Mineral Composition of Four Indian Food Legumes

Whole seeds and cotyledons of four Indian legumes, chick pea, pigeon pea, green gram, and black gram were compared for their total ash, calcium, phosphorus, iron, magnesium, zinc, manganese, copper, and chromium contents. Varietal differences were significant only for chromium content in black gram. The cotyledons of these legumes were significantly lower in calcium content as compared to the whole grains. From the human nutrition point of view, differences in mineral composition of whole grain and cotyledons were marginal except for calcium. These legumes as whole grain and cotyledons, appeared to be significant contributors to the daily requirements of magnesium, manganese, and copper in the diet.     

Biochemistry of black gram (phaseolus mungo L.): A review

Black gram is one of the less‐known legumes, mainly grown and consumed in India, Thailand, and other tropical parts of the world. This review presents the information on black gram (Phaseolus mungo L.) proteins (albumins, globulins, prolamins, and glutelins), minerals (calcium, magnesium, phosphorus, zinc, and iron), vitamins, lipids, phytic acid, carbohydrates, antinutritional factors (α‐amylase inhibitor, trypsin and chymotrypsin inhibitors, tannins, and phytohemagglutinins), and flatulence production in rats following ingestion of black gram processed products. Effects of different food processing operations (germination, cooking, and fermentation etc.) on black gram proteins, carbohydrates, phytic acid and flatus factors are also discussed.     

Total and soluble contents of calcium, magnesium, phosphorus and zinc in yoghurts

This paper examines the content of major minerals (calcium, magnesium, phosphorus and zinc) and its distribution between soluble (non-sedimentable) and micellar fractions of 16 commercial yoghurts from five different branches. These elements were determined by atomic absorption spectrometry after mineralisation by dry ashing. Total mineral contents showed wide intervals of variation (calcium 1090–2050 mg l⁻¹, magnesium 101–177 mg l⁻¹, phosphorus 878–1560 mg l⁻¹ and zinc 4.0–7.3 mg l⁻¹) due to the addition during manufacturing of different dairy products or fractions. Most of the minerals were found in the non-sedimentable fraction. Practically all calcium was measured in the supernatants of ultracentrifugation. Lower proportions of magnesium and zinc were determined in the non-sedimentable fraction (between 87 and 96%) whereas the lowest ones (63–77%) were found for phosphorus.     

Storage Proteins of Glandless Cottonseed Flour

The salt-soluble storage protein isolate of defatted glandless cottonseed flour was separated by gel filtration column chromatography into six fractions (I to VI). Column and thin-layer gel filtration showed that these fractions had molecular weights of >600,000, 280,000, 127,000, 63,500, 10,700, and <2,000, respectively. Treating fraction I protein with dilute alkali dissociated a component that migrated upon gel filtration with fraction VI. Both fractions I and VI were yellow and the color intensified at alkaline pH, suggesting the presence of bound flavonol and gossypol pigments. Because of its large size and low (16.6%) protein content, fraction I was thought to be fragments of membrane and aleurone gram globulins. Gradient polyacrylamide gel electrophoresis (PAGE) showed that the proteins in each fraction being completely recovered from column chromatography were represented in the pattern of the initial isolate. The proteins in fractions II and III have similar ammo acid compositions, except that III is low in methionine, cystine and tryptophan and II is low in tyrosine and phenylalanine. The amino acid composition of fraction I was also similar to fractions II and III, while unique patterns were noted for fractions V and VI. Fraction VI was rich in lysine and arginine.     

Improving mineral availability in soymilk by dephosphorylation of phytic acid using an alkaline phytase from Bacillus amyloliquefaciens DS11

To enhance mineral availability in soymilk, the alkaline phytase from Bacillus amyloliquefaciens DS11 was applied to degrade the phytic acid in soymilk, and resulting effects on mineral profiles were assessed. Nearly 60% of phytic acid was degraded within 25 min by treatment with 0.090 unit/mg of phytate, whereas most phytic acid was removed in 125 min using 0.18 unit/mg of phytate. Compared to a control, the free calcium, magnesium, phosphorus, and iron contents significantly (p<0.05) increased by 1.9, 1.8, 4.0, and 4.0×, respectively, after 125 min of reaction using 0.18 unit/mg of phytate. Free minerals were released from the phytate complex by enzymatic dephosphorylation, resulting in enhancement of mineral availability in soymilk. Alkaline phytase DS11 has a great potential for enhancing the mineral availability in neutral pH phytate-rich foods, like soymilk.     

Studies on black gram (Vigna mungo) trypsin inhibitor

The trypsin inhibitor fraction from black gram was isolated by ammonium sulphate fractionation (0-75%). It exerted maximum inhibition on trypsin and to a less extent on the endopeptidases, chymotrypsin, papain, pronase and pepsin in vitro, In-vitro digestibility of the raw black gram was found to be lower than autoclaved black gram and autoclaved black gram supplemented with native black gram trypsin inhibitor. Haemagglutinating activity was absent in the black gram extract as well as in the black gram trypsin inhibitor fractions. During the last 48 h of germination there was a steep decline in trypsin inhibitory activity and an increase was observed later. Trypsin inhibitory activity was greater in the leaves than the cotyledons during the fourth, fifth and sixth days of germination.     

Physiology of Bengal gram seed. III.—changes in the phosphorus compounds of the seed parts during ripening of the seed

Seed parts of Bengal gram have been studied for their total, acid-soluble, inorganic, phytin and phosphatide phosphorus fractions at different stages of seed development. Except for the phytin phosphorus in the cotyledons and phytin and total phosphorus in the embryo (i.e. excluding the cotyledons), all phosphorus fractions decreased over the period of sampling. Largest decreases occurred in the seed coat which is commensurate with its metabolic necessity. The cotyledons have been found to contribute largest amounts to the content of the phosphorus fractions in the whole seed, though at early stages of maturity, the seed coat also contributes a fairly large proportion.     

Effects of Phytic Acid, Divalent Cations, and Their Interactions on α-Amylase Activity

The effects of phytic acid and its interactions with divalent cations (Ca⁺⁺ and Mg⁺⁺) on α-amylase activity were investigated in model systems. Amylase activity was influenced by both preincubation time with phytate as well as phytate concentration. At 6-30 mM concentrations, Ca⁺⁺ and Mg⁺⁺ ions lowered the enzyme activity by 9-34% and 24-49%, respectively. When divalent cations were added simultaneously with phytate, a slight increase in enzyme activity with Ca⁺⁺ and lowered enzyme activity with Mg⁺⁺ were observed, as compared to when added independently. The enzyme activity was only moderately lowered when phytate was first preincubated with the divalent cations. Amylase inhibition by phytate was found to be of noncompetative type with an apparent inhibitor constant of 1.75 mM under the assay conditions.     

Nutrient Losses Due to Scarification of Pigeonpea (Cajanus cajan L.) Cotyledons

Outer layers of cotyledons of pigeonpea cultivar C 11 were successively scarified using a Tangential Abrasive Dehulling Device (TADD). Scarification for 0; 2, 4, 8, and 12 min resulted in the removal of 0, 6.7, 12.7, 25.3, and 36.9%, respectively, of powder fractions. The cotyledons and powder fractions at each level of scarification were analyzed for chemical composition, including minerals and trace elements, protein fractions, amino acid composition, and trypsin inhibitor acitivity (TIA). Protein, soluble sugars and ash of the dhal fraction (scarified cotyledons) decreased with increasing scarification time, while starch content increased. Considerable amounts of calcium (about 20%) and iron (about 30%) were removed by scarification for 4 min, but the process did not adversely affect protein quality in terms of amino acids. Trypsin inhibitors were not removed substantially by scarification.     

Enzymatic Reduction of Phytate in Whole Wheat Breads

The presence of phytate in flour may be responsible for reduced bioavailability of iron, magnesium, zinc, and calcium from bread. The effect of various concentrations of commercial phytase or phosphatase added to whole wheat flour-yeast doughs on their phytate and nonphytate phosphorus content has been investigated. By using 2.0% (flour basis) of phytase and 0.11% phosphatase the initial phytate phosphorus concentration of the dough was reduced to 1/8 and 1/12 of its initial values, respectively. Storage of the whole wheat breads for up to 96 hr at room temperature showed further significant reduction of phytate phosphorus. The phytate phosphorus content of yeast leavened whole wheat breads decreased during 2 hours of dough fermentation, baking and the subsequent 48 hours of storage at room temperature from 24 mg/100g dough (dry matter) to 1.7 mg/100g bread (dry matter); the phytate phosphorus continued to decrease and after 96 hours storage it was 0.6 mg/100g bread.     

Changes in Chemical Composition of Winged Bean (Psophocarpus tetragonolobus L.) during Seed Development

Three cultivars of winged bean were analyzed for total dry matter, crude fat, nitrogenous constituents, phosphorus, calcium, magnesium, zinc, iron, copper and cooking behavior at different stages of seed maturity. Accumulation of dry matter, crude fat and nitrogen occurred during seed development whereas nonprotein nitrogen and tryptophan contents decreased significantly. Reduction in poly-phenol content was observed at all the stages of seed development. There was a significant decrease in total phosphorus content with concomitant increase in the proportion of phytate phosphorus throughout the seed development. In matured seeds, phytate phosphorus accounted for 66—73% of total phosphorus. A reduction in zinc content was noticed in all the cultivars studied. In contrast, calcium, magnesium, iron and copper contents of seeds of different stages of maturity did not exhibit marked differences.     

Effect of malting and fermentation on antinutrients,and total and extractable minerals of high and low phytate corn genotypes

Two corn genotypes, Var‐113 (high phytate) and TL‐98B‐6225‐9 × TL617 (low phytate), were germinated for 6 days. The germinated grains were dried and milled. A mixture of 5% malt and 95% corn flour was fermented for 14 days. Phytic acid and polyphenol contents and hydrochloric acid (HCl) extractability of minerals from the fermented flours were determined at the intervals of 2 days during fermentation. Phytic acid and polyphenol contents decreased significantly (P ≤ 0.05) with an increase in fermentation time, with a concomitant increase in HCl‐extractable minerals. For both genotypes, the major mineral content was increased, while that of trace minerals was increased but at slow rate with fermentation time. When the grains were fermented for 14 days, TL‐98B‐6225‐9 × TL617 genotype had higher extractable calcium and Var‐113 had higher extractable phosphorus, whereas iron and manganese recorded high extractability levels in Var‐113. There was good correlation between phytate and polyphenol level reduction and the increment in extractable minerals with fermentation time.     

PROTEIN-PHYTATE INTERACTIONS IN SOYBEANS. II. MECHANISM OF PROTEIN-PHYTATE BINDING AS AFFECTED BY CALCIUM

Phytate and bovine serum albumin were used in a model system to investigate the mechanism of their binding. Ultrafiltration studies using response surface design showed the association of protein and phytic acid to be highly pH dependent. Under acid conditions, the protein formed an insoluble complex with phytic acid. At pH 3.0, a binding constant of 2.3 times 10⁵ was obtained and it was calculated that there are 78 binding sites of the total 93 basic amino acid residues potentially available. This low pH complex was not disrupted at high temperatures but the presence of calcium ions caused dissolution of the precipitate. Calcium produced different effects at higher pH (> 6). Soluble protein-calcium-phytic acid complexes were formed which were less stable to heat and dissociated above pH 10 at high ionic strength. Since this interaction occurred only in the presence of calcium, a salt linkage is implicated in which divalent cations simultaneously bind to the protein and phytic acid in the form of a soluble complex. It is proposed that either the addition of divalent cations at low pH or sequestering agents at high pH would best effect the removal of phytate from soy products by ultrafiltration.     

Bioavailability of calcium and magnesium from faba beans (Vicia faba L var major), soaked in different pH solutions and cooked,in growing rats

The nutritive utilisation of calcium and magnesium from faba beans (Vicia faba L var major), soaked in different pH solutions and then cooked, was studied in growing rats. Prior to the cooking process the beans were soaked in acid (pH 2.6 and 5.3) or basic (pH 8.4) solutions. Processing of the bean seeds did not produce appreciable losses of Ca or Mg by solubilisation. Digestive utilisation of calcium was high and did not vary with the different processing conditions assayed. Metabolic utilisation of calcium was significantly improved by soaking and by soaking plus cooking. Both digestive and metabolic utilisation of magnesium were significantly improved by all the different processes assayed. The observed improvement in the nutritive utilisation of Ca and Mg was correlated with a higher weight gain of the animals but not with the content of these minerals in the femur and longissimus dorsi muscle. The higher dietary intake of cellulose, lignin and phytate found in the processed faba bean diets did not have a negative effect on the digestive utilisation of the minerals studied. Overall, soaking in basic solution plus cooking was the most effective treatment. The processing conditions studied were inexpensive and easily applied and have great potential for application at household or industry level for human and animal nutrition. Copyright © 2004 Society of Chemical Industry     

Mineral and Phytic Acid Partitioning Among Air-Classified Bean Flour Fractions

Hull flours and air-classified intermediate starch, high starch, and high protein navy, pinto, and black bean flours were analyzed for mineral content and phytic acid. Phytic acid content ranged from 4.29-8.72 mg/g in the high starch flours to 23.74-30.22 mg/g in the protein flours. Total phosphorus content proved to be a good indicator of phytic acid content. Zinc, iron, potassium, and magnesium partitioned into the protein flours of each bean type. Strong and significant correlation coefficients obtained between phytic acid content and the content of these minerals, and between the content of these minerals and protein content suggest that metallic phytate complexes were present.     

Zinc and iron contents and their bioaccessibility in cereals and pulses consumed in India

Several cereals and pulses commonly consumed in India were screened for zinc and iron contents and their bioaccessibility in the same was determined by equilibrium dialysis employing an in vitro simulated digestion procedure. Zinc content of cereals ranged from 1.08 mg/100 g in rice to 2.24 mg/100 g in sorghum. Zinc content of pulses was between 2.03 mg/100 g (whole chickpea) and 2.68 mg/ 100 g (decorticated chickpea). Iron content of cereals ranged from 1.32 mg% in rice to 6.51 mg% in sorghum, while that of pulses ranged from 3.85 mg% in decorticated green gram to 6.46 mg% in black gram. Dialyzability of zinc from pulses (27–56%) was generally higher than that from cereals (5.5–21.4%). Dialyzabilities of iron were almost similar from both cereals and pulses examined and were 4.13–8.05% in cereals and 1.77–10.2 % in pulses. A significant negative correlation between inherent phytate content and zinc dialyzability value was inferred in the case of pulses. Phytic acid content of the cereals had a significant negative influence on iron dialyzability. Inherent calcium had a negative influence on zinc dialyzability in cereals. Tannin did not have any significant influence on zinc or iron dialyzabilities from cereals and pulses. While both insoluble and soluble fractions of the dietary fibre generally interfered with zinc dialyzability, the insoluble fraction alone had this effect on iron dialyzability. The lower collective negative influence of the inherent factors on zinc dialyzability from pulses is consistent with their higher concentrations in these grains, relative to cereals. The negative correlation of inherent phytic acid with zinc and iron dialyzabilities was supported by enhanced dialyzabilities of these minerals upon partial removal of phytate from the grains by treatment with fungal phytase.     

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.     

Correlations of the Composition,Minerals, and RVA Pasting Properties of Various Potato Starches

Multiple linear regression equations were developed to correlate the granule size distribution, composition, and minerals content with the Rapid Visco Analyser (RVA) pasting properties of potato starches of different cultivars. From the experimental values and the values of the regression coefficients, it could be observed that a higher level of amylose resulted in a lower peak viscosity (PV) and breakdown (BD) and higher setback (SB) and peak viscosity temperature (PVT) in the potato starches. The reverse was observed when the phosphorus content was higher. Smaller granule size was associated with a decrease in the PVT, whereas larger granules demonstrated higher PV, BD, and SB values in the potato starches. A higher calcium content was associated with a decrease in PV and an increase in BD, SB, and PVT. On the other hand, higher potassium was associated with an increase in PV, BD, SB, and PVT. The sodium contents demonstrated a higher PV and SB, and the reverse was observed in the BD and PVT. It is difficult to conclude the precise role of magnesium ions to the RVA properties although as divalent cations, they may have similar effect as calcium. From the positive and negative values of the regression coefficients it was shown that the correlation is useful for determining more precise values of the RVA pasting properties using a multiple linear regression equation. The correlations were also useful for predicting the effects of the starch composition and minerals on the RVA pasting properties.     

The influence of certain metal ions on the visible spectra of food dyes

Summary. The visible absorption spectra of twenty-two food dyes have been plotted both in the free state and in the presence of added calcium, magnesium, aluminium, iron (II), iron (III), copper (II) and cobalt (II) ions at the pH values 3.0, 6.4, 7.4 and 12.5.
The frequencies of the absorption band maxima of the free dyes are briefly discussed in relation to colour and structure. While added metal ions do not, in general, have an appreciable effect on the spectrum of the dye, the transition metal ions studied frequently bring about a shift in the characteristic frequencies of the free-dye absorption maxima. Examples of where this effect is greatest are carmoisine in the presence of copper (II) at pH 6.4 and 7.4, and black PN in the presence of iron (II) at pH 12.5.
The possibility of dye complexes affecting iron metabolism is also briefly discussed.     

Minerals,phytic acid,tannin and rutin in buckwheat seed milling fractions

The composition of common buckwheat (Fagopyrum esculentum Moench) seed milling fractions depends upon the relative abundance of various seed tissues in each. Fancy (light) flour contains mainly central endosperm, while the bran milling fraction has seed coat and some embryo tissues. Phytate, found in protein bodies of embryo and aleurone cells, is the major storage form of phosphorus, potassium, magnesium and some microelements in seeds. Phytic acid (35–38 g kg^?1) and minerals are concentrated in bran, a milling fraction with high concentrations of phytate‐rich tissues. Polyphenolics, including condensed tannins (proanthocyanidins), are also concentrated in bran (11–15 g kg^?1). Rutin is concentrated in the hull of common buckwheat (0.8–4.4 g kg^?1). Rutin concentration is low (0.2–0.3 g kg^?1) in groats of common buckwheat but higher (0.7–0.8 g kg^?1) in bran containing hull fragments. Rutin is 300‐fold more concentrated (81 g kg^?1) in groats of tartary buckwheat (Fagopyrum tataricum (L) Gaertn) than in groats of common buckwheat. Only small amounts of quercetin were detected. Bran is a concentrated source of phytic acid and tannins, a consideration in consumption of large amounts of buckwheat bran for nutritional or medicinal purposes. © 2001 Society of Chemical Industry