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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Establishing the nutritional value of field pea as affected by feed processing and pea cultivar for poultry

2013 May 1900 (has links)
The effects of feed processing, pea cultivar and their interaction on the nutritional value of field pea (Pisum sativum L.) for poultry were evaluated in regard to its apparent metabolizable energy (AMEn), apparent protein digestibility (APD), and rate and extent of starch digestion. Amino acid sparing as affected by the rate of starch digestion was studied in laying hens and broiler chickens. Also, the effects of feeding a slowly digested starch (SDS) from pea on performance and metabolism of broiler–breeder pullets were investigated. The first objective of this research was to evaluate the effects of screen–hole size, cold pelleting, and pre–pelleting conditioning temperature on nutrient digestibility of pea. There was no interaction between dietary treatments on all studied parameters. Small hammer–mill screen–hole size (3.2–mm) increased AMEn, APD, and extent of starch digestion values compared with coarse screen–hole size (6.4–mm). The AMEn and extent of protein digestion were not affected by cold pelleting, but the site of protein digestion was affected. In contrast, cold pelleting increased the rate and extent of starch digestion. Pre–pelleting conditioning temperature affected AMEn of pea in a quadratic fashion but had no positive effect on starch digestibility. The 70°C of pre–pelleting conditioning temperature maximized pea AMEn. Increasing pre–pelleting conditioning temperature decreased APD in a linear fashion. The second objective of this research was to study the effects of feed processing, pea cultivar and their interaction on AMEn, APD, and rate and extent of starch digestion. In vitro and in vivo experiments were conducted. An in vitro procedure simulating the gastric and small intestine conditions of chickens was developed to predict the rate and extent of starch digestion as affected by pea cultivar and sieve–hole size (0.5–, 1.0–, 2.0–mm). The rate and extent of starch digestion of cereal grain samples (barley, corn, and wheat) was also compared to pea starch. No interactions were found between pea cultivar and sieve–hole size on the kinetics of starch digestion. Pea cultivar affected the rate and extent of starch digestion. The small sieve–hole size in the in vitro assay resulted in a higher rate and extent of starch digestion. Pea starch was slowly digested in comparison with cereal grains. The in vivo experiment confirmed that fine grinding and pelleting improves AMEn and APD. Cultivar effects on AMEn and APD were observed, but no interaction was found between pea cultivar and feed processing. The third objective of this research was to investigate whether feeding SDS from pea would have sparing effect on amino acid utilization in chickens. In the first experiment, the effects of three levels of pea inclusion 0, 150, 300 g/kg on the response of laying hens to three levels of lysine intake (700, 780, and 860 mg per day) were evaluated using performance and production criteria. This experiment revealed that pea inclusion up to 300 g/kg in laying hen diets was well tolerated by laying hens and improved energy retention as indicated by increased body weight and egg weight. However, this experiment did not confirm the hypothesis that SDS from pea spared amino acids for laying hens. The second experiment investigated the interaction between SDS derived from pea and amino acid levels on the performance and carcass quality of broiler chickens. Six levels of pea inclusion (0, 150, 300, 450, 600, and 750 g/kg) and two levels of amino acids (100 and 85% of Ross × Ross 308 requirement) were examined in a broiler trial (0 – 35 d). The maximum level of pea inclusion recommended in diets increased with broiler age, but the effect of SDS from pea on amino acid sparing could not be confirmed. In the third experiment, the effects of feeding SDS from pea on growth performance and metabolism of broiler breeder pullets were investigated. Body weight and uniformity of pullets fed pea–based diet were similar to that of a wheat–based diet. Target body weight and uniformity of pullets were not affected by feeding a diet containing 890 g/kg of pea. Mean blood glucose levels and relative liver weight were markedly lower in broiler pullets fed pea–based diet compared with those fed a wheat–based diet. In conclusion, feed processing independently had a significant effect on the availability of pea nutrients. Pea is a good source of both energy and protein and that it can be partially or completely included to replace wheat and soybean meal in poultry diets. However, the effect of SDS on amino acid sparing could not be confirmed. Further research is needed to examine other feed processing techniques, pea cultivars, level of inclusion, and to understand other metabolism responses to feeding SDS from pea.
2

The Effects of Pressure-Assisted Thermal Processing on the Quality Attributes of Black Beans (<i>Phaseolus vulgaris L.</i>)

Somerville, Jeremy Alan January 2009 (has links)
No description available.
3

The development of Amadumbe (Colocasia esculenta (l.) schott)-soya composite biscuits with improved nutritional and sensory properties

Mokhele, Tabea Mokgalakane 06 1900 (has links)
The Amadumbe crop [Colocasia esculenta (L.) Schott] is a traditional Southern African tuber crop which is rich in starch, mucilage and micronutrients. Amadumbe tubers have limited amount of proteins and as a result, amadumbe-processed foods lack adequate protein. The purpose of this study was therefore to develop protein-rich amadumbe-soya composite biscuits, which would be acceptable to consumers. Biscuits were prepared by combining amadumbe and soya flours at ratios: 90:10, 70:30 and 50:50. Functional properties of composite flours and the physical properties of composite biscuits were determined. The proximate composition, amino acid composition and protein digestibility of composite biscuits were determined. Consumer acceptability test of biscuits was performed using nine-point hedonic scale. The results indicated that the 90% amadumbe and 10% soya composite biscuits had high significant values of moisture, ash, carbohydrates contents and energy values. The 50% amadumbe and 50% soya composite biscuits had significantly high values of fat, crude protein contents and acid detergent fibre (ADF). The protein digestibility, amino acid contents, especially the lysine contents of composite biscuits increased significantly (p ≤ 0.05) with an increase in the percentage of soya. The mineral contents of composite biscuits; Ca, Mg, P, Zn, Cu, Mn and Fe increased significantly (p ≤ 0.05) with the increase of soya in the composite biscuits. There was a significant difference in the mean taste acceptability and mean overall acceptability when the soya concentration was increased to 50%. Soya was successfully used to produce amadumbe composite biscuits with better nutritional quality with respect to protein content, amino acid profile and selected mineral contents and which were acceptable to consumers. / National Research Foundation (South Africa) / Life and Consumer Science / M.Sc. (Agriculture)
4

Efeito do consumo de farinha de linha?a (Linum usitatissimum) no crescimento de ratos Wistar e rela??o com a digestibilidade de globulinas e fatores antinutricionais prot?icos

Lopes, Katya Anaya Jacinto 28 June 2007 (has links)
Made available in DSpace on 2014-12-17T14:03:25Z (GMT). No. of bitstreams: 1 KatyaAJ.pdf: 641948 bytes, checksum: 8145771d141a135b5fa6f7f5586cd02d (MD5) Previous issue date: 2007-06-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Linseed is an important oilseed consumed raw as nutritional supplement, that although represents a rich source of nutrients, its nutritional value could be impaired due to the presence of antinutritional factors. In this study, protein fractions from raw linseed flour were extracted and isolated being obtained 12% of albumins, 82% of globulins, 5% of glutelins and 1% of prolamins. These proteins were visualized by SDS-PAGE and albumins showed low molecular mass protein bands around 21 kDa and minor bands, similar to that of trypsin inhibitor; Globulins presented protein bands with high molecular masses, which possibly are constituents of multimeric proteins, such as legumins. After determination of the centesimal composition of raw linseed, it was used as exclusive protein source for young rats to evaluate its effect on animal growth. The results showed negative effects on rat growth (weight gain 73% less than the control group) and reduction of intestinal villus (35%), that could be related with in vitro and in vivo globulin digestibility and proteinaceous antinutritional factors (mammalian digestive enzymes inhibitors and lectins) in albumin fraction. Native globulins showed, by SDS-PAGE, low susceptibility in vitro to trypsin and chymotrypsin, however presented high degradation by pancreatin. Thermal treatment of globulins for 5 and 15 minutes at 100?C improved considerably its digestibility by trypsin and pancreatin. Globulins presented 93.2% in vivo digestibility, similar to the control protein. Albumin fraction had high trypsin inhibition activity (100%) and chymotrypsin inhibition of 28.3%; haemagglutinating activity was not detected. The results of this study indicate the negative action of trypsin inhibitors on animal growth, but can not be discarded its combined action with other antinutritional factors, which could compromise the raw linseed utilization as an alternative food / A linha?a (Linum usitatissimun) ? uma importante oleaginosa consumida crua como suplemento nutricional, que apesar de representar rica fonte de nutrientes, pode ter valor nutricional reduzido devido ? presen?a de fatores antinutricionais. Neste estudo as principais fra??es prot?icas da farinha de linha?a crua foram extra?das e isoladas, sendo obtidos 12% de albuminas, 82% de globulinas, 5% de glutelinas e 1% de prolaminas; o padr?o eletrofor?tico das prote?nas mostrou que as albuminas apresentaram bandas majorit?rias de baixa massa molecular em torno de 21 kDa e menores, indicativas da presen?a de inibidores de tripsina, e nas globulinas foram observadas algumas bandas intensas que provavelmente comp?em uma prote?na multim?rica de alta massa molecular do tipo legumina. Ap?s a obten??o da composi??o centesimal da farinha crua, esta foi usada como fonte exclusiva de prote?nas para ratos rec?m-desmamados, a fim de avaliar seu efeito no crescimento dos mesmos. Os resultados de depress?o do crescimento (ganho de peso 73% inferior ao grupo padr?o) e redu??o no crescimento dos vilos intestinais (35%) levaram ? verifica??o da digestibilidade in vitro e in vivo da fra??o globulina e detec??o de fatores antinutricionais prot?icos (inibidores de enzimas digest?rias de mam?feros e lectinas) na fra??o albumina, como poss?veis fatores delet?rios ao crescimento dos ratos em estudo. As globulinas nativas apresentaram baixa susceptibilidade a digest?o in vitro por tripsina e quimotripsina, no entanto sofreram maior degrada??o pela pancreatina. O aquecimento das globulinas por 5 e 15 minutos a 100?C aumentou consideravelmente a digestibilidade pela tripsina e pancreatina. No experimento de digestibilidade in vivo, a globulina apresentou alta susceptibilidade ? degrada??o pelas enzimas digestivas (93,2%), semelhante ? prote?na padr?o. Na avalia??o da fra??o albumina, esta apresentou alta atividade inibit?ria de tripsina (100%) e, em menor grau, inibi??o de quimotripsina (28,3%), n?o sendo detectada atividade hemaglutinante. Os resultados obtidos s?o indicativos da a??o negativa dos inibidores de tripsina no crescimento dos animais, no entanto n?o se pode descartar a possibilidade de uma a??o sinerg?stica com outros fatores antinutricionais, que comprometem a utiliza??o da linha?a crua como um alimento alternativo
5

Age-related digestive alterations and their impact on nutrients digestibility

Hernández Olivas, Ever 25 October 2021 (has links)
Tesis por compendio / [ES] El envejecimiento poblacional es un fenómeno sin parangón en la historia de la humanidad. Así, se espera que las personas mayores de 65 años, o población sénior, doblen por primera a la población infantil en 2050. Cumplir años implica una serie de cambios a nivel fisiológico que comprenden, entre otros, una pérdida de funcionalidad de los órganos implicados en el proceso digestivo. En este sentido, el estudio de la digestibilidad de nutrientes, principalmente proteínas, y la bioaccesibilidad de determinadas vitaminas y minerales de interés para la salud de la población sénior, son de especial interés. Solo a partir de evidencias científicas será posible establecer recomendaciones nutricionales de ámbito clínico, y diseñar alimentos funcionales orientados a las necesidades específicas de este grupo poblacional. Entre los nutrientes mayoritariamente afectados por las alteraciones digestivas típicas de personas sénior, las proteínas suponen el reto más importante. Se sabe que las alteraciones orales, gástricas e intestinales afectan su digestión y absorción, contribuyendo al declive del estado general de salud, dando lugar a una pérdida de masa muscular, incremento y cambio de distribución de masa lipídica, huesos y articulaciones más débiles, algunas enfermedades metabólicas y cardiovasculares, entre otros cambios de tipo psicológico y social. El objetivo principal de esta tesis doctoral ha sido evaluar el impacto de las diferentes alteraciones que aparecen con la edad a nivel oral, gástrico e intestinal en la digestibilidad de proteínas, grasas y carbohidratos, así como en la bioaccesibilidad de micronutrientes de interés. Concretamente, se han analizado en alimentos ricos en proteína cuyo consumo está recomendado para mayores de 65 años, y que difieren entre sí en el origen de la proteína (pescados, lácteos, huevo, carne, legumbres y cereales). Para alcanzar este objetivo, se recurrió a modelos digestión in vitro en estático los cuales permiten simular, en condiciones controladas de laboratorio, el proceso digestivo de diferentes grupos de población y muestrear de forma no invasiva. Los resultados más relevantes de esta tesis doctoral se presentan en cinco capítulos, abordando en cada grupo alimenticio, la respuesta digestiva derivada tanto de las alteraciones fisiológicas dados en población sénior, como de ciertos factores inherentes al alimento. En cuanto a las alteraciones digestivas propias de la edad, es posible afirmar que las insuficiencias pancreática y biliar fueron las principales encargadas de reducir de forma significativa la extensión de la proteólisis en casi la totalidad de alimentos estudiados. Los resultados indican una mayor digestibilidad proteica en pescados magros, el huevo duro y escalfado, quesos, carnes de pollo y de vacuno, así como legumbres en general. La digestibilidad de las grasas, en cambio, no resultó negativamente afectada. Por otro lado, los quesos, sardina, así como algunos granos de legumbres y cereales contribuirían satisfactoriamente al aporte de calcio bioaccesible en mayor medida que otras matrices alimentarias. En cuanto a las vitaminas liposolubles, la ingesta de salmón y de quesos fueron una excelente fuente tanto de vitamina A como D3 en su forma bioabsorbible; mientras que la bioaccesibilidad de ambas vitaminas en huevo, dependió del método de cocinado. Además, la carne de cerdo brinda el mayor efecto antihipertensivo, mientras que la de pavo ejerce mayor efecto como antioxidante. Por último, la relación aminoácidos esenciales/ no esenciales aumentó en condiciones alteradas al final de la digestión, en comparación con las condiciones estándar de adulto sano. Por lo que, aun con una digestibilidad de proteínas afectada, los digeridos tendrán efecto contra la sarcopenia. / [CA] L'envelliment poblacional és un fenomen sense parangó en la història de la humanitat. Així, s'espera que les persones majors de 65 anys, o població sènior, dobleguen per primera a la població infantil en 2050. Complir anys implica una sèrie de canvis a nivell fisiològic que comprenen, entre altres, una pèrdua de funcionalitat dels òrgans implicats en el procés digestiu. En aquest sentit, l'estudi de la digestibilitat de nutrients, principalment proteïnes, i la bioaccesibilitat de determinades vitamines i minerals d'interès per a la salut de la població sènior, són d'especial interès. Només a partir d'evidències científiques serà útil establir recomanacions nutricionals d'àmbit clínic, i dissenyar aliments funcionals orientats a les necessitats específiques d'aquest grup poblacional. Entre els nutrients majoritàriament afectats per les alteracions digestives típiques de persones sènior, les proteïnes suposen el repte mes important. Se sap que les alteracions orals, gàstriques i intestinals afecten la seua digestió i absorció, contribuint al declivi de l'estat general de salut, donant lloc a una perduda de massa muscular, increment i canvi de distribució de massa lipídica, ossos i articulacions més febles, algunes malalties metabòliques i cardiovasculars, entre altres canvis de tipus psicològic i social. L'objectiu principal d'aquesta tesi doctoral ha sigut avaluar l'impacte de les diferents alteracions que apareixen amb l'edat a nivell oral, gàstric i intestinal en la digestibilitat de proteïnes, greixos i carbohidrats, així com en la bioccesbilitat de micronutrients d'interès, en aliments rics en proteïna el consum de la qual està recomanat per a majors de 65 anys, i que difereixen entre si en l'origen d'aquest macronutrient (peixos, lactis, ou, carn, llegums i cereals). Per a aconseguir aquest objectiu, es va recórrer a models digestió in vitro en estàtic els quals permeten simular, en condicions controlades de laboratori, el procés digestiu de diferents grups de població i mostrejar de forma no invasiva. Els resultats més rellevants d'aquesta tesi doctoral es presenten en cinc capítols, abordant en cada grup alimentós, la resposta digestiva derivada tant de les alteracions fisiològiques donats en població sènior, com d'uns certs factors inherents a l'aliment. Quant a les alteracions digestives pròpies de l'edat, és possible afirmar que les insuficiències pancreàtica i biliar van ser les principals encarregades de reduir de manera significativa l'extensió de la proteòlisien quasi la totalitat d'aliments estudiats. Els resultats indiquen una major digestibilitat proteica en peixos magres, l'ou dur i escalfat, formatges, carns de pollastre i de boví, així com llegums en general. La digestibilitat dels greixos, en canvi, no va resultar negativament afectada. D'altra banda, els formatges, sardina, així com alguns grans de llegums i cereals contribuirien satisfactòriament a l'aportació de calci bioaccesible en major mesura que altres matrius alimentàries. Quant a les vitamines liposolubles, la ingesta de salmó i de formatges van ser una excel·lent font tant de vitamina A com D3 en la seua forma bioabsorbible; mentre que la bioaccesibilitat de totes dues vitamines en ou, va dependre del mètode de cuinat. A més, la carn de porc brinda el major efecte antihipertensiu, mentre que la de polit exerceix major efecte com a antioxidant. Finalment, la relació aminoàcids essencials/ no essencials va augmentar en condicions alterades al final de la digestió, en comparació amb les condicions estàndard d'adult sa. Pel que, fins i tot amb una digestibilitat de proteïnes afectada, els digerits tindran efecte contra la sarcopènia. / [EN] Population aging is a phenomenon unparalleled in human history. It is expected that people over 65 years, or the elderly, will double the child population for the first time by 2050. Turning 65 implies a series of physiological changes that include, among others, a loss of functionality of the organs involved in the digestive process. In this sense, the study of the digestibility of nutrients, mainly proteins, and the bioaccessibility of certain vitamins and minerals of interest for the health of the senior population, are of special interest. Only on the basis of scientific evidence will it be useful to establish nutritional recommendations at the clinical level, and to design functional foods oriented to the specific needs of this population group. Among the nutrients most affected by the common digestive disorders of the elderly, proteins represent the most important challenge. It is known that oral, gastric and intestinal disorders affect their digestion and absorption, contributing to the decline of general health status, resulting in a loss of muscle mass, increase and change of lipid mass distribution, weaker bones and joints, some metabolic and cardiovascular diseases, among other psychological and social changes. The main objective of this doctoral thesis has been to assess the impact of the different alterations appearing with age at oral, gastric and intestinal level on the digestibility of proteins, fats and carbohydrates, as well as on the bioaccessibility of micronutrients of interest, in protein-rich foods whose consumption is recommended for people over 65 years of age, and which differ from each other in the origin of this macronutrient (fish, dairy products, eggs, meat, legumes and cereals). To achieve this objective, in vitro static digestion models were used to simulate, under controlled laboratory conditions, the digestive process of different population groups and to sample in a non-invasive way. The most relevant results of this doctoral thesis are presented in five chapters, addressing in each food group, the digestive response derived both from physiological alterations in the senior population, as well as from certain factors inherent to the food. Regarding the digestive alterations associated with age, it is possible to affirm that pancreatic and biliary insufficiencies were the main responsible for the significant reduction in the proteolysis extent in almost all the studied foods. The results indicate a higher protein digestibility in lean fish, hard-boiled and poached eggs, cheeses, chicken and beef meats, as well as legumes in general. Fat digestibility, on the other hand, was not compromised. Moreover, cheeses, sardines, as well as some legume and cereal grains would contribute to a greater supply of bioaccessible calcium than other food matrices. For fat-soluble vitamins, the intake of salmon and cheeses resulted as excellent sources of both vitamin A and D3 in their bioabsorbable form, while the bioaccessibility of both vitamins in eggs depended on the cooking method. In addition, pork provided the greatest antihypertensive effect, while turkey meat exerted the greatest effect as antioxidant. Finally, the essential/non-essential amino acid ratio increased under altered conditions at the end of digestion, compared to standard healthy adult conditions. Thus, even with impaired protein digestibility, digests will have an effect against sarcopenia. / Hernández Olivas, E. (2021). Age-related digestive alterations and their impact on nutrients digestibility [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/175472 / TESIS / Compendio

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