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Phytate Content (phytate + content)
Selected AbstractsPhytate 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] The effect of roasting on the nutritional and antioxidant properties of yellow and white maize varietiesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2010Ganiyu Oboh Summary Maize varieties (yellow and white) were roasted for 17 min; and allowed to cool, and later milled into powder. The nutritional evaluation (proximate composition, mineral and antinutrient content determination) and antioxidant properties investigation (reducing power, free radicals scavenging ability and Fe2+ chelating ability) of the product was subsequently carried out. The result of the study revealed that roasting caused a significant increase (P < 0.05) in the crude fat, carbohydrate, Ca, Na, Mg and Zn content. Conversely, a significant decrease (P < 0.05) was observed in crude protein, crude fibre, Fe and K content. A significant decrease in the phytate content was also observed. However, the reduced phytate content did not have sparing effect on Zn bioavailability. Roasting significantly (P < 0.05) reduced the extractible phenol and flavonoid content of the maize varieties. The antioxidant properties (1,1-diphenyl-2-picrylhydracyl free radical scavenging ability and Fe2+ chelating ability) followed the phenolic content pattern. However, roasting caused a significant increase in the ferric reducing antioxidant power of the maize varieties. Thus, roasting reduced the protein content of maize but also increased the energy value and antioxidant capacity as exemplified by high reducing power. [source] Characterisation of soybean glycinin and ,-conglycinin fractionated by using MgCl2 instead of CaCl2INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2010Chong Liu Summary A simple two step precipitation method was used to investigate the effect of MgCl2 instead of CaCl2 on fractionation of soybean glycinin and ,-conglycinin. Compositional and physicochemical properties of the resulting protein fractions were characterised. The optimised procedure, in terms of protein yield, purity, phytate content and physicochemical properties, was obtained when the addition of 5 mm MgCl2 was used. After application of 5 mm MgCl2, the phytate content of the glycinin-rich and ,-conglycinin-rich fractions was about 0.4% and 1.3%, respectively, but the addition of 5 mm CaCl2 increased the phytate content of the glycinin-rich fraction to 1.25% and decreased that of ,-conglycinin-rich fraction to 0.67%. Low phytate protein product was suitable for use in infant formula and acidic food. The solubility of the glycinin-rich fractions with MgCl2 was significantly higher than that with CaCl2 at pH < 4.5. Application of MgCl2 improved thermal stability of the ,-conglycinin-rich fraction. [source] The effect of drying conditions on the development of the hard-to-cook defect in steam-treated cowpeasINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2006Nicole S. Affrifah Summary A three-factor,three-level Box,Behnken design was used to evaluate the effect of drying time, temperature and humidity on textural and physicochemical characteristics during storage of steamed cowpeas. The treatment significantly improved cooked texture and prevented hardening during storage under severe conditions (42 °C/80% relative humidity, RH). Before storage, the cooked texture of treated samples was between 535,628 and 602 N for the untreated control, and between 516,649 and 1394 N after storage at 42 °C/80% RH. The peak force of stored cowpeas significantly decreased as the drying temperature increased. Steaming and drying reduced phytase activity to 59,64% of the original activity and decreased phytate content from 0.133% to 0.074,0.105%. Drying time had a significant effect on phytase activity whereas all drying parameters significantly affected phytate concentration and water absorption. The drying conditions applied after steaming significantly influences seed characteristics; therefore, selection of optimum drying conditions may be used to control seed quality, especially texture. [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] EFFECTS OF WATER STRESS ON THE PROXIMATE COMPOSITION AND MINERAL CONTENTS OF SEEDS OF TWO LUPINS (LUPINUS ALBUS AND LUPINUS MUTABILIS)JOURNAL OF FOOD QUALITY, Issue 4 2005ISABEL MARIA MARQUES SARAIVA DE CARVALHO ABSTRACT Because mineral composition data for lupins subjected to water stress (ws) are incomplete, it is essential to analyze those seeds in order to assess the quality of potential food source for both human and animal nutrition. So, we have performed chemical proximate analysis and determined the mineral profile of seeds from two lupins subjected to ws period and compared with seeds from well-watered (ww) plants. From the above results we can conclude that the values obtained fall within the range of values reported for both species (at ww conditions) and no significant (P > 0.05) differences were found in nutritional composition and mineral content between both lupins. Ws period was responsible for a significant increase in sugar, ash, both macroelements (Ca, Na, K, Mg) and microelements (Fe, Zn, Mn, Cu) as well as phytate content. The results obtained are relevant for selection of better mineral nutritive value of seeds from lupin species. [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] 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] 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] 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] | ||||||||||