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Phytate
Kinds of Phytate Terms modified by Phytate Selected AbstractsPhytate and mineral content in different milling fractions of some Pakistani spring wheatsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2002Faqir M. Anjum Six Pakistani wheat cultivars, namely C-273, Inqulab-91, Pasban-90, Parwaz-94, Shahkar-95 and Rohtas-90, were included in the present study. The kernel weight of the wheat cultivars varied from 31.43 to 36.76 g (per thousand kernels), Parwaz-94 having the highest and Rohtas-90 having the lowest. The test weight of cultivars ranged from 70.23 (Shakar-95) to 76.13 kg hL,1 (Pasban-90). The bran contained the highest amount of phytic acid (6.12%) in C-273 followed by whole-wheat flour (2.23%) in Inqulab-91, and straight-grade flour (0.24%) in Parwaz-94. The phytate content was reduced during the baking of bread and chapati. The bread scores and other quality characteristics varied significantly among cultivars. The total bread scores ranged from 35.20 to 42.00, out of a possible fifty, with Parwaz-94 being the highest. The concentration of minerals varied widely in different milling fractions of various wheat cultivars. The concentration of Cu, Fe, Mn and Zn ranged from 5.00 to 52.50, 26 to 147.50, 0.00 to 97.00, 9.0 to 80.80 ppm, respectively, in different milling fractions of the wheat cultivars. The total chapati scores ranged from 22.40 to 24.20 of a possible score of 30. The minimum chapati scores were found in Rohtas-90 and Parwaz-94, while Inqulab-91 produced the maximum score. [source] The Localization of Phytate in Tofu Curd Formation and Effects of Phytate on Tofu TextureJOURNAL OF FOOD SCIENCE, Issue 2 2008T. Ishiguro ABSTRACT:, The localization of phytate on tofu making and its effects on tofu texture were investigated. Thirty-eight percent and 3% of phytate in soymilk were bound to soluble protein and particulate protein, respectively, and the others were in free form. In the early stage of curd formation, phytate bound to particulate proteins and then a large part of phytate was taken into the tofu curd. Increase of phytate contents in soymilk resulted in the increase of coagulant requirement to make firm tofu. Optimal coagulant concentration (OCC) for making tofu was influenced by phytate contents. The increase of phytate in tofu caused decrease of hardness at OCC and resulted in the increase of brittleness and viscosity of tofu. We concluded that the phytate content is one important factor that contributes to tofu texture. [source] Interaction of phytate with protein and minerals in a soybean,maize meal blend depends on pH and calcium additionJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2007Katrine Pontoppidan Abstract In order to investigate possible interactions of phytate with protein and minerals in simplified animal diets, studies were conducted on the solubility of endogenous phytate, protein and essential minerals in a soybean,maize meal blend within a physiological relevant pH range. The blend was mixed with water for 10 min and then allowed to incubate at 40 °C (30 min) after adjustment of the pH. Finally, soluble phytate, protein, zinc, manganese and iron were determined. Phytate and mineral solubility was highly influenced by pH whereas protein solubility was less affected. Addition of 5 g Ca2+ kg,1 drastically reduced the solubility of phytate, zinc, manganese and iron at pH above 4.4, indicating that the formation of insoluble phytate,mineral complexes is increased in the presence of calcium. The action of pepsin increased the solubility of protein and phytate at pH below 4, indicating that insoluble phytate,protein complexes are present at low pH. Calcium had the same solubilising effect as pepsin at pH 2,4 but to a lesser degree. Copyright © 2007 Society of Chemical Industry [source] Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysisMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue S2 2009Ulrich Schlemmer Abstract The article gives an overview of phytic acid in food and of its significance for human nutrition. It summarises phytate sources in foods and discusses problems of phytic acid/phytate contents of food tables. Data on phytic acid intake are evaluated and daily phytic acid intake depending on food habits is assessed. Degradation of phytate during gastro-intestinal passage is summarised, the mechanism of phytate interacting with minerals and trace elements in the gastro-intestinal chyme described and the pathway of inositol phosphate hydrolysis in the gut presented. The present knowledge of phytate absorption is summarised and discussed. Effects of phytate on mineral and trace element bioavailability are reported and phytate degradation during processing and storage is described. Beneficial activities of dietary phytate such as its effects on calcification and kidney stone formation and on lowering blood glucose and lipids are reported. The antioxidative property of phytic acid and its potentional anticancerogenic activities are briefly surveyed. Development of the analysis of phytic acid and other inositol phosphates is described, problems of inositol phosphate determination and detection discussed and the need for standardisation of phytic acid analysis in foods argued. [source] Growth of the vacuoleless mutant of Tetrahymena thermophila NP1 in phytateTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2005SAMANTHA WEBB Phytate, the salt form of phytic acid, is the major store of phosphate in seeds and grain. Since non-ruminant farm animals poorly digest phytate, it is also a source of environmental phosphate contamination in agricultural areas. We are using Tetrahymena, a ciliated protist with multiple routes for nutrient assimilation, as a model to investigate the contribution of heterotrophic protists to the environmental cycling of phosphate from phytate. This ciliate has the ability to grow on phytate as the sole phosphate source (Ziemkiewicz, H. T., Johnson, M. D. & Smith-Somerville, H. E. 2002. J. Eukaryot. Microbiol., 49:428). Tetrahymena thermophila NP1, a temperature-sensitive vacuoleless mutant (ATCC #50202), provides a way to separate membrane transport from uptake through phagosomes, and to assess the importance of each mechanism. This cell grows equally well at the permissive and non-permissive temperatures with either phytate or inorganic phosphate as the phosphate source. Our results demonstrate that phagosomes are not required to use the phosphate from phytate. [source] Phytate prevents tissue calcifications in female ratsBIOFACTORS, Issue 3 2000F. Grases The AIN-76 A, a purified rodent diet, has a propensity to cause kidney calcifications in female rats which is not observed with non-purified rodent diets, suggesting a nutritional factor that avoids these calcifications. One candidate is phytate, which inhibits crystallisation of calcium salts and is practically absent in purified diets. Therefore, the effects on calcification of kidney tissue of phytate addition to the AIN-76 A diet using female Wistar rats were studied. The rats were assigned to three groups: AIN-76 A, AIN-76 A + 1% phytate and standard nonpurified chow. Urinary phytate of the AIN-76 A fed group was undetectable. Urinary phytate of AIN-76 A + 1% phytate and standard fed groups did not differ and was significantly higher than in the AIN-76 A group. The concentrations of calcium and phosporus in kidneys were greater in the AIN-76 A group than in AIN-76 A + 1% phytate and standard groups. Only rats of the AIN-76 A group displayed mineral deposits at the corticomedullary junction. These findings demonstrated that the absence of phytate in the AIN-76 A diet is one of the causes of renal calcification in female rats. [source] Structure of Debaryomyces castellii CBS 2923 phytaseACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2009M. Ragon Phytate (myo -inositol hexakisphosphate) is the primary storage form of phosphate in seeds and legumes (Reddy et al., 1982). Phytases are phosphatases that hydrolyze phytate to less phosphorylated myo -inositol derivatives and inorganic phosphate. The crystal structure of phytase from Debaryomyces castellii has been determined at 2.3,Å resolution. The crystals belonged to space group P6522, with unit-cell parameters a = 121.65, c = 332.24,Å. The structure was solved by molecular replacement and refined to a final R factor of 15.7% (Rfree = 20.9%). The final model consists of a dimer (with two monomers of 458 residues), five NAG molecules and 628 water molecules. [source] Rapid decomposition of phytate applied to a calcareous soil demonstrated by a solution 31P NMR studyEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2010A. L. Doolette myo -Inositol hexakisphosphate (phytate) is widely regarded as an abundant form of soil organic phosphorus (P) in many soils. Its abundance is believed to be because of its resistance to microbial degradation. We examined the fate of phytate added to a calcareous soil as a solution at a concentration of 58 mg P kg,1, with and without the addition of wheat straw. The soil was incubated for 13 weeks, with phytate concentrations determined at 0, 1, 4, 7 and 13 weeks using NaOH-EDTA soil extraction followed by 31P nuclear magnetic resonance (NMR) spectroscopy. The phytate concentration declined rapidly, with 18% (phytate + wheat straw) and 12% (phytate) of the initial phytate remaining after 13 weeks. This coincided with an increase in the proportion of orthophosphate relative to total NaOH-EDTA extractable P (from 65 to 81%) and a small increase in , - and , -glycerophosphate concentration, providing evidence for the microbial degradation of phytate. The decrease in phytate concentration was consistent with a first-order decay with a half-life for phytate of 4,5 weeks. This study demonstrates that in the calcareous soil examined, phytate was not highly stable, but a potentially biologically available form of P. In order to quantify the concentration of P species, we developed an improved method of spectral deconvolution. This method accounted for a broad signal (3.5,6.5 ppm) in the monoester region of the spectra that represented up to 23% of the total extractable P. We found that when this broad signal was not included, phytate concentrations were over-estimated by up to 54%. [source] Efficiency of acid phosphatases secreted from the ectomycorrhizal fungus Hebeloma cylindrosporum to hydrolyse organic phosphorus in podzolsFEMS MICROBIOLOGY ECOLOGY, Issue 2 2010Julien Louche Abstract Ectomycorrhizal fungi may improve the phosphate nutrition of their host plants by secreting, into the soil solution, acid phosphatases (AcPases) able to release orthophosphate (Pi) from soil organic phosphorus (Po). Using cation-exchange chromatography, we separated four fractions with AcPase activity secreted by the ectomycorrhizal fungus Hebeloma cylindrosporum grown in a pure culture under P-starved conditions. Each AcPase active fraction displayed strong ability in vitro to hydrolyse a wide range of phosphate monoesters, but none of them efficiently hydrolysed phytate. Their efficiency to release Pi from soil NaHCO3 -extractable Po was studied in a sandy podzol used intact or autoclaved. Soils were collected in a 15-year-old Pinus pinaster stand, receiving regular fertilization or not. Autoclaving increased the NaHCO3 -extractable Po concentrations by 55% in unfertilized and by 32,43% in fertilized soils. The efficiency of each AcPase fraction was affected significantly by the soil fertilization regime and the soil treatment (intact vs. autoclaved). The proportion of labile Po enzyme ranged from 0% to 11% and 14% to 48% after 1 h of incubation in bicarbonate solutions extracted from intact and autoclaved soils, respectively. This work suggests that AcPases secreted from H. cylindrosporum could be efficient in recycling Po pools from soil microorganisms that may be delivered by soil autoclaving. [source] Effect of malt pretreatment on phytate and tannin level of two sorghum (Sorghum bicolor) cultivarsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2006Wisal H. Idris Summary The seeds of two cultivars of Sudanese sorghum (Sorghum bicolor), namely Wad Ahmed and Tabat, were germinated for 4 days to obtain 1-, 2- and 4-day-old malts. Sorghum malt (5% and 10%) was added to sorghum flour. The mixtures were incubated at 30 °C with shaking for 30, 60, 90 and 120 min. Malting loss was very slight for both cultivars and for all incubation periods. Phytic acid and tannin contents were assayed for all treatments. The results revealed that phytate and tannin contents were significantly (P , 0.05) reduced when sorghum flour was pretreated with malt. When a mixture containing 10%, 4-day-old malt and sorghum flour was incubated for 120 min, it significantly (P , 0.05) reduced phytate and tannin contents by 92% and 98%, respectively, for Wad Ahmed cultivar, while for Tabat they were reduced by 93% and 96%, respectively. The rate of reduction of phytate and tannin content increased with incubation time and malt age and concentration. [source] Dietary phytate (inositol hexaphosphate) regulates the activity of intestinal mucosa phytaseJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5 2009E. M. Onyango Summary The role of dietary phytate (inositol hexaphosphate) in the regulation of intestinal mucosa phytase was investigated in chicks. Seven-day-old chicks were grouped by weight into six blocks of three cages with six birds per cage. Three purified diets [a chemically defined casein diet, a chemically defined casein diet plus sodium phytate (20 g/kg diet) and a chemically defined casein diet plus sodium phytate (20 g/kg diet) and microbial phytase (1000 units/kg diet)] were randomly assigned to cages within each block. Chicks were fed experimental diets from 8 to 22 days of age then killed, and duodenal mucosa and left tibia removed. Phytase activity in duodenal mucosa, growth performance and bone ash content were determined. Addition of phytate to the chemically defined casein diet reduced (p < 0.05) the Vmax of the duodenal brush border phytase, but the Km of the enzyme was not affected. Addition of phytate also reduced (p < 0.05) weight gain, feed intake, feed efficiency and percentage ash. Addition of microbial phytase fully restored the feed efficiency (p < 0.05), but Vmax and body weight gain were only partially restored (p < 0.05). In conclusion, it would seem that dietary phytates non-competitively inhibit intestinal mucosa phytase. [source] Effect of sodium phytate supplementation on fat digestion and cholesterol metabolism in female ratsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 11-12 2005C. Yuangklang Summary The effects of sodium phytate supplementation on fat digestion and cholesterol metabolism were investigated in female rats. On the basis of an in vitro experiment showing that phytate raised the solubility of bile acids, it was predicted that phytate feeding would depress faecal bile acid excretion, raise apparent fat digestibility and elevate serum cholesterol concentrations. The experimental diets with or without sodium phytate were either cholesterol-free or cholesterol-rich and had a normal calcium concentration. Rats fed on the cholesterol-rich diet with sodium phytate showed enhanced faecal bile acid excretion, but there was no effect on fat digestibility. In rats fed the cholesterol-free diets, phytate did neither affect fat digestion nor bile acid excretion. Sodium phytate inclusion in the cholesterol-rich diet raised serum cholesterol concentrations, but reduced liver cholesterol concentration. Thus, the in vivo data do not agree with the in vitro observations. Both phytate and cholesterol feeding influenced mineral and trace element metabolism. Liver zinc concentrations were raised by phytate feeding. Cholesterol consumption reduced hepatic concentrations of copper, iron and zinc. Both phytate and cholesterol feeding reduced the apparent absorption of calcium, magnesium and phosphorus. [source] Cloning and expression of Bacillus phytase gene (phy) in Escherichia coli and recovery of active enzyme from the inclusion bodiesJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2008D.E.C.S. Rao Abstract Aims:, To isolate, clone and express a novel phytase gene (phy) from Bacillus sp. in Escherichia coli; to recover the active enzyme from inclusion bodies; and to characterize the recombinant phytase. Methods and Results:, The molecular weight of phytase was estimated as 40 kDa on SDS-polyacrylamide gel electrophoresis. A requirement of Ca2+ ions was found essential both for refolding and activity of the enzyme. Bacillus phytase exhibited a specific activity of 16 U mg,1 protein; it also revealed broad pH and temperature ranges of 5·0 to 8·0 and 25 to 70°C, respectively. The Km value of phytase for hydrolysis of sodium phytate has been determined as 0·392 mmol l,1. The activity of enzyme has been inhibited by EDTA. The enzyme exhibited ample thermostability upon exposure to high temperatures from 75 to 95°C. After 9 h of cultivation of transformed E. coli in the bioreactor, the cell biomass reached 26·81 g wet weight (ww) per l accounting for 4289 U enzyme activity compared with 1·978 g ww per l producing 256 U activity in shake-flask cultures. In silico analysis revealed a ,-propeller structure of phytase. Conclusions:, This is the first report of its kind on the purification and successful in vitro refolding of Bacillus phytase from the inclusion bodies formed in the transformed E. coli. Significance and Impact of the Study:, Efficient and reproducible protocols for cloning, expression, purification and in vitro refolding of Bacillus phytase enzyme from the transformed E. coli have been developed. The novel phytase, with broad pH and temperature range, renaturation ability and substrate specificity, appears promising as an ideal feed supplement. Identification of site between 179th amino acid leucine and 180th amino acid asparagine offers scope for insertion of small peptides/domains for production of chimeric genes without altering enzyme activity. [source] Phytate degradation by micro-organisms in synthetic media and pea flourJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2002M. Fredrikson Aims: To screen micro-organisms for the ability to produce phytase enzyme(s) and to use promising strains for the fermentation of pea flour. Methods and Results: Two methods using the indirect estimation of phytate degradation were evaluated and both shown to be inadequate. A third method, measuring the inositol phosphate (IP3,IP6) content directly during fermentation, was used instead of the indirect estimations of phytate degradation. In synthetic media, some strains required customized conditions, with no accessible phosphorus sources other than phytate, to express phytase activity. The repression of phytase synthesis by inorganic phosphorus was not detected during fermentation with pea flour as substrate and seemed to be less significant with a higher composition complexity of the substrate. None of the tested lactic acid bacteria strains showed phytase activity. Conclusions: The methodology for the phytase screening procedure was shown to be critical. Some of the screening methods and media used in previous publications were found to be inadequate. Significance and Impact of the Study: This paper highlights the pitfalls and difficulties in the evaluation of phytase production by micro-organisms. The study is of great importance for future studies in this area. [source] OPTIMAL COAGULANT CONCENTRATION, SOYMILK AND TOFU QUALITY AS AFFECTED BY A SHORT-TERM MODEL STORAGE OF PROTO SOYBEANSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2008ZHI-SHENG LIU ABSTRACT Soybeans were adjusted to water activities (Aw) from 0.60 to 0.81, and stored at 30C for up to 3 months. At 1-month intervals, soybeans were retrieved from the storage and processed into 10.5 Brix soymilk. The optimal coagulant concentration (OCC) for making filled tofu was determined using a titration method. Other soymilk characteristics, including total solids, protein, 11 S/7 S protein ratio, phytate, titratable acidity, pH and color, were also determined. Filled tofu was prepared from each stored soybeans with the respective OCC using MgCl2 or CaCl2. With increasing Aw or storage time, the OCC decreased significantly. The decrease in OCC was significantly correlated to the difference in soymilk titratable acidity and the change in soymilk pH. Soybean storage time slightly decreased the breaking stress and apparent Young's modulus of the filled tofu, particularly the MgCl2 coagulated tofu. With increasing Aw or storage time, the lightness and yellowness intensity of both soymilk and tofu decreased, whereas their redness intensity increased. PRACTICAL APPLICATIONS Tofu and soymilk are popular soybean foods. Using optimal concentration of coagulant in soymilk is the most critical step among many steps of unit operations during tofu manufacturing for achieving high quality tofu. Improper use of coagulant can lead to product failure and therefore significant economic loss for the manufacturers. The optimal coagulant concentration varies not only with processing condition, but also with soybean materials which are affected by variety and storage conditions. Acidity, pH and food color are important quality factors to influence taste and consumer acceptance. Soybeans are subject to storage and transportation before processing. Storage length and environmental humidity are two of important factors which affect soybean quality and processing property. This study provides very important information that is useful for the soymilk and tofu manufacturers in controlling product quality through the understanding of the chemistry and processing characteristics of stored soybeans. Manufacturers can utilize the methods presented in this article to calculate the optimal coagulant concentrations to avoid product failure and to produce the best quality products. [source] PROCESSING OF FOXTAIL MILLET FOR IMPROVED NUTRIENT AVAILABILITYJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2006VITHAL DEORAO PAWAR ABSTRACT Foxtail millet grains were soaked in distilled water (1:5, w/v) for 12 h at room temperature, dehulled; dehulled and soaked; and dehulled, soaked and cooked in distilled water (1:3, w/v), and the effects of removal of polyphenols and phytate on the in vitro protein digestibility (IVPD) and availability of iron and zinc were measured. The results showed that polyphenols and phytate were decreased significantly up to 50.92 and 49.89%, respectively. The IVPD, however, increased up to 38.71%. The iron and zinc contents decreased up to 18.79 and 18.61%, respectively, but the ionizable iron and zinc were increased up to 55.45 and 80.18%, respectively. This indicated the suitability of simple processing techniques for improvement of availability of nutrients from foxtail millet. [source] Calcium Absorption from Commonly Consumed Vegetables in Healthy Thai WomenJOURNAL OF FOOD SCIENCE, Issue 9 2008S. Charoenkiatkul ABSTRACT:, The absorbability of calcium from ivy gourd, a green leafy vegetable (Coccinia grandix Voigt.) and winged bean young pods (Psophocarpus tetragonolobus [L] DC) were measured in 19 healthy adult women aged 20 to 45 y, in a 3-way, randomized-order, crossover design with an average calcium load of 100 mg and milk as the referent. The test meals were extrinsically labeled with 44Ca and given with rice as breakfast after an overnight fast. Absorption of calcium was determined on a blood sample drawn 5 h after ingestion of the test meal. Fractional calcium absorption (X± SD) was 0.391 ± 0.128 from winged beans, 0.476 ± 0.109 from ivy gourd, and 0.552 ± 0.119 from milk. The difference in fractional calcium absorption for these 2 vegetables was significant (P < 0.05) and the fractional calcium absorption from these 2 vegetables were both significantly lower than from milk. The difference was partly accounted for by the phytate, oxalate, and dietary fiber content of the vegetables. However, calcium bioavailability of these 2 vegetables, commonly consumed among Thais, was relatively good compared to milk (71% to 86% of milk) and could be generally recommended to the public as calcium sources other than milk and Brassica vegetables. [source] A Soybean Cultivar Lacking Lipoxygenase 2 and 3 Has Similar Calcium Bioavailability to a Commercial Variety Despite Higher Calcium Absorption InhibitorsJOURNAL OF FOOD SCIENCE, Issue 3 2008H.S.D. Martino ABSTRACT:, The aim of this study was to evaluate calcium bioavailability of a new soybean variety without 2 lipoxygenases with better taste and flavor than a commercial variety containing all 3 isozymes. Using the femur 45Ca uptake method, calcium absorption from a new Brazilian variety, UFV-116, was compared to a common Brazilian variety, OCEPAR 19. Male Sprague,Dawley growing rats weighing 150 to 170 g (10/group) received test meals of whole fat soy flour prepared from UFV-116 or OCEPAR-19 seeds labeled with 10 ,Ci of 45Ca. Femurs were removed after 48 h for determination of 45Ca uptake. Calcium fractional absorption was equivalent between the 2 varieties. The higher oxalate:calcium molar ratio and the higher content of oxalate and phytate (P < 0.05) found in the UFV-116 variety did not affect calcium absorption. Therefore, the new variety is a comparable source of high bioavailable calcium. [source] The Localization of Phytate in Tofu Curd Formation and Effects of Phytate on Tofu TextureJOURNAL OF FOOD SCIENCE, Issue 2 2008T. Ishiguro ABSTRACT:, The localization of phytate on tofu making and its effects on tofu texture were investigated. Thirty-eight percent and 3% of phytate in soymilk were bound to soluble protein and particulate protein, respectively, and the others were in free form. In the early stage of curd formation, phytate bound to particulate proteins and then a large part of phytate was taken into the tofu curd. Increase of phytate contents in soymilk resulted in the increase of coagulant requirement to make firm tofu. Optimal coagulant concentration (OCC) for making tofu was influenced by phytate contents. The increase of phytate in tofu caused decrease of hardness at OCC and resulted in the increase of brittleness and viscosity of tofu. We concluded that the phytate content is one important factor that contributes to tofu texture. [source] Fermentation of soybean by Rhizopus promotes the calcium absorption ratio in ratsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2008Nakamichi Watanabe Abstract BACKGROUND: Soy foods are generally considered to be an unfavourable source of calcium because soybean is rich in phytate, which retards the absorption of calcium. The objective of this study was to assess the effect of dietary fermented soybean, such as tempeh, on calcium absorption in rats. The rats were grouped into three dietary groups and fed the experimental diets for 4 weeks. Soybean, conventional tempeh prepared by aerobic fermentation with Rhizopus (tempeh), and novel tempeh prepared by aerobic and successive anaerobic fermentations (anaerobic tempeh) were used as the protein sources of the experimental diets. RESULTS: The order of the calcium absorption ratio for the 3 days before the end of the test period was as follows: tempeh group > anaerobic tempeh group > soybean group. CONCLUSION: The calcium absorption ratio of the tempeh group in particular was significantly higher than those of the other two groups. The high calcium absorption ratio of the tempeh group might be caused by both low phytate contents and peptides that are produced during the fermentation of soybean by Rhizopus. Copyright © 2008 Society of Chemical Industry [source] Interaction of phytate with protein and minerals in a soybean,maize meal blend depends on pH and calcium additionJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2007Katrine Pontoppidan Abstract In order to investigate possible interactions of phytate with protein and minerals in simplified animal diets, studies were conducted on the solubility of endogenous phytate, protein and essential minerals in a soybean,maize meal blend within a physiological relevant pH range. The blend was mixed with water for 10 min and then allowed to incubate at 40 °C (30 min) after adjustment of the pH. Finally, soluble phytate, protein, zinc, manganese and iron were determined. Phytate and mineral solubility was highly influenced by pH whereas protein solubility was less affected. Addition of 5 g Ca2+ kg,1 drastically reduced the solubility of phytate, zinc, manganese and iron at pH above 4.4, indicating that the formation of insoluble phytate,mineral complexes is increased in the presence of calcium. The action of pepsin increased the solubility of protein and phytate at pH below 4, indicating that insoluble phytate,protein complexes are present at low pH. Calcium had the same solubilising effect as pepsin at pH 2,4 but to a lesser degree. Copyright © 2007 Society of Chemical Industry [source] Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridgesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2007AP Polycarpe Kayodé Abstract This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of staple food. We studied the example of the West African porridge ,dibou' for which the processing methods involve grain cleaning, milling, sieving and cooking. Regional variations occur in the process, particularly in the cleaning which may be done wet or dry; sieving may be omitted in certain locations. Cleaning reduced the phytate content of the grain by 24,39%, while milling, sieving and cooking had no significant effect on phytate. Phenolic compounds measured as levels of reactive hydroxyl groups, remained constant after cleaning, milling and sieving, but significantly decreased by 38,65% after cooking. The Fe solubility tended to increase after cleaning but was drastically reduced due to cooking, and so was the soluble Zn. Levels of total phenolic compounds highly correlated with the Fe and Zn solubility (r2 = 0.73 and 0.82, respectively). Phenolic reaction products formed during the cooking process are presumably related with the extensive browning phenomenon observed in the dibou porridge, and with the reduction observed in Fe and Zn solubility. Copyright © 2007 Society of Chemical Industry [source] Phytate content and phytate degradation by endogenous phytase in pea (Pisum sativum)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2001Mattias Fredrikson Abstract In order to rapidly reduce the content of inositol tri,hexaphosphates in pea flour by action of the endogenous phytase, raw materials as well as incubation conditions have been evaluated. The phytate (inositol hexaphosphate) content was analysed in 27 pea varieties; the influence of storage time and the difference in phytate content between the germ and the cotyledon were determined. Furthermore, degradation of inositol phosphates by the endogenous phytase enzyme was studied in pea flour, germ and cotyledon. To find the maximum phytate degradation, the effects of temperature and pH during pea flour incubation were investigated. The most efficient phytate degradation in pea flour incubation was achieved at pH 7.5 and 45,°C. At this condition an almost complete degradation of phytate and a 66% reduction in the sum of inositol hexa-, penta-, tetra- and triphosphates were reached in 10,h. The storage time of pea seeds or removal of the germ did not have a major effect on the phytate content. Since several inositol pentaphosphate isomers were produced during phytate degradation, it can be concluded that peas contain several phytate-degrading enzymes, or one phytate-degrading enzyme with unspecific initial hydrolysation pattern. © 2001 Society of Chemical Industry. [source] Effects of Fungal Phytase on Utilization of Dietary Protein and Minerals, and Dephosphorylation of Phytic Acid in the Alimentary Tract of Channel Catfish Ictalurus punctatus Fed an All-Plant-Protein DietJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2002Weibing Yan A feeding trial was conducted to quantify the effects of phytase at levels of 0, 500, 1,000, 2,000, 4,000, and 8,000 units (U) per kg diet on utilization of dietary protein and minerals by fingerling (12 g) channel catfish Ictalurus punctatus fed an all-plant-protein diet composed of soybean meal, corn, and wheat middlings. The effects of phytase on dephosphorylation of phytic acid (phytate) in the alimentary tract of catfish also were determined. After 14 wk, mean weight gains (30.2,43.9 g/fish), feed conversion ratios (2.27,2.40 g feed consumed/g weight gain), protein efficiency ratios (1.47,1.61 g weight gaid/g protein consumed), and dietary protein retentions (23.8,26.7%) did not differ significantly (P > 0.05) among treatment groups. A digestibility trial conducted after the feeding trial showed no difference (P > 0.05) in mean digestibility of diet dry matter (49.0,58.3%) or crude protein (85.4-88.5%) among treatment groups. Concentrations of ash (46.7,48.6%), calcium (Ca, 17.9,18.5%), phosphorus (P, 9.1,9.5%), and manganese (Mn, 65.5,74.1 mg/kg) were significantly higher (P , 0.05) in bone of fish fed , 500 U/kg than in bone of fish fed 0 U/kg (ash, 43.5%; Ca, 16.4%; P, 8.4%; and Mn, 49.0 ma/kg), but concentrations of these minerals did not differ (P > 0.05) in bone of fish fed , 500 Uk/g. The magnesium (Mg) content of bone did not differ (P > 0.05) between fish fed 0 U/kg (0.29%) or 500 U/kg (0.34%), but was significantly lower in fish fed 0 U/kg than in fish fed , 1,000 U/kg (0.35,37%). Bone Mg levels did not differ (P > 0.05) among fish fed , 500 U/kg. The amount of zinc (Zn) in bone of fish fed 8,000 U/kg (153.3 mg/kg) was significantly higher than that in fish fed 0 U/kg (115.7 mg/kg) or 500 U/kg (130.3 mg/ kg), but did not differ from Zn levels in bone of fish fed 1,000,4,000 U/kg (134.5,135.8 mg/ kg). Dephosphorylation of phytate occurred primarily in the stomach within 2,8 h after diet ingestion, depending on the level of phytase supplementation. Initial levels of total phytate in the diet decreased 32,94% in stomach contents of fish fed l,000,8,000 U/kg within 2 h after feeding. Eight hours after feeding, stomach contents of fish fed , 1,000 U/kg contained less than 6% of initial total dietary phytate. Stomach contents of fish fed 500 U/kg retained 92% of initial total dietary phytate 2 h after feeding and 15% of total dietary phytate 8 h after feeding. Results of this study indicate that phytase supplementation at levels up to 8,000 U/kg diet did not increase weight gain or improve dietary protein utilization of channel catfish fed an all-plant-protein diet. Addition of phytase at a level of 1,000 U/kg diet was sufficient to significantly increase the Ca, P, Mg, and Mn content of bone, relative to fish fed an unsupplemented diet, and significantly decrease the quantity of total phytate in feces. A phytase level of 8,000 U/kg diet significantly increased the bioavailability of naturally occurring Zn in feed ingredients and increased the rate of phytate dephosphorylation in the stomach, compared with a diet containing no added phytase. Increased utilization of naturally occurring minerals in feed ingredients reduces the need for mineral supplements in diets and results in decreased elimination of minerals in feces. Thus, use of phytase in catfish feeds can be expected to provide both economic and environmental benefits. [source] Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysisMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue S2 2009Ulrich Schlemmer Abstract The article gives an overview of phytic acid in food and of its significance for human nutrition. It summarises phytate sources in foods and discusses problems of phytic acid/phytate contents of food tables. Data on phytic acid intake are evaluated and daily phytic acid intake depending on food habits is assessed. Degradation of phytate during gastro-intestinal passage is summarised, the mechanism of phytate interacting with minerals and trace elements in the gastro-intestinal chyme described and the pathway of inositol phosphate hydrolysis in the gut presented. The present knowledge of phytate absorption is summarised and discussed. Effects of phytate on mineral and trace element bioavailability are reported and phytate degradation during processing and storage is described. Beneficial activities of dietary phytate such as its effects on calcification and kidney stone formation and on lowering blood glucose and lipids are reported. The antioxidative property of phytic acid and its potentional anticancerogenic activities are briefly surveyed. Development of the analysis of phytic acid and other inositol phosphates is described, problems of inositol phosphate determination and detection discussed and the need for standardisation of phytic acid analysis in foods argued. [source] Nutritional evaluation of some Nigerian wild seedsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 2 2004Ganiyu Oboh Abstract Some wild seeds, namely Parkia biglobosa, Tetracarpidum conophorum, Pentaclethra macrophylla, Irvingia gabonensis, Afzelia africana, Prosporis africana and Monodora myristica, were randomly collected from various parts of Nigeria and analyzed with regard to their proximate, mineral, antinutrient composition and zinc bioavailability. The results revealed that the seeds had high protein (6.5,24.2%), fat (19.0,58.5%), mineral (Mg, Fe, Zn, Mn, Ca, Na, K, P) and phytate (1043.6,2905.2 mg/100 g) contents, while the cyanide content was low (3.7,6.4 mg/kg). However, Co, Pb and Ni were not detected in all the samples. The calculated [Ca] [phytate]/[Zn] molar ratios (which is the best index for predicting Zn bioavailability) for all the seeds revealed that Parkia biglobosa, Irvingia gabonensis and Prosporis africana had a calculated molar ratio above 0.50 mol/kg (critical level), thus indicating reduced bioavailability of Zn to a critical level. In view of the high fat, protein, mineral and low cyanide contents, the high phytate content would not be expected to reduce bioavailability of Zn in some of the wild seeds (Afzelia africana, Pentaclethra macrophylla and Monodora myristica). These wild seeds could be good nutrient sources if integrated fully into human and animal nutrition. However, further studies will be carried out on the protein quality and toxicological potentials of these wild seeds. [source] In vitro availability of minerals of some tropical and citrus fruits as influenced by antinutritional factorsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 1 2004Inass O. Malik Abstract Four tropical fruits and three citrus fruits were analyzed for moisture, ash, antinutritional factors (phytate, oxalate, and polyphenols) contents, and total and available minerals. Moisture contents ranged from 6.0 to 83.17% for tropical fruits while that of citrus fruits ranged from 88.20 to 89.50%. Ash contents ranged from 2.56 to 4.50% and from 3.83 to 4.83%, for tropical and citrus fruits, respectively. All fruits contained no oxalate while phytate and polyphenols ranged from 48.1 to 134.1 mg/100 g and from 0.115 to 0.34%, respectively. For all fruits major minerals contents ranged from 7.7 to 433.3 while trace ones ranged from 0.116 to 1.91 mg/100 g. In vitro availabilities of major minerals (% of total) varied from 11.1 to 86.2% while for minor ones it ranged from 13 to 72.5%. [source] Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) multiple inositol polyphosphate phosphatases (MINPPs) are phytases expressed during grain filling and germination,PLANT BIOTECHNOLOGY JOURNAL, Issue 2 2007Giuseppe Dionisio Summary At present, little is known about the phytases of plant seeds in spite of the fact that this group of enzymes is the primary determinant for the utilization of the major phosphate storage compound in seeds, phytic acid. We report the cloning and characterization of complementary DNAs (cDNAs) encoding one of the groups of enzymes with phytase activity, the multiple inositol phosphate phosphatases (MINPPs). Four wheat cDNAs (TaPhyIIa1, TaPhyIIa2, TaPhyIIb and TaPhyIIc) and three barley cDNAs (HvPhyIIa1, HvPhyIIa2 and HvPhyIIb) were isolated. The open reading frames ranged from 1548 to 1554 bp and the level of homology between the barley and wheat proteins ranged from 90.5% to 91.9%. All cDNAs contained an N-terminal signal peptide encoding sequence, and a KDEL-like sequence, KTEL, was present at the C-terminal, indicating that the enzyme was targeted to and retained within the endoplasmic reticulum. Expression of TaPhyIIa2 and HvPhyIIb in Escherichia coli revealed that the MINPPs possessed a significant phytase activity with narrow substrate specificity for phytate. The pH and temperature optima for both enzymes were pH 4.5 and 65 °C, respectively, and the Km values for phytate were 246 and 334 µm for the wheat and barley recombinant enzymes, respectively. The enzymes were inhibited by several metal ions, in particular copper and zinc. The cDNAs showed significantly different temporal and tissue-specific expression patterns during seed development and germination. With the exception of TaPhyIIb, the cDNAs were present during late seed development and germination. We conclude that MINPPs constitute a significant part of the endogenous phytase potential of the developing and germinating barley and wheat seeds. [source] Growth of the vacuoleless mutant of Tetrahymena thermophila NP1 in phytateTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2005SAMANTHA WEBB Phytate, the salt form of phytic acid, is the major store of phosphate in seeds and grain. Since non-ruminant farm animals poorly digest phytate, it is also a source of environmental phosphate contamination in agricultural areas. We are using Tetrahymena, a ciliated protist with multiple routes for nutrient assimilation, as a model to investigate the contribution of heterotrophic protists to the environmental cycling of phosphate from phytate. This ciliate has the ability to grow on phytate as the sole phosphate source (Ziemkiewicz, H. T., Johnson, M. D. & Smith-Somerville, H. E. 2002. J. Eukaryot. Microbiol., 49:428). Tetrahymena thermophila NP1, a temperature-sensitive vacuoleless mutant (ATCC #50202), provides a way to separate membrane transport from uptake through phagosomes, and to assess the importance of each mechanism. This cell grows equally well at the permissive and non-permissive temperatures with either phytate or inorganic phosphate as the phosphate source. Our results demonstrate that phagosomes are not required to use the phosphate from phytate. [source] Effect of phytate-removal and deamidation of soybean proteins on calcium absorption in the in situ ratsBIOFACTORS, Issue 1-4 2004Hitomi Kumagai Abstract Soybean proteins were deamidated by cation-exchange resins after phytate, the inhibitor for calcium absorption from the small intestine, was removed in order to provide the enhancement function of calcium absorption to soybean proteins. About 92% of the phosphorus was removed from the soybean proteins by anion-exchange-resin treatment, indicating that most of the phytate was removed. About 70% of the acid amide was deamidated by cation-exchange-resin treatment, and phytate-removed and deamidated soybean proteins (PrDS) having high calcium binding properties were obtained. PrDS were hydrolyzed by digestive enzymes and their calcium-binding properties and the enhancement function of the calcium absorption from the small intestine of rats were examined. As a result, PrDS retained their high calcium binding properties even after hydrolysis by digestive enzymes. in situ experiments showed that PrDS and their hydrolysates enhanced the calcium absorption from the intestine. [source] | ||||||||||||||||