Production of two types of phytase from Aspergillus oryzae during industrial koji making

In our previous study, it was determined that phytase produced by Aspergillus oryzae plays an important role in supplying phosphate to yeast in the process of making sake. During koji making, two types of phytase (Phy-I and Phy-II) are produced. The purified phytases have high thermal and pH stability, in comparison to phytase purified from a submerged culture (ACP-II). In the present study, Phy-I and Phy-II retained their activities for 45 h. The NH2-terminal sequence of Phy-1, which is eight amino acids in length, was identical to that of ACP-II, but the molecular weights of these two forms, as estimated by SDS-PAGE, were quite different from each other (Phy-I, 120 kDa; ACP-II, 58 kDa). From the NH2-terminal amino acid sequence analysis of the predominant phytase (Phy-II), a molecular weight of 116 kDa was expected to reflect a new type of phytase produced only in koji culture. The substrate specificity of Phy-II was sufficiently broad that it hydrolyzed not only phytic acid and p-nitro phenyl phosphate, but also glucose 6-phosphate and glycerol 1-phosphate. In the process of making koji, Phy-I was produced at an early stage, followed by Phy-II; with both phytases being thought to function to hydrolyze phytic acid cooperatively.     

In vitro Effects of Phytic Acid and Polyphenols on Starch Digestion and Fiber Degradation

The effect of phytic acid and polyphenols on the rate and extent of starch digestion as well as on fiber degradation was studied in vitro. Addition of phytic acid only had negligible influence on the enzyme activity of the amylases tested. In contrast, enzymes concerned with starch hydrolysis in the digestive channel (α-amylase, amyloglucosidase/maltase) were inhibited by tannic acid, and to some extent also by catechin. Furthermore, tannic acid reduced the total recovery of starch during enzymic starch analysis. The activity of cellulases and hemicellulases was not affected by phytic acid or catechin. However, the degradation of cellulose powder was inhibited by tannic acid, whereas no inhibition could be observed with carboxymethyl-cellulose as substrate.     

CHARACTERIZATION OF PHYTASE ACTIVITY IN LUPIN SEED

Lupin phytase (myo-inositol hexaphosphate phosphohydrolase) and the degradation of its substrate phytic acid were studied during seed germination. Phytase and acid phosphatase activities were detected in nongerminated seeds and increased from days 1 to 8 of germination, while the concentration of phytic acid decreased during the same period. Phytase was extracted with 2% CaCl₂ solution and partially purified by ammonium sulfate fractionation and HPLC-gel permeation chromatography. Substrate specificites were determined using pnitrophenylphosphate or phytic acid. The pH and temperature optima for the fraction obtained by gel permeation were 5.0 and 50C respectively, while the Km and V _max values were 0.33 mM and 0.13 μmol·mL^?1·min^?1, respectively. It was not possible to separate phytase from phosphatase by use of gel permeation chromatography due to similarities in apparent molecular mass, however resolution of the two enzymes was achieved by DEAE-cellulose chromatography.     

In vitro analysis of binding capacities of calcium to phytic acid in different food samples

The present work was performed to study the role which plays phytic acid in calcium binding, and to determine the calcium binding capacities in different foods, using in vitro extractions. Different food samples (soybeans, oats, chickpea, rice flour, and corn semolina) were extracted for 4 h at 37 °C using artificial simulated gastrointestinal juice (pepsin) at pH=2. The total calcium and phytic acid concentrations were determined by AAS and capillary electrophoresis, respectively, at pH=2 and pH=8 after neutralisation with a sodium hydroxide solution (3 M). Having determined the binding capacities of calcium in each food, we then use these results to estimate the fraction of calcium available for resorption during the process of digestion, when food moves from the acid pH of the stomach to the alkaline milieu of the intestines. The results obtained for the foods analysed show that the capacity of calcium to bind to phytic acid exhibits a clear pH dependence. The calculated calcium binding capacities, or the molar ratio of calcium to phytic acid in the in vitro extracted foods, varies from 3 mol calcium per mol phytic acid for soybean, chickpea and oats, to 2 mol calcium per mol phytic acid for rice, to1 mol calcium per mol phytic acid in corn semolina. Calcium may bind to one or more of the phosphate groups of phytic acid. Previous studies have demonstrated that phytic acid has the ability to bind minerals, proteins, and starch, and have then considered it as an inhibitor to the bioavailability of minerals and trace elements.     

Constitution of leguminous seeds. A note on protein-phytic acid interactions during isolation of acid-soluble protein from phaseolus beans

Acid-soluble proteins isolated from three types of Phaseolus beans (white kidney beans, navy beans and lima beans) were found to contain phytic acid. The amount of phytic acid complexed by the proteins was unaffected by the phytic acid content of the bean extracts from which the proteins were isolated but depended on the number of positively charged basic groups which were available for reaction with the phytate anion. It was found that the Neuberg formula for phytic acid (C₆H₂₄O₂₇P₆) represents more accurately the molecular formula of phytic acid associated with the isolated proteins, than does the Anderson formula (C₆H₁₈O₂₄P₆).     

Characterization of extra- and intracellular phytases from Rhizopus oligosporus used in tempeh production

Rhizopus oligosporus strain CT11K2, commonly used in tempeh (fermented soybean) production produced both extra- and intracellular phytases. The enzymes were isolated from growth media and the cultured mould and partially purified by acetone fractionation, gel filtration on Sephadex G-100 and DEAE-cellulose chromatography. Intracellular phytase activity was higher than that of the extracellular enzyme. Both enzymes showed maximum activity at pH 4.5 and 55 degrees C, suggesting relatively high thermostability. The enzymes were partially inhibited by high concentrations of substrate. The Km and Vmax values of the extracellular phytase were 0.15 mM and 0.076 mumol Pi per min per ml DEAE-cellulose purified enzyme, respectively, and for the intracellular phytase were 0.17 mM and 0.34 mumol Pi per min per ml enzyme, respectively. Extracellular phytases showed inactivation and activation energies for the hydrolysis of phytic acid of approximately 28,300 cal per mol and 6100 cal per mol, respectively, while inactivation and activation energies for the intracellular phytase were approximately 33,200 per mol and 9500 cal per mol, respectively.     

Inositol phosphate content and trypsin inhibitor activity in ready-to-eat cruciferous sprouts

Four cruciferous seeds (small radish, radish, white mustard and rapeseed) were germinated in order to study the fate of inositol hexaphosphate (IP-6, phytic acid) and activity of trypsin inhibitor (TIA). Reduction in the content of phytic acid depended on the time of germination. After four days of germination, when sprouts were ready-to-eat, the amount of this compound was about 50% lower in three out of the four seeds evaluated. Next, a sharp reduction in phytic acid occurred during thermal treatments (pasteurization and sterilization) of germinated rapeseed and radish sprouts. In thermal processes, a decrease in inositol hexaphosphate content was accompanied by the appearance of lower forms of inositol phosphates: IP-5, IP-4 and IP-3.The analysis of TIA, in rapeseed and radish seeds, in four-day sprouts and in these sprouts after thermal treatment, showed that only thermal processes caused complete disappearance this activity.     

放射型根瘤杆菌植酸酶对麸皮中植酸的脱磷作用

采用放射型根瘤杆菌植酸酶粗酶液水解麸皮中的植酸,研究其脱磷的最适条件。依据单因素试验和正交试验获得脱磷的最优条件为加酶量750U/g、底物质量浓度40mg/mL、温度45℃、pH7、时间5h。最优条件下,麸皮中植酸的水解率在5h达最大,为81.50%。     

A Novel Enzyme Application for Corn Wet Milling

In corn wet milling the raw material is prepared by means of steeping. Steeping is required in order to:

• –obtain the valuable CSL (Corn Steep Liquor),
• –soften the kernel and break the cell walls.

SO₂ is added to the steepwater to inhibit bacterial growth. Depending on the type of corn, the steeping time in a semi-continuous steeping system varies from 36 to 60 h, which is substantially longer than all subsequent steps in the process. The corn comprises phytic acid, which to a large extent ends up in the CSL and constitutes an undesirable component. It has now been found that the problem caused by this phenomenon can be avoided by using phytic acid degrading enzymes during steeping. It has further been found, that by adding phytic acid degrading enzymes together with plant cell wall degrading enzymes to the steep liquor, the steeping time can be reduced considerably in a conventional steeping system and even further in a two stage steeping process, whereby the second steeping stage is carried out after course grinding. Also in case conventional steeping times are applied higher starch yields and lower energy consumption may be obtained.     

乳酸菌固态发酵过程中麦麸组分的动态变化

麦麸是小麦加工的主要副产物,营养丰富且产量大,采用乳酸菌处理麦麸可提高其附加值。为明确乳酸菌发酵对麦麸各组分的影响,作者采用植物乳杆菌、鼠李糖乳杆菌、戊糖片球菌和布氏乳杆菌分别对麦麸进行固态发酵,在48 h内每隔8 h取样,分析可溶性膳食纤维、粗蛋白质、淀粉、总酚、植酸等成分的质量分数及DPPH自由基清除能力的动态变化。结果表明,在麦麸基质中,4株乳酸菌在24 h内生长较为迅速;麦麸经乳酸菌发酵后可溶性膳食纤维质量分数显著提高,其中布氏乳杆菌发酵48 h后可溶性膳食纤维质量分数由4.72%增加至6.58%;随着发酵时间的增加,麦麸中淀粉质量分数逐渐降低,粗蛋白质量分数先增加后降低最后趋于稳定;植物乳杆菌在提高麦麸多酚质量分数方面有更好的效果,多酚质量分数由1.34 mg/g增加至3.86 mg/g,麦麸抗氧化活性显著增加;此外,乳酸菌发酵麦麸可显著降低其植酸质量分数。综合而言,植物乳杆菌和布氏乳杆菌在提高麦麸的营养特性方面具有较好的效果,可有效改善麦麸的综合利用价值。     

Phytic Acid Degradation in Complementary Foods Using Phytase Naturally Occurring in Whole Grain Cereals

Complementary foods based on cereals and legumes often contain high amounts of phytic acid, a potent inhibitor of mineral and trace element absorption. The possibility to degrade phytic acid during the production of complementary foods by using whole grain cereals as the phytase source was investigated. Whole grain rye, wheat, or buckwheat (10%) were added to cereal‐legume‐based complementary food mixtures, and phytic acid was shown to be completely degraded in a relatively short time (1.5 to 3 h) when incubated at optimal conditions for cereal phytase. The potential usefulness of the method for industrial production was demonstrated with a complementary food based on wheat and soybean.     

Grain phytic acid content in japonica rice as affected by cultivar and environment and its relation to protein content

Phytic acid and protein contents in grains of japonica rice cultivars collected from different areas of China were assayed in this study. Meanwhile, a multi-location trial was conducted to determine phytic acid content of 24 cultivars grown at 4 locations with wide differences in ecological conditions. For 72 cultivars, phytic acid content ranged from 0.685% for Xiu217 to 1.03% for Huai9746, with a mean of 0.873%, and protein content ranged from 6.45% for Xiu52 to 11.1% for K45, with a mean of 8.26%. There was no significant correlation between grain phytic acid and protein content, suggesting the possibility of breeding japonica rice cultivars with low phytic acid and high protein contents. The effects of cultivars, environments (locations) and their interactions on phytic acid content were all highly significant, with the location having the largest effect. The highly significant interaction between cultivar and environment suggests that the correct evaluation of rice germplasm by phytic acid content should be conducted in multi-environments.     

Effect of roasting and autoclaving on phytic acid content of chickpea

Chickpea cultivars CM-68, C-44, Kabuli, CM-72 and 6153 were analysed for phytic acid, phytate phosphorus and total phosphorus. The effect of roasting and autoclaving on these constituents of whole seed and cotyledons was determined. The data revealed that roasting and autoclaving significantly decreased (P less than 0.05) the phytic acid of chickpea cultivars. Phytic acid of whole seed was reduced to a range value of 16-60% and 16-64% by roasting and autoclaving respectively depending upon the cultivar. In the cotyledon, the phytic acid was reduced to a range value of 32-68% and 18-68% during roasting and autoclaving respectively. Similar effect of these treatments was observed in phytate phosphorus however, total phosphorus was little affected.     

STUDIES ON SOME TECHNOLOGICAL PROPERTIES OF PREDOMINANT LACTIC ACID BACTERIA ISOLATED FROM NIGERIAN FERMENTED FOODS

In a programme to develop starter cultures for improving the safety and quality of traditional fermented foods in Africa, a study was conducted on lactic acid bacterial (LAB) strains isolated from the traditional selected Nigerian fermented foods kunun-zaki, wara, nono, iru. The LAB strains representing the dominating population of each product, were identified as Enterococcus faecalis (1), Pediococcus pentosaceus (4), and Lactobacillus fermentum (19). All the strains grew at 450°C, an observation which could be attributed to the tropical environment of the fermented foods. They produced a moderate spectrum of enzymes of relevance to food processing, and exhibited similar patterns of enzymatic activity between species, but generally showed weak esterase and lipase activities as compared with peptidases. While no proteinase activity was detected, most strains showed high galactosidase activity. Two strains showed ability to degrade phytic acid. None of the strains produced any detectable bacteriocins or biogenic amines under the test conditions used, and all were unable to hydrolyse bile salt. Eleven (45.8%) of the strains coagulated skim milk at 30°C within 24-36 h, and at 37°C within 12-20 h together with a moderate drop in pH. The results are discussed to highlight the relevance of technological features of starter cultures in food processing in the African environment.     

氯化盐处理对绿豆芽菜植酸降解的影响

为降低绿豆芽菜中抗营养物质植酸含量,探究氯化盐对绿豆芽菜植酸降解的影响,研究了KCl、NaCl和CaCl2处理下绿豆芽菜的长势、植酸酶活性及植酸含量的变化,筛选了具有降植酸效果的氯化盐并优化了浓度组合。结果发现,NaCl和CaCl2能够促进植酸降解同时促进绿豆芽菜生长;单因素试验结果表明,1.6 mmol/L NaCl和6 mmol/L CaCl2降植酸效果最佳,且NaCl和CaCl2促进植酸降解作用有叠加效应。响应面法优化得到NaCl、CaCl2浓度分别为1.68 mmol/L和6.40 mmol/L时,植酸含量降低至8.04 μg/株,为对照的10.84%。     

The impact of processing on phytic acid,in vitro soluble iron and Phy/Fe molar ratio of faba bean (Vicia faba L.)

BACKGROUND: Faba bean is one of the important legumes in Asian countries. It is also a major source of micronutrients in many rural areas. Unfortunately, the bioavailability of iron from faba bean is low because it is present as an insoluble complex with food components such as phytic acid. The influence of soaking, germination and fermentation with the expectation of increasing the bioavailability of iron was investigated. RESULTS: Fermentation treatments were most effective in decreasing phytic acid (48–84%), followed by soaking at 10 °C after preheating (36–51%). Steeping faba beans for 24 h at 25 °C had the least effect on the removal of phytic acid (9–24%). With increased germination time at 30 °C, phytic acid progressively decreased from 9 to 69%. Most wet processing procedures, except soaking after wet preheating, caused losses of dry matter and iron (8–15%). In vitro iron solubility, as a percentage of total iron in soaked faba bean after dry preheating, was significantly higher than in raw faba bean (P < 0.05). Fermentation and germination did not have significant effects on the solubility of iron. CONCLUSION: The expected improvement of iron bioavailability levels due to lower phytic acid was not confirmed by increasing levels of in vitro soluble iron. Soaking, germination and fermentation can decrease phytic acid in faba bean. However, results from in vitro solubility measurement of iron showed little improvement of iron bioavailability in fermented and germinated faba beans over untreated raw faba beans (P < 0.05). It seems that componets of dietary fibre other than phytic acid are more important in binding iron. Probably, a complex association between dietary fibre and iron is the reason for the poor bioavailability of iron in faba bean. Copyright © 2009 Society of Chemical Industry     

Preparation of High Bran Arabic Bread with Low Phytic Acid Content

Incubation of wheat bran at pH 5.2 and at a temperature of 55°C for various periods of time caused an increase in the levels of inorganic phosphorus and inositol phosphates and a simultaneous decrease in the level of phytic acid. When Arabic bread containing different levels of bran was prepared, up to 32% of the original phytic acid was lost during the process of bread preparation. Incorporation of wheat malt in the bread formula did not have any effect on phytic acid loss while incubation of bran in an acidic medium followed by repeated decantation of the incubation liquid produced a high bran bread almost free of phytic acid.     

植酸优化黄酒生产工艺的研究

该文试验了植酸对黄酒糖化发酵菌种的影响及在除浊工艺上的应用。结果表明,植酸能促进菌种生长发酵,增加发酵产物,缩短发酵周期;植酸能改善黄酒质量,提高出酒率及原料利用率;植酸用于除浊的最佳浓度为0.04%,处理时间为24h,酒液清亮透明,黄酒的风味和感官均得到改善。     

天然抗氧化剂对红酸汤发酵过程中亚硝酸盐含量及品质的影响

目的 评估茶多酚、抗坏血酸和植酸3种天然抗氧化剂作用下红酸汤发酵过程中亚硝酸盐含量的变化,分析储藏期间天然抗氧化剂对红酸汤品质的影响.方法 利用GB 5009.33—2016《食品安全国家标准食品中亚硝酸盐与硝酸盐的测定》的方法确定红酸汤发酵过程中亚硝酸盐的含量,采用GB 5009.239—2016《食品安全国家标准食...     

Levels of nutritional constituents and antinutritional factors in black gram (Vigna mungo L. Hepper)

A study was conducted on nutritional constituents (total sugars, total proteins, total lipids and starch content) and antinutritional factors such as phenolic compounds, tannins, saponins, phytic acid, trypsin inhibitors and enzymes related to them such as acid- and alkaline phosphatases, ??-galactosidase in eleven recommended cultivars and twenty one advance breeding lines of black gram (Vigna mungo L. Hepper) with an aim to identify genotypes containing high nutritional quality and low antinutritional content. The average content of starch, total soluble sugars, proteins and lipids was around 43.5, 4.84, 22.0 and 1.1%, respectively. Seven genotypes had higher levels of bound fructose contributed by sucrose and raffinose series oligosaccharides. A significant positive correlation was observed among total phenols, o-dihydroxy phenols and flavonols; and among trypsin inhibitors and saponins. The content of phytic acid and activity of trypsin inhibitors showed significant variation among these genotypes. However, not much variation was observed in the content of tannins and saponins. Activities of ??-galactosidase, acid- and alkaline phosphatase were found to be related to the content of bound fructose of raffinose series oligosaccharides and phytic acid respectively. Genotypes having higher activity of these enzymes showed lower content of these antinutritional factors. The results showed that the observed diversity in developed cultivars and advance breeding lines could be further used by plant breeders.