Hydrochloric acid extractable minerals and phytate and polyphenols contents of sprouted faba and white bean cultivars

Two faba bean (Hudieba-72 and Bsabir) and three white bean (Serge, Giza and RO21) cultivars were sprouted for 6 days. The sprouted grains were dried and milled. Phytic acid and polyphenols contents and hydrochloric acid (HCl) extractability of minerals from the malt flours were determined at intervals of 2 days during sprouting. Phytic acid and polyphenols contents decreased significantly (P ? 0.01) with increase in sprouting time with concomitant increase in HCl extractable major and trace minerals. The contents of both major and trace minerals were slightly increased with sprouting time. When faba bean seeds were sprouted for 6 days, Bsabir had higher extractable Ca, while Hudieba-72 had higher P, whereas Fe and Mn recorded high level in Hudieba-72. When white bean seeds were sprouted for 6 days, RO21 cultivar had higher extractable Ca, while Giza-3 cultivar had higher P, whereas Fe and Mn recorded high levels in Serge and RO21 cultivars, respectively. There was a good correlation between phytate and polyphenols reduction and increase in extractable minerals with increase in sprouting time for all cultivars.     

Effect of germination and pure culture fermentation on HCl-extractability of minerals of pearl millet (Pennisetum typhoideum)

Germination significantly increased inorganic P, non-phytate P and phosphorus extractable in 0.03 N HCl, the concentration of acid found in human stomach, with a corresponding decline in phytate P of pearl millet grains. HCl-extractability of calcium, iron, zinc, copper and manganese, an index of their bioavailability to humans, was also significantly improved by germination. Fermentation of pearl millet sprouts with mixtures of yeasts ( Saccharomyces diastaticus or Saccharomyces cerevisiae ) and lactobacilli ( Lactobacillus brevis or Lactobacillus fermentum ) generally improved extractability of the minerals of the sprouts, probably because of the decreased content of phytic acid in the germinated and fermented pearl millet sprouts.     

In vitro Extractability of Calcium, Iron, and Zinc in Finger Millet and Kidney Beans During Processing

ABSTRACT: Finger millet ( Eleusine coracana ) and kidney beans ( Phaseolus vulgaris ) were processed by soaking, germination, autoclaving, and fermentation for incorporation into a complementary food for children. Extract-ability of calcium, iron, and zinc were determined by in vitro HCl-Pepsin and Pepsin-Pancreatin methods after each processing step. Germination significantly increased the in vitro extractability of these minerals, while soaking, autoclaving and fermentation showed a smaller or insignificant effect. Iron extractability was low in germinated, autoclaved and fermented millet, as determined by the pepsin-pancreatin method, but increased 6.8 times with addition of vitamin C. Phytic acid was reduced by 85 and 66% in finger millet and kidney beans, respectively, during the overall processing. These results show that various processing methods, especially germination, increase mineral extractability. Addition of vitamin C and mango could be used to enhance mineral extractabilities, thereby helping to alleviate micronutrient deficiencies in populations subsisting on these foods.     

Effects of Heat and Fermentation on the Extractability of Minerals from Soybean Meal and Corn Meal Blends

Autoclaving (121°C for 30 min) soybean meal reduced phytate phosphorus by 17.5%; phosphorus soluble in 0.03N HCl decreased 27.1%, and iron decreased 17.2%. Heat treatment increased (P < 0.05) extractability of zinc and potassium (soluble in 0.03N HCl) in soybean meal. A natural lactic acid fermentation of corn meal decreased phytate phosphorus by 77.8% and increased phosphorus soluble in 0.03N HCl by 37.9%. Phosphorus and iron from corn meal soluble in 0.03N HCl decreased in quantity when soybean meal was added. There was little difference in the % magnesium, zinc and potassium soluble in 0.03N HCl whether in corn meal or corn meal-soybean meal blends.     

Fermentation and enzyme treatment of tannin sorghum gruels: effects on phenolic compounds,phytate and in vitro accessible iron

The presence of polyphenols and phytate in cereal products has been shown to interfere with the bioavailability of minerals such as iron. In the present study, we added enzymes (wheat phytase and mushroom polyphenol oxidase) during fermentation of tannin sorghum gruels prepared from flour with or without addition of 5% flour of germinated tannin-free sorghum grains (power flour), and investigated the effects on phenolic compounds, phytate and in vitro accessible iron. Assayable phenolic compounds were significantly reduced by fermentation, with high reductions observed in gruels with added enzymes. Fermentation of the gruels with addition of enzymes reduced (on average) total phenols by 57%, catechols by 59%, galloyls by 70% and resorcinols by 73%. The phytate content was significantly reduced by fermentation (39%), with an even greater effect after addition of power flour (72%). The largest reduction of phytate (88%) was, however, obtained after addition of phytase. The in vitro accessible iron was 1.0% in the sorghum flour and it increased after fermentation with power flour and/or with enzymes. The highest in vitro accessibility of iron (3.1%) was obtained when sorghum was fermented with addition of power flour and incubated with phytase and polyphenol oxidase after the fermentation process.     

Effect of fermentation on HCl extractability of minerals in Rabadi-an indigenous fermented food of India

Pearl millet flour/buttermilk mixture was fermented at 35, 40, 45 and 50°C for 3, 6 or 9 h to prepare rabadi. Fermentation at all temperatures decreased phytate P, increased non-phytate P and increased HCl extractability of P, Ca, Fe, Zn and Cu; the extractability increased with an increase in the period of fermentation. The largest improvement was seen in extractability of Fe, followed by that of P, Zn, Ca and Cu. Mn extractability did not change as a result of fermentation.     

Investigations on winter season Sudanese sorghum cultivars: effect of sprouting on the nutritional value

Physicochemical attributes of sorghum grains of Wad Ahmed (summer season cultivar), Abu Ragaba and Abu Kunjara (winter season cultivars) were compared. Floury endosperms characterise grains of all cultivars. Grains of Abu Ragaba and Wad Ahmed are white and Abu Kunjara are coloured. Grains were sprouted for 24, 48 and 72 h and changes in nutrients, tannin, phytic acid, protein digestibility and total and extractable minerals were studied. The nutrients and antinutients contents significantly (P ≤ 0.05) varied between cultivars. High tannin characterises Abu Ragaba and Wad Ahmed. In vitro protein digestibility of the cultivars is comparable. Contents and HCl‐extractability of Ca, P and Fe are varied. Abu Ragaba had the higher HCl‐extractability of the minerals. Sprouting changed contents of the nutrients, reduced significantly (P ≤ 0.05) tannins and phytic acid and increased digestible protein in all cultivars. Reduction of tannins was the highest in Abu Ragaba. The magnitude of reduction increased as sprouting prolonged.     

Effect of malt pretreatment on phytate and tannin level of two sorghum (Sorghum bicolor) cultivars

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.     

Biochemical composition of infant weaning food fabricated from fermented blends of cereal and soybean

Infant weaning foods were produced from fermented blends of germinated and ungerminated cereal–soybean flour paste, using Saccharomyces cerevisiae and L. plantarum ATCC 10776 as starter cultures. A shorter fermentation period of less than 24 h was obtained compared to the traditional 72–96 h. Protein content of the formulated blends increased with fermentation, ranging from 15.5% in F25B to 18.2% in F410B. This could be attributed to the breakdown of nutrients of the substrates especially soybean, by the starter organisms. The relative decrease in the calcium and phosphorus content of the fermented blends could have resulted from leaching during the steeping stage and subsequent loss from the discarded pomace of the grains which contained most of the minerals. Fermentation also provided optimal pH for the degradation of the phytate phosphorus constituents of the formulated blends. The observed increase in the riboflavin, thiamine, niacin, ascorbic acid and some of the amino acids of the fermented blends could be due to the metabolic activities of the fermenting microorganisms. Porridges made from all the formulated cereal-soybean blends were rated above average in terms of overall acceptability, but F15B had the highest preference rating. ©     

萌发玉米粉对发酵的影响

本文研究了萌发6d的玉米粉对乳酸发酵和面包面团发酵的影响.实验结果表明,作为添加成分,在乳酸发酵中,萌发玉米粉可以促进乳酸菌的生长,提高其产酸量,并使发酵乳的粘度迅速增加.在面包面团发酵中,萌发玉米粉能够促进酵母菌的增殖,增加面团持气性,缩短发酵时间.     

Effect of natural fermentation on phytate and polyphenolic content and in-vitro digestibility of starch and protein of pearl millet (Pennisetum typhoideum)

Natural fermentation at 20, 25 and 30°C for 72 h brought about a significant reduction in phytic acid content of pearl millet (Pennisetum typhoideum Rich) flour. The phytate content was almost eliminted in the flour fermented at 30°C. An increase in polyphenol content of fermented flour was noticed, the higher the temperature of fermentation the greater was the increase in polyphenol content of pearl millet. An improvement in starch as well as protein digestibility (in vitro) was noticed at all the temperatures of natural fermentation, the highest being at 30°C.     

Lactic Fermentation of Non-Tannin and High-Tannin Cereals: Effects on In Vitro Estimation of Iron Availability and Phytate Hydrolysis

The effect on iron availability estimated in vitro and phytate hydrolysis was investigated in non-tannin and high-tannin cereals, lactic fermented as flour/water slurries or gruels. A natural starter culture initiated fermentation and addition of germinated flour and phytase in the fermentation process was tested. Lactic fermentation of nontannin cereals with added flour germinated sorghum seeds or wheat phytase increased iron solubility from about 4% up to 9 and 50%, respectively. Soaking flour in water before adding starter culture had a similar effect. The increase in soluble iron was strongly related to enzymatic deeradation of phytate (p<0.001). The reduction of inositol hexa- and pentaphosphates was about 50% with added germinated flour. Reduction was > 90% after soaking the flour prior to fermentation and almost complete with 50 mg phytase added. High-tannin cereals showed a minor increase in soluble iron after fermentation, ascribed to the inhibitory effect of tannins (both on iron solubility and on enzymatic hydrolysis of phytate). Lactic-fermented cereal foods have a potential in developing countries to improve iron nutrition.     

玉米淀粉深层发酵生产L－乳酸

本文报道了使用米根霉（ＲｈｉｚｏｐｕｓＯｒｙｚａｅ）ＴＬ－５２７－９菌株用玉米淀粉深层发酵生产Ｌ－乳酸。探讨了不同碳源、氮源、底物浓度、液化条件、通气量、种龄对Ｌ－乳酸生成的影响，在３Ｍ３发酵罐中，当玉米淀粉投料浓度为１３％时，７罐平均产Ｌ－乳酸９．４１ｇ／１００ｍｌ，对糖转化率７９．５５％。发酵液经分离提取精制，Ｌ－乳酸纯度达９８％以上。同时在研究过程中利用高压液相色谱测定了Ｌ－乳酸代谢变化。本结果表明米根霉ＴＬ－５２７－９菌株具有Ｌ－乳酸产率高和发酵快的特点。     

Effect of food processing of pearl millet (Pennisetum glaucum) IKMP‐5 on the level of phenolics,phytate, iron and zinc

Pearl millet is consumed as a staple food in semi‐arid tropical regions. With a view to upgrading the micronutrient status of pearl millet‐based foods, the effects of single operations and of porridge preparation scenarios on levels and in vitro solubility (IVS) of iron and zinc and mineral complexing factors (phytates: inositol phosphates and phenolic compounds) were tested. Disc milling of grain may add significant iron but this is not necessarily IVS iron. Soaking of grains results in a 25% loss of iron, but also facilitates endogenous phytate degradation, particularly when combined with milling and cooking. Germination and lactic acid fermentation both result in partial phytate degradation. Cooking does not decompose phytates, but results in complex formation of phenolic compounds as measured by a significant reduction in reactive hydroxyl groups. Because of its different distribution in the grain, zinc is generally less affected than iron. Phytate reduction by endogenous phytases is inhibited at low pH as caused by fermentation. Kanwa (alkaline rock salt) could be a functional cooking ingredient as a source of minerals and to react with phenolic substances. The relative IVS of iron was doubled by germination of grain and increased 3‐fold by fermentation of wholemeal slurry. Zinc IVS tended to increase on cooking with kanwa, but decreased in cooked fermented flour. Copyright © 2006 Society of Chemical Industry     

The effects of germination,fermentation, and fermentation additives on the phytate content of rice flour

The phytate contents in nine rice cultivars (Oryza sativa cv.) grown in Korea were investigated and the effects of germination, fermentation, and fermentation additives on the phytate content of rice flour were studied. In nondehulled paddy rice, the phytate content was the highest in Goamibyeo and the lowest in Hanareumbyeo. In milled rice, the phytate content was the highest in Suweon517 and the lowest in Manmibyeo. For Goamibyeo, which had high phytate contents both before and after milling, there was a significant (p<0.05) reduction in the phytate content of paddy rice after germination. The phytate content reduction occurred when germinated paddy flour was fermented at 50°C for 24 h. Paddy rice phytate was completely removed when ammonium sulfate was added to germinated paddy rice flour, which was then allowed to ferment at 50°C for 24 h.     

Effect of malt pretreatment on phytic acid and in vitro protein digestibility of sorghum flour

Sorghum seeds of cultivar Wad Ahemed (phytate: 2.7 mg/g, tannin: 0.96% and 2 h pepsin digestion: 18%) were germinated for three days to obtain 1-, 2- and 3- days old sorghum malts. Sorghum malt was added in concentrations of 1, 2.5, 5, 7.5 or 10% to sorghum flour. The mixtures were incubated with shaking for 0, 30, 60, 90 or 120 min. Phytic acid and in vitro protein digestibility were assayed for all treatments. The results revealed that phytate content was significantly reduced. The 10% 3-day-old malt after 120 min incubation, reduced the phytate content by 83%. The in vitro protein digestibility (IVPD) was significantly improved as a result of malt pretreatment. The rate of reduction of phytate content and the rate of increment in IVPD increased with time of incubation, age and concentration of the malt.     

Phytic acid interactions in food systems

Phytic acid is present in many plant systems, constituting about 1 to 5% by weight of many cereals and legumes. Concern about its presence in food arises from evidence that it decreases the bioavailability of many essential minerals by interacting with multivalent cations and/or proteins to form complexes that may be insoluble or otherwise unavailable under physiologic conditions. The precise structure of phytic acid and its salts is still a matter of controversy and lack of a good method of analysis is also a problem. It forms fairly stable chelates with almost all multivalent cations which are insoluble above pH 6 to 7, although pH, type, and concentration of cation have a tremendous influence on their solubility characteristics. In addition, at low pH and low cation concentration, phytate‐protein complexes are formed due to direct electrostatic interaction, while at pH >6 to 7, a ternary phytic acid‐mineral‐protein complex is formed which dissociates at high Na concentrations. These complexes appear to be responsible for the decreased bioavailability of the complexed minerals and are also more resistant to proteolytic digestion at low pH. Development of methods for producing low‐phytate food products must take into account the nature and extent of the interactions between phytic acid and other food components. Simple mechanical treatment, such as milling, is useful for those seeds in which phytic acid tends to be localized in specific regions. Enzyme treatment, either directly with phytase or indirectly through the action of microorganisms, such as yeast during bread‐making, is quite effective, provided pH and other environmental conditions are favorable. It is also possible to produce low‐phytate products by taking advantage of some specific interactions. For example, adjustment of pH and/or ionic strength so as to dissociate phytate‐protein complexes and then using centrifugation or ultrafiltration (UF) has been shown to be useful. Phytic acid can also influence certain functional properties, such as pH‐solubility profiles of the proteins and the cookability of the seeds.     

Effect of rabadi fermentation of barley on HCl-extractability of minerals

Rabadi fermentation of raw (freshly ground) as well as autoclaved barley flour at 30, 35, and 40°C for 6, 12, 18, 24, and 48 h brought about a significant increase in HCl-extractability of iron, copper, zinc, manganese, calcium, and phosphorus; longer periods and higher fermentation temperatures increased HCl-extractability. Increased non-phytate phosphorus and inorganic phosphorus in the fermented product, with a corresponding decrease in phytate phosphorus, was maximum at 40°C for 48 h and minimum at 30°C for 6 h. The level of phytic acid was significantly negatively correlated with HCl-extractability of minerals in the fermented products.     

普洱茶发酵过程中不同外源添加物对氧化酶活性与成分变化的影响

研究了添加不同外源物对云南普洱茶发酵过程中氧化酶活性及成分变化的影响。结果表明,添加不同外源物的发酵普洱茶中抗坏血酸酶活性变化较大:发酵10 d时,酶活性大小依次表现为焦性没食子酸(没食子酸(水(甘氨酸(葡萄糖;发酵20 d时,酶活性大小依次表现为水(没食子酸(葡萄糖(焦性没食子酸(甘氨酸;发酵30 d时,酶活性大小依次表现为焦性没食子酸(葡萄糖(水(甘氨酸(没食子酸。而多酚氧化酶酶活性均呈下降趋势,以一翻样(发酵10 d)最高。发酵前后,添加不同外源物的发酵茶样中茶黄素无明显变化,茶多酚和茶红素含量大幅减少,茶褐素含量大幅增加。这说明,外源添加葡萄糖、没食子酸、焦性没食子酸和甘氨酸对普洱茶发酵过程中酶活性和成分有较大影响,可加速茶褐素的形成。     

Nutritive Value of Germinated Corn and Corn Fermented After Germination

Sprouts of germinated corn were significantly (P < 0.01) higher in ascorbic acid, riboflavin, and niacin than nongerminated corn. Corn fermented after gemination was significantly (P < 0.01) higher in riboflavin and niacin than nongerminated corn but not germinated corn. Corn fermented after germination was significantly (P < 0.01) higher in percent relative nutritive value (%RNV) than both the germinated and nongerminated corn. Corn chips prepared with germinated and germinated-fermented corn meal were significantly (P < 0.05) higher in riboflavin, niacin and %RNV, and were acceptable to a taste panel. Fresh corn sprouts, when compared to mung bean sprouts by a taste panel, were significantly (P < 0.01) sweeter and more bitter.