The degradation of phytate by microbial and wheat phytases is dependent on the phytate matrix and the phytase origin

BACKGROUND: Phytases increase utilization of phytate phosphorus in feed. Since wheat is rich in endogenous phytase activity it was examined whether wheat phytases could improve phytate degradation compared to microbial phytases. Moreover, it was investigated whether enzymatic degradation of phytate is influenced by the matrix surrounding it. Phytate degradation was defined as the decrease in the sum of InsP₆ + InsP₅. RESULTS: Endogenous wheat phytase effectively degraded wheat InsP₆ + InsP₅ at pH 4 and pH 5, while this was not true for a recombinant wheat phytase or phytase extracted from wheat bran. Only microbial phytases were able to degrade InsP₆ + InsP₅ in the entire pH range from 3 to 5, which is relevant for feed applications. A microbial phytase was efficient towards InsP₆ + InsP₅ in different phytate samples, whereas the ability to degrade InsP₆ + InsP₅ in the different phytate samples ranged from 12% to 70% for the recombinant wheat phytase. CONCLUSION: Wheat phytase appeared to have an interesting potential. However, the wheat phytases studied could not improve phytate degradation compared to microbial phytases. The ability to degrade phytate in different phytate samples varied greatly for some phytases, indicating that phytase efficacy may be affected by the phytate matrix. Copyright © 2011 Society of Chemical Industry     

Analysis of isoflavone content in tempeh, a fermented soybean, and preparation of a new isoflavone-enriched tempeh

To produce a tempeh-like functional food containing a high level of isoflavone with a high absorptivity, we analyzed changes in the composition of isoflavone during tempeh fermentation and the difference in isoflavone content depending on the soybean variety and particular tissue. By adding soybean germ (hypocotyl) that contained a large amount of isoflavone, we prepared a new isoflavone-enriched tempeh in the form of a granular fermented soybean-based food, which can serve as a nutritious supplement for the elderly.     

Dietary roles of phytate and phytase in human nutrition: A review

Phytate is the primary storage form of both phosphate and inositol in plant seeds. It forms complexes with dietary minerals, especially iron and zinc, and causes mineral-related deficiency in humans. It also negatively impacts protein and lipid utilisation. It is of major concern for individuals who depend mainly on plant derivative foods. Processing techniques, such as soaking, germination, malting and fermentation, reduce phytate content by increasing activity of naturally present phytase. Supplementation of phytase in diets results in increase in mineral absorption. Apart from negative effects, its consumption provides protection against a variety of cancers mediated through antioxidation properties, interruption of cellular signal transduction, cell cycle inhibition and enhancement of natural killer (NK) cells activity. It has therapeutic use against diabetes mellitus, atherosclerosis and coronary heart disease and reduces kidney stone formation, HIV-1 and heavy metal toxicity; however, information on the dosage for humans for eliciting beneficial effects is limited.     

Dominant Enterobacteriaceae in tempeh were primarily originated from soybean

Food Science and Biotechnology - During tempeh production, boiling was considered as heat treatment that could significantly reduce or eliminate bacterial population in soybean before fungal...     

不同发芽条件对大麦中植酸含量及植酸酶活力的影响

大麦发芽过程中,发芽温度、浸麦水pH值及浸麦水中金属离子的种类和含量是影响大麦中植酸含量及植酸酶活力的重要因素。实验发现,当发芽温度为16℃时,植酸酶较高温和低温发芽更早的被激活,其活力达到4.032 8U/g(绝干),更加有利于植酸的分解;在浸麦水为中性条件下浸麦,植酸酶活力上升较快,植酸含量迅速下降;在浸麦期间添加Ca2+、Mg2和Fe3+等金属离子对植酸酶的活力有较大抑制作用。     

植酸酶的激活及其催化植酸钠水解提取肌醇

以脱脂米糠为原料提取肌醇,用离子交换树脂吸附植酸,再用NaOH洗脱,得到植酸钠溶液,采用植酸酶阳离子激活提高酶活后催化植酸钠水解,水解液最后用CaCO3溶液破坏水解平衡的原理辅助水解,从而制得得率高达11.5％的肌醇.     

Comparison of folate losses in soybean during the preparation of tempeh and soymilk

The changes in undeconjugated and total folate content of soybean during various stages of tempeh and soymilk preparation were studied. Total folate was extracted by the tri‐enzyme technique. The ratio of total folate to undeconjugated folate was compared in all samples. Raw soybeans used for tempeh and soymilk preparation contained 4.04 and 4.50 mg total folate kg^?1 respectively. Soaking and boiling soybean caused a significant loss of folate during tempeh and soymilk preparation. Leaching was identified as the major cause of folate loss, as soaking and cooking waters were found to contain a large amount of folate. Rhizopus fermentation of boiled soybean caused an increase of 68 and 100% in undeconjugated and total folate contents respectively. Frying reduced the folate content of tempeh significantly. Milling of boiled soybean in soymilk preparation significantly reduced the undeconjugated folate content of blanched soybean but increased the total folate. UHT treatment of soymilk caused a loss of 9 and 14% of undeconjugated and total folates respectively. The total folate content of deep‐fried tempeh and soymilk was 2.35 and 2.76 mg kg^?1 respectively. Analysed values are expressed on a dry weight basis. © 2002 Society of Chemical Industry     

Production of volatile compounds by Rhizopus oligosporus during soybean and barley tempeh fermentation

Rhizopus oligosporus Saito can ferment soybeans or cereal grains to tempeh, a sliceable cake with improved nutritional properties. Volatiles produced by different R. oligosporus strains grown on malt extract agar (MEA), barley and soybean were investigated. The effect of co-cultivation with Lactobacillus plantarum on the production of volatiles was also studied. Volatile compounds were collected in situ by headspace diffusion and identified by GC-MS. The ten R. oligosporus strains that had different colony morphologies on MEA produced very similar volatile profiles, except for slight variations among the minor volatile compounds (e.g. sesquiterpenes). Likewise, practically no differences in volatile profiles were observed between three of the strains grown on soybeans. In contrast, the R. oligosporus volatile profile on soybean was different from that on barley from the same strain. Co-cultivation with L. plantarum did not influence volatile production by R. oligosporus. The dominant compounds produced on all three substrates were ethanol, acetone, ethyl acetate, 2-butanone, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol. Acetaldehyde and 2-methyl-propanal were also produced on MEA and barley, while 2-pentanone, methyl acetate, 2-butanol and 3-methyl-3-buten-1-ol were observed on soybeans. Ethanol, 2-methyl-1-butanol and 3-methyl-1-butanol were the most abundant volatile compounds produced on MEA and barley, while 2-butanone was the dominant volatile metabolite on soybean. The mushroom odour compounds, 3-octanone and 1-octen-3-ol, were only detected from soybean and soybean tempeh.     

Phytate content and phytate degradation by endogenous phytase in pea (Pisum sativum)

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.     

豆豉、纳豆及天培的研究进展

综述了豆豉、纳豆及天培的生产工艺、发展现状、营养功能等,比较了三者的相同点和不同点,并对其前景进行了分析和展望。     

The effect of germination on the phytase activity,phytate and total phosphorus contents of some Nigerian‐grown grain legumes

BACKGROUND: Grain legumes are under‐exploited as possible sources of phytase for the poultry industry. The current study was conducted to assess the effect of germination on phytase activities, phytate and total phosphorus content in samples of Nigerian‐grown grain legumes. The legumes screened were African yambean (AYB, Sphenostylis stenocarpa), lima bean (Phaseolus lunatus), pigeon pea (Cajanus cajan), cowpea (Vigna unguiculata) and groundnut (Arachis hypogea). RESULTS: Phytase activity was low in AYB, lima bean and pigeon pea but high in cowpea and groundnut. Phytate content ranged between 3.01 g kg^?1 and 8.95 g kg^?1 while total phosphorus content ranged between 2.63 g kg^?1 and 5.93 g kg^?1. The grain legumes with higher phytase activity recorded the lowest phytate and phosphorus content. During germination there was an initial 4‐fold to 35‐fold increase in phytase activity after 6–7 days of germination followed by a decrease until 10 days (P < 0.05). The increase in phytase activity during germination was accompanied by a significant reduction in phytate (P < 0.05) and a small but significant increase in total phosphorus. CONCLUSION: The increase in phytase activity and the accompanying decrease in phytate content could have a positive implication for the nutrition of poultry and ruminants and for the environment. Copyright © 2010 Society of Chemical Industry     

Supplementation of alkaline phytase (Ds11) in whole-wheat bread reduces phytate content and improves mineral solubility

Abstract: In this study, alkaline phytase was added to whole‐wheat bread and the phytate content and mineral profiles were compared to commercially available acidic phytase. At neutral pH, some phytate (approximately 20%) was degraded by endogenous phytase in wheat flour, while 40% of phytate was hydrolyzed by alkaline phytase DS11 and a 35% reduction was observed with acidic phytase. Most of the enzymatic activity occurred during the proofing stage, and the rate of reaction depended on pH. DS11 phytase effectively degraded the phytate level within a 30 min treatment at pH 7; however, at least 60 min was needed with acidic phytase to achieve the same hydrolysis level. Mineral profiles were also dramatically affected by the phytate reduction. The biggest increase was observed in Fe²⁺ by the phytase treatment. The Fe²⁺ content increased 10‐fold at pH 7 and 8‐fold at pH 5 with alkaline phytase DS11. Alkaline phytase DS11 was shown to be effective at phytate reduction in whole‐wheat bread preparation. Additionally, phytate degradation enhanced the mineral availability of bread.     

外源性植酸酶在大豆乳中的应用

植物性食物中的植酸不能被单胃动物吸收,但是植酸酶能够水解植酸最终释放出肌醇和无机磷,供单胃动物吸收利用。本实验在研究温度、pH等因素对植酸酶活性影响的基础上,确定植酸酶催化植酸的水解条件为温度45℃、pH4.5、时间2h、酶添加量300FTU/kg。将植酸酶添加到大豆乳中,对大豆乳中植酸/植酸盐进行水解,分析发现大豆乳中有机磷的水解率高达82.9%;植酸酶对大豆乳中植酸/植酸盐的水解作用,对提高大豆乳的营养价值具有重要意义。     

植酸酶降解豆粕粉与玉米粉释放有效磷条件的研究

试验以豆粕粉和玉米粉为底物,研究植酸酶在不同温度、pH值条件下的生物活性.结果表明:以玉米粉为作用对象,植酸酶最适酶解pH值为4.0,最适酶解温度为33℃;以豆粕粉为作用对象,植酸酶最适酶解pH值为4.0,最适酶解温度为35℃.     

Effect of fermentation time on the antioxidant activities of tempeh prepared from fermented soybean using Rhizopus oligosporus

The objective of this study was to evaluate the effect of fermentation time on the antioxidant activity of tempeh, a fermented product from soybean. Rhizopus oligosporus was used to ferment soybean for 0, 1, 2, 5 and 10 days. Lyophilised tempeh powder was extracted with hexane followed by petroleum ether, ether, 95% ethanol and water. Antioxidant activities of the extracts were evaluated with various models including α,α-diphenyl-β-pricryl-hydrazyl (DPPH) and superoxide-scavenging activities, reducing power and inhibitory activity towards lipid peroxidation. The results revealed that tempeh showed greater antioxidant activities than unfermented soybean. On behalf of a DPPH scavenger, water extracts were as good as 95% ethanol extracts. In comparison of superoxide anion-scavenging activity, inhibition of lipid peroxidation and reducing power, 95% ethanol extracts were superior to water extracts. Tempeh fermented with R. oligosporus for 10 days exhibited the highest antioxidant activities than the others.     

响应面法优化植酸酶水解大豆分离蛋白的工艺

以大豆分离蛋白为实验材料,在酶解温度、酶添加量、pH、水解时间等单因素实验的基础上,根据Box-Behnken中心组合实验设计原理,采用四因素三水平响应曲面分析法,依据回归分析确定各工艺条件的主要影响因素,以大豆分离蛋白中植酸的去除率为响应值作响应面。植酸去除的最佳工艺条件为:反应温度44.87℃,酶添加量为8.24%,pH为5.54,反应时间为3.03h。在最佳工艺条件下,植酸的去除率为95.15%,验证实验结果为94.98%。      

Peniophora lycii phytase is stabile and degrades phytate and solubilises minerals in vitro during simulation of gastrointestinal digestion in the pig

BACKGROUND: Microbial phytases (EC 3.1.3) are widely used in diets for monogastric animals to hydrolyse phytate present in the feed and thereby increase phosphorus and mineral availability. Previous work has shown that phytate solubility is strongly affected by calcium in the feed and by pH in the gastrointestinal (GI) tract, which may have an effect on phytase efficacy. An in vitro model simulating the GI tract of pigs was used to study the survival of Peniophora lycii phytase and the effect of the phytase on phytate degradation, inositol phosphate formation and mineral solubilisation during in vitro digestion of a 30:70 soybean meal/maize meal blend with different calcium levels. RESULTS: The phytase retained 76 and 80% of its initial activity throughout the gastric in vitro digestion. Total phytate hydrolysis by P. lycii phytase was in the same range at total calcium levels of 1.2 and 6.2 mg g^?1 dry matter (DM), despite very large differences in phytate solubility at these calcium levels. However, at 11.2 and 21.2 mg Ca g^?1 DM, phytate hydrolysis was significantly lower. The amount of soluble mineral was generally increased by P. lycii phytase. CONCLUSION: Stability of P. lycii phytase during gastric digestion was not found to be critical for phytate hydrolysis. Furthermore, original phytate solubility was not an absolute requirement for phytate degradation; phytate solubility seemed to be in a steady state, allowing insoluble phytate to solubilise as soluble phytate was degraded. This is new and interesting knowledge that adds to the current understanding of phytate–phytase interaction. Copyright © 2007 Society of Chemical Industry     

The localization of phytate in tofu curd formation and effects of phytate on tofu texture

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.     

丹贝冰淇淋的研制

利用正交试验探讨了丹贝粉、奶粉、人造奶油及瓜儿胶的添加量对丹贝冰淇淋膨胀率及感官质量的影响。结果显示，它们对丹贝冰淇淋的膨胀率和感官质量均有显著性的影响。当丹贝粉、奶粉、人造奶油及瓜儿胶的添加量分别为9.0%、5.0%、5.0%和0.2%时，冰淇淋的膨胀率和感官质量均达到最佳。     

植酸酶的研究与应用

对植酸酶的理化特性、功能、应用和亟待解决的问题进行了研究。