Home About us Contact
|
Home About us Contact | ||
|
|
||
Phytic Acid (phytic + acid)
Terms modified by Phytic Acid Selected AbstractsStable Amorphous CaCO3 Microparticles with Hollow Spherical Superstructures Stabilized by Phytic Acid,ADVANCED MATERIALS, Issue 18 2005A.-W. Xu Amorphous CaCO3 (ACC) is stabilized by the presence of phytic acid, a natural inositol hexakisphosphate (IP6). Micrometer-sized hollow spheres of ACC have been obtained (see Figure). The spheres are stable for at least three months in solution, which is equivalent to that described for more complex special biopolymers in biomineralization processes, and by far exceeds the previously known stability of ACC prepared in the presence of synthetic molecules. [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] 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] Generation of stable ,low phytic acid' transgenic rice through antisense repression of the 1d - myo -inositol 3-phosphate synthase gene (RINO1) using the 18-kDa oleosin promoterPLANT BIOTECHNOLOGY JOURNAL, Issue 1 2009Mio Kuwano Summary Phytic acid acts as the major storage form of phosphorus in plant seeds and is poorly digested by monogastric animals. The degradation of phytic acid in animal diets is necessary to overcome both environmental and nutritional issues. The enzyme 1d - myo -inositol 3-phosphate [Ins(3)P1] synthase (EC 5.5.1.4) catalyses the first step of myo -inositol biosynthesis and directs phytic acid biosynthesis in seeds. The rice Ins(3)P1 synthase gene (RINO1) is highly expressed in developing seed embryos and in the aleurone layer, where phytic acid is synthesized and stored. In rice seeds, 18-kDa oleosin (Ole18) is expressed in a seed-specific manner, and its transcripts are restricted to the embryo and the aleurone layer. Therefore, to effectively suppress phytic acid biosynthesis, antisense RINO1 cDNA was expressed under the control of the Ole18 promoter, directing the same spatial pattern in seeds as RINO1 in transgenic rice plants. The generated transgenic rice plants showed strong ,low phytic acid' (lpa) phenotypes, in which seed phytic acid was reduced by 68% and free available phosphate was concomitantly increased. No negative effects on seed weight, germination or plant growth were observed. The available phosphate levels of the stable transgenic plants surpassed those of currently available rice lpa mutants. [source] Characterization of the MIPS gene family in Glycine maxPLANT BREEDING, Issue 5 2006A. S. Chappell Abstract Phytic acid (myo -inositol-1,2,3,4,5,6-hexakisphosphate) is the primary storage component of phosphorus in plant seeds. The first step in phytic acid biosynthesis is the de novo synthesis of myo -inositol, which is catalyzed by the enzyme D -myo -inositol 3-phosphate synthase (MIPS EC 5.5.1.4). Previous work detected four MIPS genes in soybean (Glycine max). However, only a limited amount of data were available for the MIPS gene family and some of the data were conflicting. The work described here clears up these data and characterizes the MIPS gene family for the purposes of reverse genetic technologies. The complete genomic sequence of all four genes was determined and their expression profile was examined by quantitative real-time reverse transcription-polymerase chain reaction. Our results indicate that the four MIPS genes are highly conserved and temporally and spatially expressed. The MIPS gene family in the low phytic acid soybean line, CX1834, was also characterized since this line displays a phenotype similar to previously characterized MIPS mutants. These data demonstrate that mutations in MIPS genes are not the cause of the low phytic acid phenotype. [source] Phytase activity in Cryptococcus laurentii ABO 510FEMS YEAST RESEARCH, Issue 3 2007Jason Van Staden Abstract Ten Cryptococcus strains were screened for phytase activity, of which the Cryptococcus laurentii ABO 510 strain showed the highest level of activity. The cell wall-associated enzyme displayed temperature and pH optima of 62°C and 5.0, respectively. The enzyme was thermostable at 70°C, with a loss of 40% of its original activity after 3 h. The enzyme was active on a broad range of substrates, including ATP, d -glucose 6-phosphate, d -fructose 1,6-diphosphate and p -nitrophenyl phosphate (p -NPP), but its preferred substrate was phytic acid (Km of 21 ,M). The enzyme activity was completely inhibited by 0.5 mM inorganic phosphate or 5 mM phytic acid, and moderately inhibited in the presence of Hg2+, Zn2+, Cd2+ and Ca2+. These characteristics suggest that the Cry. laurentii ABO 510 phytase may be considered for application as an animal feed additive to assist in the hydrolysis of phytate complexes to improve the bioavailability of phosphorus in plant feedstuff. [source] Stable Amorphous CaCO3 Microparticles with Hollow Spherical Superstructures Stabilized by Phytic Acid,ADVANCED MATERIALS, Issue 18 2005A.-W. Xu Amorphous CaCO3 (ACC) is stabilized by the presence of phytic acid, a natural inositol hexakisphosphate (IP6). Micrometer-sized hollow spheres of ACC have been obtained (see Figure). The spheres are stable for at least three months in solution, which is equivalent to that described for more complex special biopolymers in biomineralization processes, and by far exceeds the previously known stability of ACC prepared in the presence of synthetic molecules. [source] Effect of different chemical compounds as coadjutants of 4-hexylresorcinol on the appearance of deepwater pink shrimp (Parapenaeus longirostris) during chilled storageINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 11 2008Oscar Martínez-Alvarez Summary Different chemical compounds (kojic acid, cumic acid, phytic acid, sodium metabisulphite, magnesium carbonate, sorbic acid and different protease inhibitors) were used as coadjutants in 4-hexylresorcinol (4-HR)-based melanosis-inhibiting formulas tested for inhibiting melanosis in pink shrimp (Parapenaeus longirostris). The experiment was performed on board ship. Increasing concentrations of 4-HR delayed the occurrence of melanosis during storage. However, 4-HR could not prevent the appearance of a yellow-greenish colouration in the cephalothorax that diminishes the consumer acceptability of shrimps. The incorporation of protease inhibitors (ethylenediaminetetraacetic acid, disodium dihydrogen pyrophosphate, iodoacetic acid, egg white and phenylmethylsulphonyl fluoride) into the 4-HR-based mixtures improved the acceptability after storage, suggesting that protease activity post-mortem contributes to the reduction in the final acceptability of crustaceans. [source] Minerals and phytic acid interactions: is it a real problem for human nutrition?INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2002H. Walter Lopez Summary Because of its high density of negatively charged phosphate groups, phytic acid (PA) forms very stable complexes with mineral ions rendering them unavailable for intestinal uptake. Indeed, the first step in mineral absorption requires that the mineral remains in the ionic state. As the PA content of the diet increases, the intestinal absorption of zinc, iron and calcium decreases. The inhibitory effects of PA on magnesium or copper are more controversial. Nevertheless, PA does not occur alone in foods and is often consumed with various compounds. Phytates are always present in vegetal matrix composed of fibres, minerals, trace elements and other phytomicronutrients. Thus, in order to evaluate mineral absorption from phytate-rich products, all components of diet and food interactions should be considered and it is hard to predict mineral bioavailability in such products by using only the phytate content. [source] Phytate 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] Nutritional evaluation of fermented black gram (Phaseolus mungo) seed meal in compound diets for rohu, Labeo rohita (Hamilton), fingerlingsJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2007S. Ramachandran Summary Six isonitrogenous (approximately 35% crude protein) and isocaloric (approximately 4.0 kcal g,1) diets were formulated incorporating raw and fermented black gram, Phaseolus mungo, seed meal at 20%, 30% and 40% levels by weight into a fishmeal-based control diet fed to rohu, Labeo rohita, fingerlings (mean weight, 1.81 ± 0.21 g) for 80 days for a study of fish performance. A particular bacterial strain (Bacillus sp.) isolated from the intestine of adult common carp (Cyprinus carpio) reared in the wild having significant amylolytic, cellulolytic, lipolytic and proteolytic activities was used for fermentation of seed meal for 15 days at 37 ± 2°C. Fermentation of P. mungo seed meal was effective in significantly reducing the crude fibre content and antinutritional factors such as tannins and phytic acid, and enhancing available free amino acids and fatty acids. In terms of growth, feed conversion ratio and protein efficiency ratio, the 30% fermented black gram seed meal incorporated diet resulted in a significantly (P < 0.05) better performance of rohu fingerlings. In general, growth and feed utilization efficiencies of diets containing fermented seed meal were superior to diets containing raw seed meal. The apparent protein digestibility (APD) values decreased with increasing levels of raw seed meal in the diets. The APD for raw seed meal was lower at all levels of inclusion in comparison to those for the fermented seed meals. The maximum deposition of protein in the carcass was recorded in fish fed the diet containing 40% fermented seed meal. The results indicate that fermented black gram seed meal can be incorporated in carp diets up to the 30% level compared to the 10% level of raw seed meal. [source] Phytase production by Sporotrichum thermophile in a cost-effective cane molasses medium in submerged fermentation and its application in breadJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008B. Singh Abstract Aims:, Phytase production by Sporotrichum thermophile in a cost-effective cane molasses medium in submerged fermentation and its application in bread. Methods and Results:, The production of phytase by a thermophilic mould S. thermophile was investigated using free and immobilized conidiospores in cane molasses medium in shake flasks, and stirred tank and air-lift fermenters. Among surfactants tested, Tweens (Tween-20, 40 and 80) and sodium oleate increased phytase accumulation, whereas SDS and Triton X-100 inhibited the enzyme production. The mould produced phytase optimally at aw 0·95, and it declined sharply below this aw value. The enzyme production was comparable in air-lift and stirred tank reactors with a marked reduction in fermentation time. Among the matrices tried, Ca-alginate was the best for conidiospore immobilization, and fungus secreted sustained levels of enzyme titres over five cycles. The phytic acid in the dough was efficiently hydrolysed by the enzyme accompanied by the liberation of soluble phosphate in the bread. Conclusions:, The phytase production by S. thermophile was enhanced in the presence of Tween-80 in cane molasses medium. A peak in enzyme production was attained in 48 h in the fermenter when compared with that of 96 h in shake flasks. Ca-alginate immobilized conidiospores germinated to produce fungal growth that secreted sustained levels of phytase over five cycles. The bread made with phytase contained reduced level of phytic acid and a high-soluble phosphate. Significance and Impact of the Study:, The phytase accumulation by S. thermophile was increased by the surfactants. The sustainability of enzyme production in stirred tank and air-lift fermenters suggested the possibility for scaling up of phytase. The bread made with phytase contained low level of antinutrient, i.e. phytic acid. [source] Mild zinc deficiency and dietary phytic acid accelerates the development of fulminant hepatitis in LEC ratsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2 2007Akiko Saito Abstract Background and Aim:, Restriction of copper intake delays hepatic copper accumulation in Long,Evans Cinnamon (LEC) rats, which are animal models of Wilson's disease. Involvement of zinc is suggested to develop hepatitis in the disease; however, this has not been clarified. The aims of this study were to investigate the effects of mild zinc deficiency on the development of hepatitis and to determine the relationship between the absorption and hepatic levels of copper, zinc and iron. Methods:, Male LEC and F344 (wild type atp7b) rats were fed a low zinc, phytate-containing or control diet. The onset of hepatitis (Experiment 1), and absorptive rates of copper, zinc and iron and hepatitis indices in 4 weeks (Experiment 2) were observed. Results:, The onset of fulminant hepatitis in LEC rats was much earlier in the low zinc and phytate groups (mean 94.6 ± 2.74 days and 82.8 ± 3.56 days old, respectively) than in the control group (136 ± 2.11 days old) with worse hepatitis indices. Hepatic copper levels were much higher in LEC rats than F344 rats, but were not largely different among the diet groups without prominent changes in copper absorption. Hepatic levels and intestinal absorption of zinc and iron were lower in the phytate group than in the control group. Conclusion:, Mild zinc deficiencies caused by a low zinc or phytate-containing diet accelerate the onset of hepatitis in LEC rats without increasing copper absorption, and zinc and iron metabolism may be involved in the earlier onset of jaundice of LEC rats. [source] Zinc bioavailability in wheat grain in relation to phosphorus fertiliser, crop sequence and mycorrhizal fungiJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008Megan H Ryan Abstract BACKGROUND: While human diets are often deficient in zinc (Zn), the impacts of crop management on Zn in cereal grains are rarely examined. In this study the effect of phosphorus (P) fertiliser and crop sequence (wheat following canola, linola, fallow or pasture) on wheat grain Zn concentration and bioavailability for humans was investigated. RESULTS: The Zn concentration of wheat grain decreased by 33,39% in response to P fertiliser. It was also 30,40% lower for crops following canola and fallow than for those following linola and pasture. P fertiliser decreased the colonisation of arbuscular mycorrhizal fungi (AMF) in wheat roots, and canola and fallow led to lower colonisation than linola and pasture. Since AMF are known to assist in soil uptake of immobile nutrients such as Zn, it is hypothesised that P fertiliser and crop sequence affected grain Zn concentration through AMF. P fertiliser also increased the concentrations of grain P by 17% and grain phytic acid (PA) by 19%, but had little effect on the concentrations of calcium (Ca), iron (Fe) and polyphenols. Other impacts of crop sequence were slightly higher concentrations in grain of P after pasture and Fe after canola. The bioavailability of grain Zn, as shown by the PA:Zn and Ca × PA:Zn molar ratios, mostly reflected Zn concentration and was low in all treatments. After milling, the PA:Zn molar ratio suggested low Zn bioavailability for flour from wheat grown with P fertiliser after canola or fallow. CONCLUSION: Crop management can affect the bioavailability of Zn in wheat grain, with practices leading to high yields potentially leading to low Zn bioavailability. Copyright © 2008 Society of Chemical Industry [source] In vitro bioavailability of calcium and iron from selected green leafy vegetables,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2006Sheetal Gupta Abstract The objective of the present investigation was to analyze the relative influence of oxalic acid, phytic acid, tannin and dietary fiber on in vitro availability of iron and calcium from green leafy vegetables (GLV). Thirteen GLV were selected and analyzed for iron, calcium, oxalic acid, phytic acid, tannin and dietary fiber contents using standard methods. The bioavailability of calcium and iron in the GLV was estimated by equilibrium dialysis. Oxalic acid content was less than 1 g kg,1 in four greens and ranged between 1.22 to 11.98 g kg,1 in the remaining. Dietary fiber ranged from 19.5 to 113.7 g kg,1. Tannin content ranged between 0.6138 and 2.1159 g kg,1 with the exception of two GLV that had 0.1332 and 14.8619 g kg,1. Four GLV were found to have approximately 40% bioavailable iron, while the others were in the range of 6,30%. In vitro available calcium was less than or equal to 25% in eight GLV and between 34% and 52% in five GLV. Multiple regression analysis revealed that these factors together accounted for 53% (r2 = 0.53) and 45% (r2 = 0.45) inhibition of iron and calcium absorption, respectively. These findings infer that calcium and iron availability is influenced by the constituents present in the GLV. Copyright © 2006 Society of Chemical Industry [source] Utilization of protein concentrates from ungerminated and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds in cookie formulationsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2004SY Giami Abstract Cookies (soft type biscuits) were produced from blends of wheat flour containing graded levels (0,25%) of protein concentrates prepared from ungerminated and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds and evaluated for nutritional, baking and sensory properties. Protein quality was investigated using weanling albino rats fed diets that were formulated to supply 10% protein using cookie samples, with casein as a control. Cookies produced from blends containing protein concentrates from germinated seeds had higher contents of crude protein and lower levels of polyphenol and phytic acid, compared with cookies supplemented with concentrates from ungerminated seeds. The use of up to 15% concentrate from ungerminated seeds in the blends produced cookies with spread ratio, hardness, colour and flavour similar to the 100% wheat flour (control) cookies. Cookies supplemented with concentrates from germinated seeds at 15,25% levels were nutritionally comparable to diets based on casein, but at the expense of acceptability. Copyright © 2004 Society of Chemical Industry [source] Dephytinisation of rice bran and manufacturing a new food ingredientJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2001Wea-Shang Fuh Abstract Rice bran was extruded at 130,°C and a screw speed of 140,rpm for 20,s to inactivate lipase and prevent lipid oxidation. Although the extrusion process induced further complex formation between phytic acid and protein as well as between phytic acid and starch, nearly 94% of phytic acid in the extruded rice bran could still be removed by solid/liquid extraction conducted at 25,°C for 30,min using hydrochloric acid at pH 2 as solvent and a solvent/rice bran ratio of 15. After the extract had been neutralised and phytic acid removed, it was added back to the rice bran solid to replenish the nutritional and functional components of the solid. The mixture was then dried in a drum dryer to yield a powdered product. The dephytinised rice bran product contained most of the protein, fat, dietary fibre and B vitamins and more than 50% of the oryzanol originally present in the raw rice bran. © 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] Generation of stable ,low phytic acid' transgenic rice through antisense repression of the 1d - myo -inositol 3-phosphate synthase gene (RINO1) using the 18-kDa oleosin promoterPLANT BIOTECHNOLOGY JOURNAL, Issue 1 2009Mio Kuwano Summary Phytic acid acts as the major storage form of phosphorus in plant seeds and is poorly digested by monogastric animals. The degradation of phytic acid in animal diets is necessary to overcome both environmental and nutritional issues. The enzyme 1d - myo -inositol 3-phosphate [Ins(3)P1] synthase (EC 5.5.1.4) catalyses the first step of myo -inositol biosynthesis and directs phytic acid biosynthesis in seeds. The rice Ins(3)P1 synthase gene (RINO1) is highly expressed in developing seed embryos and in the aleurone layer, where phytic acid is synthesized and stored. In rice seeds, 18-kDa oleosin (Ole18) is expressed in a seed-specific manner, and its transcripts are restricted to the embryo and the aleurone layer. Therefore, to effectively suppress phytic acid biosynthesis, antisense RINO1 cDNA was expressed under the control of the Ole18 promoter, directing the same spatial pattern in seeds as RINO1 in transgenic rice plants. The generated transgenic rice plants showed strong ,low phytic acid' (lpa) phenotypes, in which seed phytic acid was reduced by 68% and free available phosphate was concomitantly increased. No negative effects on seed weight, germination or plant growth were observed. The available phosphate levels of the stable transgenic plants surpassed those of currently available rice lpa mutants. [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] Apparent digestibility of nutrients and energy in extruded diets from cultivars of barley and wheat selected for nutritional quality in rainbow trout Oncorhynchus mykissAQUACULTURE NUTRITION, Issue 3 2009T.G. GAYLORD Abstract A digestibility trial was conducted to elucidate potential differences in barley (Hordeum vulgare L.) lines and varieties as a first step in defining their potential for use in aquafeeds. A diverse group of six barley lines having six combinations of selected attributes, normal versus low phytic acid, normal versus waxy, and hulled versus hull-less, were chosen for evaluation along with a waxy wheat (Triticum aestivum L.) and soft white wheat. The experimental diets were manufactured by cooking extrusion and consisted of a 70% reference diet that was formulated to contain a minimal level of phosphorus and 30% test ingredient. Phosphorus availability ranged from 17 to 78% and was influenced by starch type in wheat. Apparent protein digestibility ranged from 53 to 125% and differences were observed between wheat varieties based on starch type. Apparent energy digestibility ranged from 32 to 63%, with waxy barley varieties having higher energy digestibility coefficients than normal starch varieties. Waxy starch varieties had higher starch digestibility in both barley and wheat because of the greater digestibility of amylopectin than amylose. In summary, the higher energy digestibility of waxy barley lines suggests that these varieties warrant further attention as feed ingredients for rainbow trout. [source] A phytase enzyme-based biochemistry practical particularly suited to students undertaking courses in biotechnology and environmental scienceBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 5 2004Angela Boyce Abstract Courses in introductory biochemistry invariably encompass basic principles of enzymology, with reinforcement of lecture-based material in appropriate laboratory practicals. Students undertaking practical classes are more enthusiastic, and generally display improved performance, when the specific experiments undertaken show direct relevance to their core degree area. Herein is described an enzyme-based practical of particular relevance to students undertaking primary degrees in biotechnology, environmental science, nutrition, as well as animal and veterinary science. The practical entails assay of phytase, an enzyme that is now routinely included in monogastric animal feed in order to ameliorate the negative nutritional and environmental consequences of its substrate, dietary phytic acid. The practical is technically straightforward, requiring relatively basic laboratory equipment and reagents that are both easily obtained and relatively inexpensive. To be an effective digestive supplement, the enzyme must display a combination of physicochemical properties, which provide sufficient scope for an interesting and multifaceted post-laboratory discussion. [source] Treatment of Germinated Wheat to Increase Levels of GABA and IP6 Catalyzed by Endogenous EnzymesBIOTECHNOLOGY PROGRESS, Issue 2 2005Hiroyuki Nagaoka We found that the levels of bioactive products from wheat can be increased dramatically by manipulating germination conditions and taking advantage of the activity of endogenous enzymes. The yield of phytic acid (IP6) from wheat germinated in the presence of high, controlled levels of dissolved oxygen (188 ± 28 mg/100 g wheat) was almost three times greater than that from wheat germinated with no supplemental oxygen (74 ± 10 mg/100 g wheat). The yield of ,-aminobutyric acid (GABA) from wheat germinated in the presence of uncontrolled levels of dissolved oxygen was 18 ± 3 times greater than that from nonsupplemented wheat (1 mg/100 g wheat). The concentration of GABA was much greater in wheat germ than in whole wheat, and the yield of GABA from wheat germ processed with supplemental water (163 ± 7 mg/100 g wheat germ) was notably greater than that from wheat germ processed with no supplemental water (100 ± 2 mg/100 g wheat germ). In contrast, IP6 was more concentrated in wheat bran, and the yield of IP6 from wheat bran processed with supplemental water (3100 ± 12 mg/100 g wheat bran) was notably higher than that from wheat bran processed with no supplemental water (2420 ± 13 mg/100 g wheat bran). We conclude that the large amount of GABA extracted from wheat germ is likely due to high glutamate decarboxylase activity and low aminotransferase activity and that the large amount of IP6 extracted from wheat bran is likely due to high levels of tyrosinase activity. Our findings indicate that bioactive molecules such as GABA and IP6 can be successfully mass-produced by taking advantage of endogenous enzymatic activities. [source] hytic Acid Conversion Coatings of MagnesiumCHINESE JOURNAL OF CHEMISTRY, Issue 4 2010Jianrui Liu Abstract A chrome-free conversion coating treatment for magnesium by phytic acid solution was developed. The immersion experiments were used for evaluating the effects of the processing parameters (such as conversion temperature and time, concentration and pH value of phytic acid solution) on the corrosion resistance of the phytic acid conversion coating. The morphologies and compositions of the coatings were determined by SEM and EDS respectively. The experimental results indicated that the corrosion resistance of the conversion coating formed in the solution containing 0.5% phytic acid at 25°C and pH=4 for 30 min was higher than that of natural oxide, and the conversion coating formed on the surface of magnesium was of multilayer mainly consisting of Mg, C, O and P. The thicknesses of the conversion coatings were approximately 1.0,15 µm and the conversion coatings presented obvious network-like cracks. The electrochemical potentiodynamic polarization experiment indicated that the free corrosion potential of the magnesium with phytic acid conversion coating was increased, and its corrosion current and corrosion rate declined in 3.5% NaCl solution. Phytic acid conversion coating could improve the electrochemical property of magnesium and provide effective protection, which can improve the corrosion resistance of magnesium. [source] Generation of stable ,low phytic acid' transgenic rice through antisense repression of the 1d - myo -inositol 3-phosphate synthase gene (RINO1) using the 18-kDa oleosin promoterPLANT BIOTECHNOLOGY JOURNAL, Issue 1 2009Mio Kuwano Summary Phytic acid acts as the major storage form of phosphorus in plant seeds and is poorly digested by monogastric animals. The degradation of phytic acid in animal diets is necessary to overcome both environmental and nutritional issues. The enzyme 1d - myo -inositol 3-phosphate [Ins(3)P1] synthase (EC 5.5.1.4) catalyses the first step of myo -inositol biosynthesis and directs phytic acid biosynthesis in seeds. The rice Ins(3)P1 synthase gene (RINO1) is highly expressed in developing seed embryos and in the aleurone layer, where phytic acid is synthesized and stored. In rice seeds, 18-kDa oleosin (Ole18) is expressed in a seed-specific manner, and its transcripts are restricted to the embryo and the aleurone layer. Therefore, to effectively suppress phytic acid biosynthesis, antisense RINO1 cDNA was expressed under the control of the Ole18 promoter, directing the same spatial pattern in seeds as RINO1 in transgenic rice plants. The generated transgenic rice plants showed strong ,low phytic acid' (lpa) phenotypes, in which seed phytic acid was reduced by 68% and free available phosphate was concomitantly increased. No negative effects on seed weight, germination or plant growth were observed. The available phosphate levels of the stable transgenic plants surpassed those of currently available rice lpa mutants. [source] | |||||||||||||||||||