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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.
21

Evaluation of low phytate barleys and in vitro procedure for predicting phosphorus availability in organic and inorganic sources of phosphorus /

Badresingh, Vera January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 115-127). Also available on the Internet.
22

Evaluation of low phytate barleys and in vitro procedure for predicting phosphorus availability in organic and inorganic sources of phosphorus

Badresingh, Vera January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 115-127). Also available on the Internet.
23

Phosphorus in pig diets : effect of liquid feeding, phosphorus levels and phytase supplementation on digestibility and performance /

Lyberg, Karin, January 2006 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.
24

Phytate phosphorus hydrolysis by microbial phytase in corn-soybean mean diets for pigs /

Liu, Jiazhong, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 163-175). Also available on the Internet.
25

Phytate phosphorus hydrolysis by microbial phytase in corn-soybean mean diets for pigs

Liu, Jiazhong, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 163-175). Also available on the Internet.
26

Efeito da remoção da fonte de zinco da mistura salina da dieta sobre o ganho de peso de ratos wistar e o valor nutritivo da caseina : influencia de adições crescentes de acido fitico / Effect of the removing zinc source of the saline mixture of the diet on profit of weight of Wistar rats and the nutritional value of the casein: influence of increasing additions of phytic acid

Rios, Karina Ribeiro 20 August 2003 (has links)
Orientador: Admar Costa de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T16:25:47Z (GMT). No. of bitstreams: 1 Rios_KarinaRibeiro_M.pdf: 519085 bytes, checksum: 22eba3b1a8c6784f7067751a10db8f1c (MD5) Previous issue date: 2003 / Resumo: O zinco é um mineral que desempenha inúmeras funções biológicas, como catalisador para a atividade de mais de 300 enzimas, constituinte estrutural de muitas proteínas e como regulador na prevenção da formação de radicais livres. Dado a esta multiplicidade funcional, a deficiência de zinco é especialmente crítica em estádios de rápido crescimento e desenvolvimento onde seu requerimento é aumentado, na ingestão alimentar deficiente ou quando ocorre baixa biodisponibilidade do zinco. Com a descoberta da deficiência do mineral em humanos na década de 60 devido ao elevado consumo de ácido fítico por populações do Oriente Médio, os estudiosos acreditavam ser este um fato isolado, até que na década de 90 foi reconhecido como um problema de carência nutricional de ocorrência freqüente em países desenvolvidos. Com vistas a determinar a influência da fonte de zinco da mistura mineral da dieta AIN-93G e de adições de ácido fítico no crescimento e estado nutricional de zinco em ratos Wistar, estudou-se o efeito da suplementação com carbonato de zinco (56 % Zn) e ácido fítico na forma de hexafosfato de mioinositol (IP6), utilizando-se adições crescentes na dieta de caseína. Os resultados mostraram que apesar de o carbonato de zinco (56 % Zn) ter sido removido por 32 dias, não foi observada diferença estatística (p>0,05) para os índices de crescimento (consumo de dieta e ganho de peso) e valor nutritivo da caseína, determinado pelo Quociente de Eficiência da Caseína (PER). A concentração sérica de zinco não diferiu entre os animais do grupo Controle (dieta AIN-93G, 12,2 % de caseína) e os animais do grupo com dieta basal, sem a fonte de zinco da mistura mineral (ZnC03, 56% Zn), sendo a zincemia assegurada pelos 4,2 mg Zn I kg de caseína. Adições crescentes de ZnC03, 56% Zn, até 129,2 mg de zinco I kg de dieta basal durante 8 dias, após a remoção do mineral por 32 dias, resultaram em valores maiores para ganho de peso, porém até o limite de 86,7 mg Zn I kg dieta, correspondendo a um valor máximo de 98,6 gramas de ganho pondera!. A eficiência alimentar apresentou valores maiores a partir de 33,1 mg Zn I kg dieta e a concentração de zinco no soro dos animais, valores maiores para as adições de 65,4 e 129,2 mg Zn/kg dieta. Adições crescentes de ácido fítico à dieta basal, sem o ZnC03, 56 % Zn, da mistura mineral, num período de 32 dias, ocasionaram redução constante nos índices de crescimento (consumo de dieta e ganho de peso), no valor nutritivo da caseína determinado pelo Quociente de Eficiência Líquida da Caseína (NPR) e Quociente de Eficiência da Caseína (PER), no valor nutritivo dietético, determinado pelo Quociente de Conversão Alimentar (QCA) e na concentração sérica de zinco dos ratos. Os valores das digestibilidades (Aparente e Corrigida pela Dieta Aprotéica) não foram comprometidos pelas adições crescentes de fitato. Pelo exposto, pôde ser inferido que o baixo teor de zinco da dieta basal (1,1 mg Zn I kg dieta) praticamente não afetou o crescimento dos ratos, enquanto a influência de adições crescente de ácido fítico teve um efeito de notável redução dos índices determinados, com exceção da digestibilidade da caseína, num período experimental de 32 dias / Abstract: Zinc is a mineral with a variety of biological functions such as catalyzing the activity of more than 300 enzymes, being a structural constituent of many proteins and as a regulator in the prevention of free radical formation. Due to this functional multiplicity, a deficiency of zinc becomes especially critical during rapid growth and development stages where the requirement is even greater, in cases of deficient feeding or in cases of low zinc bioavailability. In the sixties, when deficiency of this mineral was first discovered in humans, due to the high ingestion of phytic acid by Middle Eastern populations, researchers believed this to be an isolated case. However, in the nineties it was recognized as a malnutritional problem, occurring mainly in large countries. With the objective of determining the influence of the zinc source in the mineral mixture of the AIN-93G diet, and of additions of phytic acid on the growth and nutritional state of zinc in Wistar rats, the effect of supplementation with zinc carbonate (56% Zn) was studied, and also the addition of phytic acid in the form of myoinositol hexaphosphate (IP6), adding increasing amounts to the casein diet. The results show that despite the zinc carbonate (56% Zn) having been removed from the diet for 32 days, no significant (p>0.05) difference was observed with respect to the growth indexes (diet consumption and weight gain) or nutritive value of the casein, as determined from the Protein Efficiency Ratio (PER). There was no difference in serum zinc concentration between that of the Control group of animals (AIN-93G diet, 12.2% casein) and that of the animals on the basal diet, without the source of zinc in the mineral mixture (ZnCO3, 56% Zn), zincemia being guaranteed by the 4.2 mg Zn I kg casein. Increasing additions of ZnCO3, 56% Zn, up to 129.2 mg zinc I kg basal diet for 8 days, after removing the mineral for 32 days, resulted in an increased weight gain, although only up to a limit of 86.7 mg Zn I kg diet, corresponding to a maximum pondered weight gain of 98.6 grams. Higher values for food efficiency were shown as from 33.1 mg Zn I kg diet, and higher values for the concentration of zinc in the animal serum were shown with additions of from 65.4 to 129.2 mg Zn I kg diet. Increasing additions of phytic acid to the basal diet containing no ZnCO3, 56% Zn in the mineral mixture, for a period of 32 days, led to constant reductions in the growth indexes (diet consumption and weight gain), in the nutritive value of the casein as determined by the net protein ratio (NPR) and protein efficiency ratio (PER), in the dietary nutrition value as determined by the food conversion ratio (FCR) and in the serum zinc concentration of the rats. The values for digestibility (apparent and corrected according to the aproteic diet) were unaffected by the increasing additions of phytate. From the results, it can be inferred that the low level of zinc in the basal diet (1.1 mg Zn I kg diet) showed practically no influence on the growth of the rats, whereas in an experimental period of 32 days, there was a notable effect in the reduction of the indexes determined, with the exception of that of casein digestibility, with increasing additions of phytic acid / Mestrado / Mestre em Alimentos e Nutrição
27

Flame retardant treated wood : An investigation into phytic acid and its ability to act as a flame retardant agent

Ström, Mattias, Paulusson, Herman January 2023 (has links)
Flame-retardant coatings have been serving their purpose since the romans ruled Europe. These products have been developed through the years, by mixing and synthetizing solutions, which have resulted in effective, although questionable, products due to their impact on the environment and our health. This matter has been addressed earlier, predominantly regarding fabrics. Now is the time to approach this issue by finding an environmentally and health friendly flame-retardant, that can be applied on wood. Phytic acid is a phosphorus based organic compound which is found abundant in nature and could potentially act as a non-toxic flame-retardant. The acid can form other complexes which could add additional flame-retardant mechanisms and desired characteristics of a flame-retardant. This potential flame-retardant was investigated using two different methods. The first method includes two test series which sought to explain how properties as concentration of phytic acid, pH and different additives affected flame-retardant behaviour. The first method was later changed and refined into the second method, to add higher reliability and validity to the conducted tests. The new method implemented additional analytical methods such as differential scanning calorimetry and nuclear magnetic resonance spectroscopy to investigate particular compounds. The results from the thermogravimetric analysis show that wood samples which were coated with the flame-retardant, had twice the mass percentage remaining compared to the untreated wood samples.
28

Identification and Characterization of Late Pathway Enzymes in Phytic Acid Biosynthesis in Glycine max

Stiles, Amanda Rose 23 August 2007 (has links)
Phytic acid, also known as myo-inositol hexakisphosphate or Ins(1,2,3,4,5,6)P6, is the major storage form of phosphorus in plant seeds. Phytic acid is poorly digested by non-ruminant animals such as swine and poultry, and it chelates mineral cations including calcium, iron, zinc, and potassium, classifying it as an anti-nutrient. The excretion of unutilized phytic acid in manure translates to an excess amount of phosphorus runoff that can lead to eutrophication of lakes and ponds. Understanding the phytic acid biosynthetic pathway will allow for the development of low phytic acid (lpa) soybeans by the down-regulation of specific genes. The goal of this research was to elucidate the pathway(s) for phytic acid biosynthesis in soybean (Glycine max). We have isolated several myo-inositol phosphate kinase genes in soybean as possible candidates for steps in the biosynthetic pathway. We have characterized the genes for four myo-inositol(1,3,4)P3 5/6-kinases (GmItpk1-4), one myo-inositol(1,4,5)P3 6/3/5-kinase (GmIpk2), and one myo-inositol(1,3,4,5,6)P5 2-kinase (GmIpk1). We have examined expression in developing seeds and other tissues by Northern blot analysis and quantitative RT-PCR. We have expressed all six genes as tagged fusion proteins in E. coli, and verified enzyme activity on the proposed substrates. For each enzyme, we have conducted biochemical characterization to determine enzyme kinetics and substrate specificities. We have verified in vivo activity of GmIpk2 and GmIpk1 by complementing yeast mutants in the respective genes. Our studies indicate the likelihood that three of the genes may be involved in phytic acid biosynthesis: GmItpk3, GmIpk2 and GmIpk1. For future work, to more fully understand the contribution of each kinase gene to phytic acid biosynthesis, an RNA interference approach will be employed. The gene sequences identified in this study will be used to construct silencing vectors for use in future transformation of soybean embryogenic cultures to determine the effects of down-regulation on myo-inositol phosphate profiles. / Ph. D.
29

Effects of diet on phosphorus digestion in dairy cattle

Yang, Tzu-Hsuan 02 October 2006 (has links)
Two studies were conducted to evaluate the effects of diet on phosphorus (P) digestion in dairy cattle. The objective of the first study was to evaluate the effects of forage and non-fiber carbohydrate (NFC) content on total P (TP) and inositol phosphates-P (IPs-P) digestion. Samples of feed, duodenal digesta and feces from a previously conducted study were analyzed for TP and IPs-P. In this study, eight lactating Holstein cows were fed diets containing either 60 or 35% forage and either 30 or 40% NFC in a 2 × 2 factorial with replicated 4 × 4 Latin square design. Dietary TP content (% DM) was 0.35, 0.36, 0.36, 0.36 and dietary IPs-P content (%DM) was 0.08, 0.13, 0.06, 0.11 for diets with forage: NFC ratio 35:30, 35:40, 60:30, and 60:40, respectively. Increasing dietary forage content decreased IPs-P and TP intake, fecal TP excretion, and total tract IPs-P digestibility (72.4 vs. 61.4%). Fecal IPs-P excretion tended to decrease as increasing forage content. Duodenal IPs-P and TP flow and apparent TP digestibility were unaffected by forage content. Increasing dietary NFC content increased IPs-P and TP intake, duodenal IPs-P flow, fecal IPs-P excretion, total tract IPs-P digestibility (61.4 vs. 72.4%), and apparent TP digestibility (32.8 vs. 41.6%). Dietary forage and NFC content affected IPs-P and TP digestion. The second study was to evaluate the effects of increasing dietary beet pulp (BP) content to replace high moisture corn (HMC) on ruminal and post-ruminal digestion of TP and IPs-P. Eight lactating Holstein cows were fed diets containing 0, 6.1, 12.1 or 24.3% BP in a replicated 4 × 4 Latin square design. Samples of rumen contents, duodenal digesta, and feces from this previously conducted study were analyzed for TP and IPs-P content. Linear and quadratic effects of BP content were analyzed using Proc Mixed of SAS. Dietary TP and IPs-P content were reduced linearly with increasing BP (0.59, 0.58, 0.57, 0.56% TP and 0.15, 0.14, 0.13, 0.11% IPs-P). Intake, ruminal content, and rumen pool size of TP decreased with increasing BP content. Digestion of TP and duodenal flow and fecal excretion of IPs-P and TP were not affected. With increasing dietary BP content, IPs-P intake was reduced, ruminal IPs-P pool size was reduced, and rumen turnover time (h) of IPs-P was increased. Apparent ruminal IPs-P digestibility (36.5, 31.8, 24.6, 13.6 %) and apparent total tract IPs-P digestibility (85.3, 82.7, 82.1, 79.1%) decreased linearly with increasing BP. Fecal excretion of IPs-P averaged 5.2 g/d. Replacing HMC with BP reduced digestion of IPs-P. The majority of IPs-P disappearance occurred post-ruminally. In conclusion, dietary BP, forage, and NFC content affected IPs-P digestion in dairy cows. / Master of Science
30

Detoxification and nutritional enhancement of soy meal via microbial bioprocessing

Chen, Liyan January 1900 (has links)
Doctor of Philosophy / Department of Grain Science and Industry / Praveen V. Vadlani / Soy meal (SM) is the main protein source for monogastric animals. Anti-nutritional factors in SM limited its usage for young monogastric animals. Aspergillus was investigated to degrade these factors and to enhance its nutritional value via solid state fermentation. Galacto-oligosaccharides were totally degraded from the initial 9.48 mmol/100 g, and trypsin inhibitor decreased from 10.7 TIU/mg to a non-detectable level after 36 hr fermentation. Structural polysaccharides decreased by 59% (w/w) and the degree of hydrolysis of SM protein increased from 0.9% to 7% (w/w) through the 7 d fermentation. Fermentation also modified nutritional factors. Protein content increased from 50.47% (w/w) to 58.93% (w/w) after 36 hr fermentation. Amino acid profile was significantly enhanced. Two - stage temperature-induced fermentation protocol was developed to increase the degradation rate of phytic acid by A. oryzae (ATCC 9362) and by A. ficuum (ATCC 66876). The first stage maximized phytase production with fermentation parameters obtained by central composite design. The second stage achieved maximum enzymatic degradation with parameters obtained by studying the phytase temperature characteristics. While using A. oryzae, 57% of phytic acid in SM was degraded by the two stage protocol compared to 39% degradation from single stage fermentation. For A. ficuum, the two-stage temperature fermentation protocol achieved a 98% degradation level of phytic acid degradation compared with the single stage process. Two-stage temperature-induced co-fermentation of A. oryzae and A. ficuum was investigated to simultaneously degrade phytic acid and soy protein with high efficiency. Co-fermentation of A. oryzae and A. ficuum resulted in higher phytic acid degradation than A. oryzae fermentation and superior protein hydrolysis compared to A. ficuum fermentation. Sterilization distorted the results of fermentation effect on soy allergens and soy protein degradation. Virginiamycin is a kind of bacterisin. It was added to A. oryzae solid state fermentation, to exclude the necessity of SM sterilization. Nonsterile, solid state fermentation using A. oryzae and virginiamycin showed the complete degradation of α and α’ subunits of β-conglycinin and decreased immunoreactivity of soy protein. The modified SM after microbial bioprocessing created an innovative product with enhanced characteristics with potential wider applications for feed industry.

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