cv. SCS371 Katiy LT2), e para as amostras liofilizadas de 1,86±0,09 % (cv. Americana LT2) a 0,52±0,07 % (cv. SCS371 Katiy LT1). Para o conteúdo de 9 cinzas, houve variação para as amostras in natura de 1,19±0,04 % (cv. SCS370 Luiza LT1) a 0,04%±0,00 % (cv. SCS372 Marina LT2), sendo que para as amostras liofilizadas o teor de cinzas foi superior. O conteúdo de proteínas variou entre 2,80±0,18 % (cv. Americana LT2) a 0,49±0,21 % (cv. SCS371 Katiy LT1) para as amostras in natura, e 8,20±0,09 % (cv. Americana LT2) e 3,14±0,57 % (cv. SCS370 Luiza LT1) para as amostras liofilizadas. As amostras de batatas-doces exibiram baixos valores para lipídios totais e não diferiram estatísticamente entre as cultivares. Os açúcares totais variaram entre 32,85±0,07 % (cv. SCS372 Marina LT2) e 16,99±0,044 % (cv. SCS371 Katiy LT1). Já para vitamina C, o maior conteúdo foi observado para cv. SCS370 Luiza LT2 (57,17±4,32 %) sendo o menor para cv. SCS372 Marina LT1 (17,00±1,00 %) para as amostras in natura, e entre as amostras liofilizadas o maior valor foi novamente observado para cv. SCS370 Luiza LT2 (69,78±2,20 %). Todas as cultivares de batatas-doces apresentaram conteúdo satisfatório para os minerais avaliados, com destaque para o teor de macrominerais das cv. Beauregard LT1 e SCS370 Luiza LT1. A avaliação do conteúdo total de bioativos indicou alta variabilidade entre as cultivares. O maior valor para fenólicos totais foi observado para a cv. SCS370 Luiza LT2 (3311,10±57,17 mg EAG.100g-1), e o menor valor para cv. Americana LT2 (102,62±1,22 mg EAG.100g-1), sendo estas as mesmas amostras a apresentarem o maior (148,45±1,31 mgCE.100g-1, cv. SCS370 Luiza LT2) e o menor (2,18±0,10 mgCE.100g-1, cv. Americana) conteúdo de flavonoides totais. Já para antocianinas totais, o maior valor foi observado novamente para a cv. SCS370 Luiza LT2 (155,30±6,48 mg.100g-1) e o menor valor para cv. SCS372 Marina LT2 (1,28±1,24 mg.100g-1). Os resultados para carotenoides totais variaram entre 34,04±0,66 mg.100g-1 (cv. Beauregard LT1) e 0,63±0,06 mg.100g-1 (cv.SCS371 Katiy LT2). A atividade antioxidante das amostras de batatas-doces foi satisfatória, sendo que os resultados pela metodologia de ABTS+ variaram entre 466,85±1,96 mM Trolox.100g-1 (cv. SCS370 Luiza LT2) e 128,26±4,40 mM Trolox.100g-1 (cv. SCS372 Marina LT1). Pela metodologia FRAP, a maior atividade antioxidante foi novamente observada para cv. SCS370 Luiza LT2 (734,19±63,09 mM FeSO4.100g-1), sendo a menor atividade antioxidante da cv. Beauregard LT1 (18,42±1,28 mM FeSO4.100g-1). A análise de difração de Raios X possibilitou uma tentativa de atribuição de cristalinidade das amostras liofilizadas de batata-doce, sendo classificadas como Tipo A e Tipo B. A análise de espectroscopia de absorção por infravermelho (FTIR) revelou semelhanças de grupos funcionais quando comparamos as diferentes cultivares. A análise termogravimétrica indicou os limites da resistência térmica das amostras. A microscopia eletrônica de varredura ilustrou as estruturas lamelares, os bloquetes, e a geometria dos grânulos presentes nas amostras de batatas-doces. Em função dos resultados encontrados, pode-se afirmar que as novas cultivares de batatas-doces apresentam valor econômico e nutricional agregado, tornando-se uma alternativa de cultivo para os pequenos agricultores, aumentando assim sua disponibilidade no comércio varejista, bem como sua utilização como matéria-prima industrial.
Sweet potato (Ipomoea batatas L. Lam.) is largely cultivated and greatly consumed as part of the regular diet, mainly in Asian continent, that is it’s the major producer. This tuber crop is rich in nutrient and energy source. Thus, some cultivars have bioactive compounds such as anthocyanins, carotenoids and polyphenols, which have antioxidant activity and can be beneficial to the body maintenance. In this sense, the objective of this work is to analyze the biometric, physical chemistry, quantification of bioactive compounds, antioxidant activity, and analyze digital image analysis of new sweet potato cultivars to do a comparative with their colour and physical chemistry composition. We received from Epagri-EEI/SC samples of sweet potato tuber roots named SCS370 Luiza, SCS371 Katiy, SCS372 Marina, Beauregard, Uruguaia and Americana being that cultivars analyzed in natura and lyophilized condition from batch one (LT1) and batch two (LT2). All analyses were performed in triplicate to water activity, titratable acidity, humidity, ashes, protein, lipids, vitamin C, total and reducers carbohydrates, total phenolic, flavonoids, anthocyanins and carotenoids, antioxidant activity (ABTS+ and FRAP), colour by coordinates CIE L*a*b*, CIE L*C*h° and XYZ, and digital images that was obtained by digital camera and processed with exclusive developed software to analyze that images. Mineral composition evaluation of Cu (Copper), Fe (Iron), Zn (Zinc), Mn (Manganese), Na (Sodium), K (Potassium), Ca (Calcium), Mg (Magnesium), P (Phosphorus), Co (Cobalt), Cd (Cadmium), Cr (Cromium), Pb (Lead) was performed by once. Another set of characteristics was evaluated by Infra-Red Spectroscopy with Fourier Transformed, X Rays Diffractometry, Thermogravimetric Analysis and Scanning Electron Microscopy. The sweet potato colour results from different coordinates (L*, a*, b*; C*, h°, X, Y, Z) showed be influenced by cultivar intrinsic properties but the standard results establish sample uniformities to different batches. Comparison between colour coordinates and digital images colour channels (RGB, XYZ, LUV, HSV, HLS) showed to be possible to establish a correlation between the lyophilized samples and they digital images. Sweet potatoes humidity quantification showed high value to cultivar (cv.) Uruguaia LT2 (83.93±0.04 %) in natura and lyophilized cv. Americana LT2 (3.27±0.15 %). The cv. SCS370 Luiza LT2 in natura (0.94±00) showed the highest value to water activity, and all lyophilized samples showed low value as 0.15. Titratable acidity values ranges for in natura samples by 2.77±0.08 % (cv. Beauregard LT1) to 1.51±0.07 % (cv. SCS371 Katiy LT2), and 1.86±0.09 % (cv. Americana LT2) to 0.52±0.07 % (cv. SCS371 Katiy LT1) for lyophilized samples. Ashes content showed variation for in natura samples by 1.19±0.04 % (cv. SCS370 Luiza LT1) to 0.04%±0.00 % (cv. SCS372 Marina LT2), but lyophilized samples showed highest ashes values then in natura. Protein content ranges by 2.80±0.18 % (cv. Americana LT2) to 0.49±0.21 % (cv. SCS371 Katiy LT1) for in natura samples, and 8.20±0.09 % (cv. Americana LT2) to 3.14±0.57 % (cv. SCS370 Luiza LT1) for lyophilized samples. Sweet potatoes cultivars exhibited low values to total lipids and their values do not shows statistical variation. Total carbohydrates composition ranges between 32.85±0.07 % (cv. SCS372 Marina LT2) 11 and 16.99±0.044 % (cv. SCS371 Katiy LT1). The vitamin C content was highest to cv. SCS370 Luiza LT2 (57.17±4.32 %) and lowest to cv. SCS372 Marina LT1 (17.00±1.00 %) for in natura samples, but cv. SCS370 Luiza LT2 (69.78±2.20 %) shows the highest value for lyophilized samples. All sweet potatoes cultivars showed great content for the evaluated minerals with emphasis for the macrominerals content of cv. Beauregard LT1 and SCS370 Luiza LT1. The bioactive compound shows high variation between sweet potatoes cultivars. The phenolic highest values was observed to cv. SCS370 Luiza LT2 (3311.10±57.17 mg GAE.100g-1), and the lowest value was cv. Americana LT2 (102.62±1.22 mg GAE.100g-1), and those same samples showed the highest (148.45±1.31 mg CE.100g-1, cv. SCS370 Luiza LT2) and lowest (2.18±0.10 mgCE.100g-1, cv. Americana) total flavonoid composition. The total anthocyanins composition showed again highest value to cv. SCS370 Luiza LT2 (155.30±6.48 mg.100g-1) and lowest value to cv. SCS372 Marina LT2 (1.28±1.24 mg.100g-1). Total carotenoids result ranges by 34.04±0.66 mg.100g-1 (cv. Beauregard LT1) to 0.63±0.06 mg.100g-1 (cv.SCS371 Katiy LT2). The sweet potatoes antioxidant activity was great and the results by ABTS+ test ranges by 466.85±1.96 mM Trolox.100g-1 (cv. SCS370 Luiza LT2) to 128.26±4.40 mM Trolox.100g-1 (cv. SCS372 Marina LT1). By the FRAP teste, the highest antioxidant activity was again observed to cv. SCS370 Luiza LT2 (734.19±63.09 mM FeSO4.100g-1), and the lowest antioxidant activity was cv. Beauregard LT1 (18.42±1.28 mM FeSO4.100g-1). The X Rays diffractometry analysis enabled an attempt to assign the lyophilized sampled crystallinity that was considered by Type A and Type B. The infrared spectroscopy analyses showed similarity to the functional groups when compared the sweet potato samples among different batches. Thermogravimetric analysis indicates the sample thermal resistance. The electron microscopy scanning shows the lamella structure, blocks, and granular geometrical structure in the samples. Having in mind the results obtained, it is possible to support the new cultivars of sweet potatoes have an economic and nutritional added value, as they become an alternative of cultivation for small farmers, increasing their availability in the retail trade, as well as their use as industrial feedstock.

Forage of beta-carotene-fortified orange-fleshed sweet potato is essential for alleviation cattle malnutrition. The study aims were to determine effects of supplementing sweet potato (SP) roots and sun dried forage on degradation of dietary legumes, intake and milk yield in dairy cattle. Mature SP roots were oven dried and forage vines and leaves (V&L) sun dried. Lactating dairy were supplied meals with total mixed ration (TMR) constituting varying levels of sweet potato forage and concentrate. The SP flour was rapidly and completely degraded In Sacco while degradability of V&L was comparable to that of Lucerne hay. Rumen degradation of Lucerne was reduced when the legume was incubated proximal to SP. Substitution of TMR with fresh SP forage and flour meal increased degradability of diets. Glucose post-feeding was increased (P<0.05) by SP roots but no change in milk yield. Orange-fleshed SP forage is recommended for improving energy supply in lactating cow diets
Agriculture and  Animal Health
M. Sc. (Agriculture)

Research Doctorate - Doctor of Philosophy (PhD)
Centring Indigenous Knowings when conducting research is more than placing the word 'Indigenous' in front of the word 'research'. Indigenous Knowings represented and embodied here as a Waterlily is fundamentally different to Western Knowledges (represented by a Brick Wall). This thesis explores some epistemological consequences of Knowledge production in Australia; it is a story I know told by many voices, many difference stories - stories that do not contradict each other, they simply co-exist. This thesis documents my struggles and those of other Indigenous researchers operating and existing within a contested zone. A zone of colliding trajectories between The Academy (the Brick Wall) and Indigenous Knowings (Waterlily). Adventuring and exploring within this zone the thesis voices challenges, options and most importantly choices for us as Indigenous researchers; not Indigenous peoples who happen to be doing research about Aboriginal issues, Aboriginal peoples. A webpages designed to accompany this thesis creates and gives dimension and depth to the linear, Western framework that is a thesis. I have journeyed with my colleagues in Desert and Coast yarning with them, being told and shown experiences that form the essence of this thesis. An essence that unequivocally centres and privileges Indigenous voices, Indigenous Knowings. This thesis contributes to a new and vibrant theorising space; one that Denzin and Lincoln identify as the Eighth Moment (Denzin & Lincoln, 2005, p.20). It is an act of intellectual self-determination (Battiste M., 2002, p. 4); an effort to develop new analyses and methodologies to decolonise myself, my communities and the institutions that impact on our daily lives. I reclaim and re-position Indigenous Knowings so that we can all find a path ahead making sustainable and good choices (Henderson, 2000, p. 274).

Extensive use of fossil fuels over the years has resulted in increased petrol and electricity prices as well as negative impacts on the environment resulting from increased Green House Gas (GHG) emissions. There is therefore a need for a renewable and more environmental friendly source of energy. The aim of this study was to produce an alternative fuel source in a form of biofuels from sweet potato tuber using a laboratory-scale Fluidized Bed Bio-Reactor (FBBR). Sweet potato was a substrate of choice because of its high carbohydrate content. Although sweet potato is a food source, there is a huge surplus annually which is regarded as waste. Bacteria isolated from sweet potato tuber were identified based on their 16S rRNA sequence using colony PCR followed by sequencing. Strains identified belonged to species: Klebsiella, Enterobacter, Rhodobacter, Bacillus, Citrobacter, Alcaligenes and Bordetella. Industrial applications of each bacterial isolate were predicted from known bacterial species. Batch fermentation was operated using M9 minimal growth medium and GP medium and a consortium of the identified species. In these experiments, pH was measured but not controlled. Using M9 minimal growth medium, acetic acid (48.6 g/l), ethanol (29 g/l), propionic acid (29 g/l), butyric acid (22.9 g/l), methane (21.1 g/l), hydrogen (3.2 g/l) and carbon dioxide (6.2 g/l) were produced; however, lower concentrations were produced in GP medium (acetic acid, 13.1 g/l; ethanol, 7.3 g/l; propionic acid, 16.7 g/l, methane, 0.2 g/l; hydrogen, 1.7 g/l and carbon dioxide, 0.6 g/l) except for butyric acid, 23.6 g/l. Under fluctuating pH conditions, higher concentrations were obtained at a pH value of 6.0. Based on results, it appeared that M9 medium and pH 6.0 were preferred. However, liquid and gas products obtained at controlled pH 6.0 were lower than those obtained under uncontrolled pH conditions. This resulted in using M9 medium under uncontrolled pH conditions in a continuous FBBR. Three Hydraulic Retention Times (HRTs) of 6 hours, 3 days and 12 days were investigated. FBBR was operated at each HRT over 42 days with a 14 day interval. HRT of 6 hours resulted in the highest productivity. Maximum concentrations of acetic acid (18.5 g/l), ethanol (5.2 g/l), propionic acid (16.9 g/l), butyric acid (16.9 g/l), hydrogen (16.3 g/l) and carbon dioxide (5.3 g/l) were obtained by day 42. Bacterial growth dynamics were monitored by plate counts while cell attachment on granular activated charcoal (GAC) was studied using scanning electron microscope (SEM). SEM micrographs showed attachment of bacterial cells as well as extracellular polymeric substance (EPS) indicating that mixed cultures used in this study were able to form biofilms.

碩士
中臺科技大學
食品科技研究所
100
The Sweet potato (Ipomoea batatas (L.)), originate from American tropics, belongs to the family of Convolvulaceae. Sweet potato is the sixth most important food crop in the world, and it contains a great amount of nutrients and is rich in antioxidant activity. This study is to evaluate the antioxidant activity of ethanolic and hot-water extracts from seven cultivars of sweet potatoes namely, Simon 1 (S1), Tainong No. 57 (TN57), Tainong No. 64 (TN64), Tainong No. 66 (TN66), Tainung No. 68 (TN68), Tainong No. 71 (TN71) and Tainong No. 73 (TN73). According to the analyzed of the proximate composition in the various strains of sweet potatoes, the moisture contents of them are the range of 14.46~6.29%. The carbohydrate contents are the range of 87.97~94.30%. The highest values of the components in TN66, and their reducing sugar, crude ash and crude fiber, contents are 85.06, 3.95 and 1.88%, respectively. The crude fat contents of TN64 is the highest value (1.32%), and crude protein contents of S1 is the highest value (6.00%). The ethanolic extraction yields of the seven cultivars of sweet potatoes are higher than hot-water extraction yields. Antioxidant properties of seven cultivars of sweet potatoes are studied in the form of ethanolic and hot-water extracts. Using the conjugated diene method, the ethanolic and hot-water extracts from seven sweet potatoes at 20 mg/mL are in the range of 83.61~96.08% and 30.66~90.87%, respectively. In the reducing power of both extracts from S1 and TN71 are more than 1.00 at 20 mg/mL. In scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, at 10 mg/mL, the ethanolic extracts is higher than hot-water extracts. In the chelating ferrous abilities, the ethanolic and hot-water extracts of sweet potato slowly increased. At 20 mg/mL the ethanolic extracts of the chelating ferrous abilities for S1 and TN73 are 57.57, 55.62 and 99.81%, and the hot-water extracts for TN64, TN66 and TN73 are more than 50%. Total phenols are the major naturally occurring antioxidant component found in all samples. The β-carotene and α-tocopherol contents of ethanolic extract are higher than those of hot water extracted. In conclusion, these sweet potatoes contain abundant high carbohydrate. The antioxidant properties of sweet potatoes in the antioxidant activity and scavenging DPPH abilities from ethanolic extracted are better than those from hot-water extracted. However, the chelating effect on ferrous ions and reducing powers of hot-water extracted are better than ethanolic extracted. In antioxidant components, total phenols content is the major naturally occurring antioxidant components found in the sweet potatoes, and that of the ethanolic extracted is more than hot-water extracted. Therefore, sweet potatoes have great antioxidant properties due to higher total phenol compounds.

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important food crop in East Africa including Kenya. The crop incurs high yield losses in production due to biotic (insect pests and diseases) and abiotic (drought, and heat) constraints. Among abiotic constraints, drought is the most important. Prolonged periods of drought in arid and semi-arid areas of Kenya have led to reduced quantity and quality of sweetpotato storage roots and in severe cases caused total crop failure. The objectives of this study were to: 1) determine sweetpotato production system constraints and farmers’ coping strategies; 2) evaluate sweetpotato clones for yield performance and drought tolerance; 3) analyse genotype x environment interaction and stability for storage root yield of selected clones, 4) determine mechanisms of drought tolerance in sweetpotato, and 5) determine combining ability and heterosis for yield and drought tolerance traits under managed drought stress conditions. To determine the production constraints and farmers’ coping strategies, a survey was conducted in central, eastern and western Kenya. Out of 345 farmers interviewed, 60% were women, and 40% men. Farm sizes ranged from 0.4-0.8 ha, with 90% of sweetpotato cultivated on 0.2 ha or less. The main sweetpotato varieties were Vitaa, Kabonde and Bungoma and the majority of farmer’s used their own conserved planting material which was conserved by leaving them in the field after harvest. About 35% of the farmers identified weevils as the major pest, and sweetpotato virus disease (SPVD) as the major disease, while 28% of the farmers identified drought as a major constraint. The farmers used clean seed, high yielding varieties, high planting density, and manure application as the main strategies to cope with sweetpotato production constraints. Eighty four sweetpotato clones were evaluated under managed drought stress environments at KARI-Kiboko and KARI-Thika. Drought reduced the fresh weight of storage roots (FSR) (72.5%), fresh biomass weight (FB) (74.0%), marketable fresh storage root (MFSR) (80.7%), number of storage roots (NSR) (24.5%), days to permanent wilting point (DPWP) (0.3%), but seemed to increase percent root dry matter (% RDM) (-4.7%), harvest index (HI) (-2.6%), and chlorophyll content (CC) (-2.7%). Across the environments, genotypes 194555.7 (1.06), 421066 (1.05), Chingovu (0.94), 420014 (0.91), Excel (0.9), 199062.1 (0.87) and Unawazambane06-01 (0.81) gave higher FSR yields (kg plant-1) than the local checks. Genotypes Nyarmalo and Polista were among the lowest yielding in the irrigated and non-irrigated conditions. Clones W119, 441725, and Xiadla-xa-kau were the highest yielding under the drought stress conditions. The performance of 24 improved clones was evaluated in replicated trials at KARI-Thika and KARI-Kiboko using 24 sweetpotato clones grown under managed drought stress conditions for two seasons. AMMI, GGE biplots and regression analyses were conducted to determine stability of the clones. Mean FSR was significantly different (P < 0.001) in the two research sites with the environment contributing to 92.7% of the total variation, genotype 1.8%, and interactions 0.4%. AMMI and GGE biplots, and regression indicated the most stable clones to be 441725, Unawazambane06-01 and 189150.1, while Xiadla-xa-kau was the least stable. To gather more information on drought tolerance mechanisms expressed in the sweetpotato genotypes, an experiment was conducted in the greenhouse using clones expressing different levels of drought tolerance in the field. The results showed more under-developed roots (pencil roots) in the drought stressed regimes than in the irrigated regimes and in the drought susceptible genotypes. Drought tolerant genotypes produced more FSR and NSR. The number of vine branches (NVB), vine tip pubescence (VTP) and mature leaf pubescence (MLP) increased with reduction of drought stress however, drought tolerant clones had reduced NVB. Drought stressed clones had shorter basal vine length (BVL), reduced CC, and reduced leaf growth (LG). Drought stress reduced growth of vines in terms of internodes length, internodes diameter, vine length, petioles length, and leaf CC. Overall, for the first time, the study demonstrated that drought stress in the first three months after planting, leads to the proliferation of non-edible pencil roots, which do not become edible storage roots even when drought stress is removed. Therefore, water is critical during this period for improved sweetpotato storage root yield, probably as a drought tolerant mechanism. Combining ability for yield and drought tolerance of 15 F1 sweetpotato families generated through a half diallel mating of six parents was evaluated at KARI-Kiboko in 2012. Significant (P≤0.05) general combining ability (GCA) and specific combining ability (SCA) effects were recorded for root yield in both drought stress and no stress conditions, indicating that both additive and dominance gene effects were important in the inheritance of resistance to drought stress. Progenies from families G2, G5, G7, G8, G10, G12 and G15 had good SCA for fresh storage root yield, total biomass, number of days to permanent wilting point (DPWP), harvest index, and drought stress index (DSI). Progeny 8 from family G4, 5 and 8 from G15, had the highest mid and best parent heterotic effect (117-270%) for fresh storage root yield in both drought stress and no stress conditions. Progeny 6, and 7 from family G10, had the highest mid and best parent heterotic effect (165-234%) for fresh total biomass yield under no drought stress conditions. In conclusion, the progenies from families G2, G5, G7, G8, G10, G12 and G15 that had high yield and biomass specific combining ability under drought and no drought stress indicated that they could be having drought tolerant genes, and therefore could be incorporated into advanced drought screening trials with the aim of releasing the best performing drought tolerant varieties. Secondly, the findings in this study lay a foundation for sweetpotato breeding programmes on drought tolerance. Thirdly, for the first time, this study uniquely combines yield performance, combining ability estimates, days to permanent wilting point and heterosis under contrasting moisture regimes to unmask the gene action of drought tolerance in sweetpotato, a milestone in science.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

碩士
明新科技大學
化學工程與材料科技系碩士在職專班
104
ECO-enzyme is a good countermeasure for solving environmental problems of this century, not only that the materials are easily obtained, it also solves the Government and family’s problems of wet garbage, to achieve waste reduction, and turns junk into gold. Dr. Le Sukun (Dr. Rosukon) from Thailand has been researching about enzymes for more than 30 years, and has successfully developed Eco-enzymes (also known as Junk-Garbage Enzyme). The Eco-enzyme is the brown or yellowish liquid with the pungent odor of vinegar, produced from the fermentation of the mixture composed by sugar. Eco-enzyme is simple and easy to make, and there are endless number of usages, and can be a great help in agriculture, aquaculture and even at home. This study uses two types of commonly seen, cheap and readily available sweet potatoes from the market; 57th, yellow, yellowish flesh and tainong 66 red red meat. Using 3 methods: baked, steamed and washed with 3 groups: five days of constant temperature control fermentation group, unfermented group, and the fermentation of different carbon source concentrations enzyme solution in a group which has been soaked for three months. The lowest total phenol content comes from the unfermented group, the temperature controlled fermentation Group increased by 9.2%~46%, and obtained another 4.06-4.93 times of total phenols increased by turning it into enzyme liquid. Highest content of flavonoids was found in the unfermented group. After five days of constant temperature control, the amount has declined to 26%-57%, and after turning into eco-enzyme, will have a drop in ratio of 18% - 25%. Detection of antioxidant capacity in five ways: 1.Clearation of the DPPH radical scavenging abilities: the red meat sweet potato soaked in 5% diluted enzyme for a year will receive 64.61% of clearance, with 10% dilution will achieve a 86.66% of clearance. The unfermented group and the constant temperature control group processed an average above 95% of clearance. Unfermented group and constant temperature control fermentation group processed over 95%, whereas there are only 54% of clearance with the raw group. After comparison, discovered that cooked sweet potatoes has a higher DPPH radical scavenging abilities than the raw. 2.Restoring force: the red meat sweet potato soaked in 5% diluted enzyme for a year will obtain the absorbance of 1.89. The second highest is the yellow meat sweet potatoes with 5% liquid immersion for 6 months, obtained the absorbance of 1.45. The research shows that the longer the enzyme’s soaked, the better the restoring power. 3.Ferrous ion chelating ability: the liquid enzyme groups all demonstrated negative values, processed fermentation and fermentation temperature control groups demonstrated an average of 81.8-93.2%, with unfermented group showing better results than the fermented temperature control group. 4.Inhibition of linoleic acid peroxidation ability: liquid enzyme group with 1% dilution demonstrated above 57% of clearance. Liquid enzyme group demonstrated higher clearance rate than the unfermented group and the fermented temperature control group. 5.The superoxide anion: unfermented group and fermented temperature control group both received an negative average value. Liquid enzyme with below 10% dilution will receive the clearance of EC50. With assessing the whitening ability - the tyramine acid enzyme inhibition, the best result comes from red meat sweet potatoes unfermented group of 152.29% extraction. Followed by the steamed fermented red meat sweet potatoes with 112.64%, third the yellow meat sweet potatoes steamed fermented of 112.64%. The study can be used in the future for cosmetic whitening products and on the prevention and treatment of disease related to abnormal melanin reference. Keywords: Sweet potatoes, Garbage, Eco-enzymes, Anti-oxidation, Whitening

Starch residue samples from two Australian sweet potato varieties (Beauregard and Northern Star) and two Indonesian sweet potato varieties (Bis192 and Bis183), and commercial sample of sweet potato starch residue, were studied for their pectins. Pectins were extracted using 0.1M HCl, 0.05M NaOH, 0.1M HCl/0.75%SHMP, and 0.05M NaOH/0.75% SHMP. Hydrolysis of residual starch in the cell wall of sweet potato using heat stable α-amylase and amyloglucosidase was employed prior to pectin extraction to eliminate starch contamination. Pectins were characterised for yield, moisture, ash, galacturonic acid content (GA), degree of esterification (DE), neutral sugars content and molecular weight (MW). Selected pectins were also characterised for their dispersion and gel properties. Pectin with the highest yield was compared to commercial low methoxyl pectin (GRINSTED??YF 450) for its application in milk pudding. The pectin characteristics are dependent on variety and extraction process; however, the extraction methods were dominant. Yields were between 7 and 30 % of the cell wall. Ash varied from 2.9 to 6.8%. NaOH/SHMP extraction gave higher yields and ash contents. Moisture was between 5.5 and 6.7. GA varied from 27 to 80% with the highest found in Bis192 extracted using NaOH/SHMP. DE varied between traceable and 57%. HCl extraction gave higher DE, while NaOH/SHMP caused demethylation. Neutral sugars varied from 10 to 25% where galactose was the predominant sugar, followed by arabinose, rhamnose, glucose and xylose. Pectin MW was very heterogeneous. HCl extraction gave higher MW than the others. Dispersion of sweet potato pectins displayed shear-thinning. Consistency coefficient (K) increased, while flow behaviour index (n) decreased with increasing pectin concentration. HCl-extracted pectins formed stiff sugar-gels at concentrations higher than 2%. The optimum Ca2+ concentration for NaOH/SHMP-extracted pectin gels was 20 mg/g pectin. Pectin with the highest yield and stiffness (Norther Star extracted using NaOH containing SHMP) was used for milk pudding preparation. This pudding had comparable texture to pudding prepared from commercial low methoxyl citrus pectin (GRINSTED??YF 450). Overall, this study demonstrated that pectin from sweet potato starch residue is mainly low methoxyl pectin with possible chemical structure of rhamnogalacturonan I (RGI) that has potential for food applications.

Sweetpotato (Ipomoea batatas, L.) is one of the important sources of carbohydrates and economic income in Mozambique. As with most of the food crops in Mozambique, it is usually produced by small-scale farmers under dryland conditions. Despite the importance of the crop, the storage root yields are still low and it is difficult to keep planting material (vines) for the next planting season. One of the major challenges to production is drought stress. Drought stress affects sweetpotato by retarding aboveground growth, reducing total root yield, percentage of dry mass, and reducing the quality of the roots as a result of the increase in damage caused by the sweetpotato weevil (Cylas formicarius). The objective of this study was to identify sweetpotato genotypes tolerant to drought particularly amongst the orange fleshed types which can be used in breeding programmes to improve the drought tolerance of genotypes grown in Mozambique. To this end, 48 genotypes were evaluated in both field and greenhouse studies conducted at Umbeluzi Research Station (26º 03’ S, 32ºC 23’ E; 12 masl) located about 30 km from Maputo city. The field trial was a three replicate, α-design with split-plots. Genotypes were the wholeplot treatment factor and irrigation levels were the sub-plot treatment factor. The three irrigation levels imposed were: nonstressed plants irrigated from planting to 120 DAP; moderately stressed, plants irrigated until 60 DAP; and severely stressed, plants irrigated until 30 DAP. In the greenhouse trial the 48 genotypes were grown in wooden boxes arranged in a two replicate, randomized complete block design. The plants were exposed to water stress from 10 DAP to the end of experiment at 60 DAP. Genotypes were significantly different for all traits, namely: survival %, vine vigour, aboveground biomass, total and commercial root yield, total fresh biomass, harvest index, β-carotene content, % dry mass, dry mass yield, incidence of sweetpotato virus disease, and incidence of weevil damage. Irrigation levels were significant for the traits: survival %, vine vigour, aboveground biomass, total and commercial root yield, total fresh biomass, harvest index, β-carotene content, % dry mass, and dry mass yield. Irrigation levels were not significant for incidence of sweetpotato virus disease and incidence of weevil damage. The genotypes x irrigation levels interaction was significant for: total and commercial root yield, and incidence of weevil damage; and not significant for: survival %, vine vigour, aboveground biomass, total fresh biomass, harvest index, β-carotene content, % dry mass composition, dry mass yield and incidence of sweetpotato virus disease. The mean dry mass yields across irrigation levels of the national breeding lines and introduced genotypes were higher than the landrace genotypes. Most of the national breeding lines had higher β-carotene content than the introduced and landrace genotypes. The landrace genotypes had relatively higher % dry mass composition compared to the national breeding lines. The stress tolerance index (STI) separated the 48 sweetpotato genotypes evaluated in the field trial into three groups: drought tolerant (high STI); moderate drought tolerant (intermediate STI); and drought sensitive (low STI). Under moderate stress, yield potential (Yp) and yield in a stress environment (Ys) were highly significant, positively correlated with Mean productivity (MP), Geometric mean productivity (GMP), Stress tolerance index (STI) and Tolerance index (TOL). Under severe stress the same correlations were reported. Under moderate and severe stress, the correlation between stress tolerance index (STI) and Stress susceptibility index (SSI) was significant and negative. In the greenhouse trial, differences between genotypes in vine length increment, vine diameter increment, leaf width increment and number of nodes vine-1 were significant (P<0.05). Vine length, vine diameter, leaf width and length increments either increased or were reduced due to water stress. Less than 10% increment in vine length (between 25 and 50 DAP) was recorded in MGCl01, Atacama, Cordner, Beauregard, and CN1448-49. Higher than 40% vine length increment was recorded in Jonathan and UNK-Malawi, Naspot, MUSG0614-24, Resisto, K566632, Tainung64, Ejumula and MUSG0623-09. Vine diameter decreased in Manhissane and MUSG0616-18. No change in leaf length in Tacna and Jonathan and in leaf width in Xihetamakote and Resisto-Nairobi was recorded. The longest petiole length at 30 DAP was recorded by Tacna and the shortest by Nhacutse4. The longest internode length was recorded in 199062.1. Similar to petiole length, Nhacuste4 reported the shortest internode length. The highest number of primary vines was recorded by MUSG0608-61 and lowest by Beauregard. Of the 48 genotypes exposed to water stress, 18 survived until the end of the greenhouse experiment at 60 DAP and were therefore considered to be drought tolerant.
Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, 2011.