Nutritional composition and antinutritional factors of mung bean seeds (Phaseolus aureus) as affected by some home traditional processes

The effects of some domestic traditional processes, such as dehulling, soaking, germination, boiling, autoclaving and microwave cooking, on the nutritional composition and antinutritional factors of mung bean seeds were studied. Germination and cooking processes caused significant (p<0.05) decreases in fat, carbohydrate fractions, antinutritional factors and total ash contents. All processes decreased the concentrations of lysine, tryptophan, threonine and sulfur-containing amino acids. However, all treatments were higher in total aromatic amino acids, leucine, isoleucine and valine contents than the FAO/WHO reference. Dehulling, soaking and germination processes were less effective than cooking processes in reducing trypsin inhibitor, tannins and hemagglutinin activity contents. Also, germination was more effective in reducing phytic acid, stachyose and raffinose. Germination resulted in a greater retention of all minerals compared to other processes. In vitro protein digestibility and protein efficiency ratio were improved by all processes. The chemical score and limiting amino acids of mung bean subjected to the various processes varied considerably, depending on the type of process.     

Nutritional value of cowpea (Vigna unguiculata L. Walp) meals as ingredients in diets for Pacific white shrimp (Litopenaeus vannamei Boone)

The nutritional value of cowpea (Vigna unguiculata L. Walp) meals, as ingredients in diets for Litopenaeus vannamei, was evaluated. Five experimental meals were prepared in the laboratory: whole raw cowpea (WRC), dehulled (DC), cooked (CC), germinated (GC) and extruded (EXC). The crude protein content of WRC (26.1%) increased after germination (29.5%). Carbohydrates ranged from 69.4% to 85.9%. The trypsin inhibitor activity of WRC meal was low (7.52 U/mg dry matter), and was reduced or eliminated by cooking and extrusion. Apparent digestibility of dry matter, protein and carbohydrate of the diet containing whole raw cowpea meal (71.1%, 85.9% and 76.7%, respectively) was similar to the control diet. Cooking and extruding of cowpea significantly increased dry matter, protein and carbohydrate digestibility in the diets. The results suggest that cowpea meals are good sources of nutrients and can be used as ingredients in diets for L. vannamei.     

Effect of soaking and hydrothermal processing methods on the levels of antinutrients and in vitro protein digestibility of Bauhinia purpurea L. seeds

The effects of various domestic processing methods such as soaking, cooking and autoclaving on the levels of certain antinutritional factors and in vitro protein digestibility of seeds of Bauhinia purpurea L., an underutilised legume collected from South India, were investigated. The raw seeds were found to contain antinutritional factors like total free phenolics (2.75 g/100 g), tannins (2.35 g/100 g), phytic acid (692 mg/100 g) and flatulence factors, raffinose (0.54 g/100 g), stachyose (1.17 g/100 g) and verbascose (0.95 g/100 g). Soaking the seeds in distilled water caused maximum reduction in the phytic acid content (37%), whereas soaking in NaHCO₃ solution reduced significant levels of phenolics and tannins (72% and 78%, respectively). A reduction in the levels of oligosaccharides (raffinose by 63%, stachyose by 42% and verbascose by 79%) was observed during cooking. Of the attempted treatments, autoclaving appeared to be most effective in reducing levels of all the investigated antinutrients, except phytic acid, and also improved the in vitro protein digestibility of B. purpurea seeds.     

Thermal aggregation,amino acid composition and in vitro digestibility of vicilin-rich protein isolates from three Phaseolus legumes: A comparative study

The heat-induced aggregation and the in vitro digestibility of vicilin-rich protein isolates from three Phaseolus legumes, including kidney bean, red bean and mung bean were investigated and compared, and their amino acid composition and free sulfhydryl (SH) group contents also evaluated. The results showed that the extent in the heat-induced aggregation varied with the type of the protein isolates, and the formation of new disulphide bonds (at the expense of free SH contents) was involved in the formation of the aggregates. The protein isolates with higher levels of hydrophobic and uncharged polar amino acids, and lower basic amino acid contents exhibited lower extent of their heat-induced aggregation. The in vitro pepsin plus trypsin digestibility was different for various native protein isolates. The digestibility was to a varying extent affected by the heat treatment. The influences of heating on the digestibility of these proteins were closely related to the extent of their heat-induced aggregation. The results suggest that the improvement of nutritional property of those vicilin-rich protein isolates by heat treatment is largely dependent upon their amino acid composition as well as the extent of heat-induced aggregation.     

Effect of soaking and heat processing on the levels of antinutrients and digestible proteins in seeds of Vigna aconitifolia and Vigna sinensis

The effect of soaking, cooking and autoclaving on the levels of total free phenolics, tannins, phytic acid and in vitro protein digestibility (IVPD) were studied in Vigna aconitifolia and Vigna sinensis. Though soaking significantly reduced the content of tannins alone in V. aconitifolia, both total free phenolics and tannins were markedly reduced in V. sinensis. Greater loss of total free phenolics as well as tannins occurred under autoclaving compared to soaking and cooking in both the legumes investigated. In V. aconitifolia, soaking in distilled water for 6 h and cooking for 30 min reduced the phytic acid content by up to 43%. Maximum reduction in the level of phytic acid (36%) was observed under distilled water soaking compared to cooking and autoclaving in V. sinensis. Limited loss in content of phytic acid was noticed under autoclaving compared to soaking and cooking in both the pulses studied. In vitro protein digestibility (IVPD) of V. aconitifolia and V. sinensis was enhanced to 12.5 and 14.8%, respectively, under autoclaving. Of all the processing methods, autoclaving seemed to be the most efficient for reduction in content of the antinutrients, except phytic acid, and improving IVPD in both the pulses.     

Effects of heat treatments of antinutritional factors and quality of proteins in winged bean

The effects of heat treatments, namely microwave, infrared, hot air oven, autoclaving and cooking in boiling water, on trypsin inhibitor and haemagglutinating activities, tannin and phytate contents, essential amino acid composition and quality of proteins in winged bean, were investigated. The infrared, autoclaving and boiling-water treatments destroyed most of the trypsin inhibitor and haemagglutinating activities, and reduced the level of tannins. However, the microwave and oven heat treatments had no effect on these constituents of winged bean meal. Lysine and valine contents in the meals from infrared, autoclaving and cooking in boiling water treatments were lower than in untreated meal. There was a significant loss of threonine and arginine due to cooking of beans in boiling water. None of the treatments had any effect on phytate content. Rats fed on untreated, microwave-treated and oven-heated meal diets had low dry-matter intakes and lost weight significantly. However, remarkable improvements in dry-matter intake and weight gain were recorded for the diets containing meal from infrared, autoclaving and boiling-water treatments. The digestibility of proteins in the meal improved from 50 to 84% as a result of infrared and boiling-water treatments, whereas a noticeable decrease in protein digestibility was observed in oven-heated meals. There was a significant improvement in biological values and net protein utilisation values for the diets containing meals from infrared, autoclaving and boiling-water treatments over those of a diet having untreated meal.     

Effect of germination on the nitrogenous constituents,protein fractions, in vitro digestibility and antinutritional factors of fenugreek seeds (trigonella foenum graecum L.)

This study was designed to determine the effect of germination on nitrogenous constituents, protein fractions, in vitro digestibility and antinutritional factors (namely trypsin inhibitor and haemagglutinin) of the Egyptian fenugreek seeds Geiza 2 variety. After 96 h of germination, there was 18% decrease in the dry weight of seeds, a slight increase of total nitrogen (TN), a decrease of protein nitrogen (PN) and a marked increase of both non-protein nitrogen (NPN) and free amino acid nitrogen (FAAN). Non-protein nitrogen other than FAAN, amido nitrogen and ammonia nitrogen also increased. The protein fractions (namely albumin, globulin, prolamin and glutelin) were separated according to their solubilities in different solvents. The ratio between the four protein fractions in ungerminated seeds was 4:3.5:2.8:1 and became 2:6.5:7.7:1 after germination as calculated on the basis of their PN.Trypsin inhibitor activity per gramme of fenugreek was found to be higher by 66% in germinated fenugreek than ungerminated seeds. Both ungerminated and germinated fenugreek was found devoid of the haemagglutinin activity.Germination resulted in a slight increase in pancreatic digestibility, 33.7% decrease in digestibility by pepsin followed by pancreatin, while a small decrease was found in peptic digestibility.     

Effect of soaking,dehulling, and cooking methods on certain antinutrients and in vitro protein digestibility of bitter and sweet lupin seeds

Effect of several physical treatments (soaking, dehulling, ordinary cooking, microwave cooking, and autoclaving) on the level of antinutrients and in vitro protein digestibility of bitter and sweet lupin seeds were investigated. The raw bitter and sweet lupin seeds were found to contain phytic acid, tannins, trypsin inhibitor activity, and lectin activity, but α-amylase inhibitor was absent. Dehulling significantly increased the levels of phytic acid (PA), trypsin inhibitor activity (TIA), and tannins, but lectin activity was not changed. Also soaking in bitter (for 96 hr) and sweet (for 24 hr) seeds caused a significant increase in these factors except lectin activity. Cooking methods differently affected the levels of the antinutrients. Thus, PA increased but tannins were not changed, on the other hand TI and lectin activities were inactivated; ordinary cooking and autoclaving were the most effective in both seeds. For combination effect, soaking following cooking treatments significantly decreased PA, tannins, and lectin activity, but increased TIA in both seeds. Moreover, dehulling following soaking and cooking methods resulted in a significant increase of PA, TIA, and tannins. In vitro protein digestibility (IVPD) of raw bitter and sweet lupin seeds were 78.55 and 79.46%, respectively and it was improved by all processing methods; soakingdehulling after autoclaving was the most effective in both seeds. Although some treatments increased the level of antinutrients, they improved IVPD. Therefore, the studied antinutrients are not the only responsible factor for lowering IVPD.     

Characterization,amino acid composition and in vitro digestibility of hemp (Cannabis sativa L.) proteins

The protein constituents and thermal properties of hemp (Cannabis sativa L.) protein isolate (HPI) as well as 11S- and 7S-rich HPIs (HPI-11S and HPI-7S) were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and different scanning calorimetry (DSC), and their amino acid composition and in vitro digestibility were also evaluated, as compared to soy protein isolate (SPI). SDS-PAGE analysis showed that the edestin (consisting of acidic and basic subunits, AS and BS) was the main protein component for HPI and HPI-11S, while HPI-7S was composed of the BS of edestin and a subunit of about 4.8 kDa. DSC analysis characterized thermal transition of the edestin component and the possible present form of different subunits. Except lysine and sulfur-containing amino acids, the essential amino acids of various HPIs met the suggested requirements of FAO/WHO for 2–5 year old infants. The proportion of essential amino acids to the total amino acids (E/T) for HPI (as well as HPI-11S) was significantly higher than that of SPI. In an in vitro digestion model, various protein constituents of various HPIs were much easily digested by pepsin plus trypsin, to release oligo-peptides with molecular weight less than 10.0 kDa (under reduced condition). Only after pepsin digestion, in vitro digestibility of HPIs was comparable to that of SPI, however after pepsin plus trypsin digestion, the digestibility (88–91%) was significantly higher than that (71%) of SPI (P < 0.05). These results suggest that the protein isolates from hempseed are much more nutritional in amino acid nutrition and easily digestible than SPI, and can be utilized as a good source of protein nutrition for human consumption.     

A study of the in vitro protein digestibility of indica and japonica cultivars

Protein digestibility was determined in 18 indica and japonica raw milled rices using an in vitro pH-drop method with three- or four-enzyme system. Similar protein digestibility was found between indica and japonica rices, which is in agreement with the in vivo digestibilities in human. Cooking improved protein digestibility in the four-enzyme assay, while reducing agents exhibited apparent inhibition in multienzyme digestibility of indica and japonica rices. A significant correlation was detected between protein content and the estimates of digestibility, whereas no significant correlation was found between amylose content and digestibility estimates. SDS–PAGE analysis showed a significant difference in the degradation extent of prolamin between multienzyme and pepsin digestion, which might contribute to the inconsistence between results of this study and previous findings that in vitro protein digestibility of japonica rice was higher than that of indica rice. In addition, our results supported the previous report that waxy gene product level is not a major determinant of protein digestibility in milled rice.     

Protein quality of germinated Phaseolus vulgaris

Advantages of seed germination consist of an increase in the bioavailability of proteins as well as the change in the antinutritional factors which limit their utilization. Throughout this work, the effects of germination and cooking after germination on the protein in black and white beans (Phaseolus vulgaris) were evaluated. Antinutritional factors that affect the utilization of such protein were also assessed. The amounts of protein, available lysine, tannins, PER, and protein digestibility in vitro and apparent, of beans germinated and germinated-cooked were quantified. The germination significantly (p≤0.05) increased the content of proteins, inactived trypsin inhibitors, and raised the available lysine. Germination and cooking completely inactivated the trypsin inhibitors, which became lysine less available, decreased tannins, and increased protein digestibility and PER value. Differences between black and white beans were observed and attributed to variations in structure, composition, and varieties, among other factors. Cooking complements the effect of germination by improving the protein quality of P. vulgaris and increasing its bioavailability for the human consumption.     

Effects of heating on protein quality of soybean flour devoid of Kunitz inhibitor and lectin

The effects of autoclaving on protein quality of soybean flours prepared from a conventional soybean (CSB) and an isoline lacking Kunitz inhibitor and lectin (KFLF) were studied. The heating was efficient in the urease, trypsin inhibitors and lectin inactivation, being 15 min sufficient to reduce more than 90% of these compounds and provide protein solubility over 80%. The results of PER, NPR and weight gain showed that heating equally improved the nutritional quality of both soybean flours, although higher autoclaving time was required for KFLF. No significant improvement was observed on NPU and in vivo digestibility of the diets containing KFLF at any heating time. As these later results were similar to those obtained with diets containing CSB, they show the importance of the heating to improve the nutritional value and show that other components rather than trypsin inhibitors and lectins impair the nutritive value of raw soybean.     

Physicochemical changes of myofibrillar proteins during processing of Cantonese sausage in relation to their aggregation behaviour and in vitro digestibility

The physicochemical changes of myofibrillar proteins, especially oxidation behaviour, were measured to determine their mechanism of action on in vitro protein digestibility during Cantonese sausage processing. The results indicated that the carbonyl level significantly increased (p < 0.05) during the process. The SH group level decreased, while S–S group level increased gradually. Protein aggregation was induced by oxidation and heat treatment. Result from Fourier transform infrared (FTIR) spectroscopy confirmed protein aggregation occurred. The analysis of in vitro digestibility showed a highly significant (p < 0.05) correlation between pepsin activity and carbonyl group formation, S–S group level, protein surface hydrophobicity, D_4,3. A negative and highly significant correlation between trypsin, α-chymotrypsin activity and carbonyl group formation was measured, while no significant correlation with S–S groups, protein surface hydrophobicity, D_4,3 was observed. It indicated that not only protein oxidation and aggregation but also degradation by pepsin would influence proteolysis with trypsin and α-chymotrypsin.     

Effect of processing on in vitro digestibility of protein and starch in quinoa seeds

The in vitro digestibility of protein in raw quinoa assessed by an enzymic method was 78%, significantly ( P > 0.01 ) lower than that of casein, 91%, and also somewhat lower ( P > 0.01) than that of the raw washed quinoa sample, 83%. the process used to remove the outer layers of the seeds containing saponins increased the protein digestibility significantly ( P > 0.01), by 7%. Heat treatments increased protein digestibility over that of raw quinoa samples. Only the cooked sample treated for 60 min presented a slightly lower protein digestibility, 77%, than those obtained for other heat-treated samples.
The temperature, time and moisture used in cooking and autoclaving of whole seeds of quinoa did not improve starch digestibility significantly. the digestibility of the starch in the raw and precooked samples was 72 and 77%, respectively, after drum drying and about 64% after extrusion in both cases. Precooking at 60°C for 20 min does not improve the digestibility of the quinoa starch.     

Contents and digestibility of carbohydrates of chickpea and black gram as affected by domestic processing and cooking

Starch digestibility (in vitro) and level of total soluble sugars, reducing sugars, non-reducing sugars and starch in cultivars of chickpea (Cicer arietinum), as well as black gram (Vigna mungo), varied significantly. The effects of different domestic processing and cooking methods on the contents of starch, sugars and starch digestibility (in vitro) of eight varieties of chickpea and four of black gram were investigated. Cooking, autoclaving and germination decreased the starch content and increased the level of total soluble sugars, reducing sugars, non-reducing sugars and starch digestibility of both the legumes. Soaking reduced the sugars considerably but starch only marginally. Autoclaving increased starch digestibility more than 4-fold and 5-fold in chickpea and black gram, respectively. Cooking and sprouting also improved starch digestibility appreciably.     

Influence of germination on the nutritional quality of Phaseolus vulgaris and Cajanus cajan

Germination is a method that can modify the presence of nutrients and antinutrients in legume seeds. In this study, the changes in trypsin inhibitors activity (TIA), phytic acid, tannins, ascorbic acid, thiamine, protein digestibility and minerals in germinated black beans (Phaseolus vulgaris L.), white beans (Phaseolus vulgaris L.) and pigeon beans (Cajanus cajan L. Millsp) were evaluated. The ungerminated grains were analysed as control. A significant decrease in the content of TIA of pigeon beans (19.2%), white beans (52.5%) and black beans (25%) was observed. The reduction of phytic acid was more than 40% for the three grains germinated; for the tannins, the reduction was of 14.3% for pigeon beans, 19% for black beans and 36.2% for white beans. Germination increased the protein digestibility in a 2-4% range, and also increased the ascorbic acid by 300% for white beans, by 33% for black beans and by 208% for pigeon beans. The thiamine content increased more than 26.7%. Germination affected the mineral content erratically, depending more on the grain and the type of mineral. These variations in the content of nutrients and antinutrients of the germinated grains are attributed to the joint effect of the germination and previous soaking the grains were subjected to.     

Evaluation of the antioxidant and antiproliferative activities of extracted saponins and flavonols from germinated black beans (Phaseolus vulgaris L.)

Flavonoids and saponins from common beans have been widely studied due to their bioactivity. This research evaluated the effect of germination of black beans (Phaseolus vulgaris L.) on the antioxidant capacity and antiproliferative activity against cancer cell lines of saponins and flavonoids extracted from seed coats, cotyledons and sprouts. Principal component analysis was performed to achieve punctual associations between the black bean saponins and flavonoids concentrations to the antioxidant capacity and the antiproliferative activities. Total phenolic content and antioxidant capacity of extracts were higher when obtained from seed coats, mainly from the 3rd germination day. The extracts obtained from seed coats after 3 and 5 germination days inhibited all cancer cell lines proliferation with no cytotoxicity against control cells. Genistein was related with the activity against mammary cancer cells but flavonols and group B saponins were more related with hepatic and colon cancers. Non-glycosilated flavonols were related with antioxidant capacity.     

Nutritional quality of legume seeds as affected by some physical treatments, Part 1: Protein quality evaluation

The effect of water soaking, boiling, roasting, microwave cooking, autoclaving, fermentation and micronization on the nutritional quality of cowpea, pea and kidney bean was investigated. Pea seeds showed the highest crude fat, crude fiber and the lowest moisture contents while kidney bean had the lowest crude fat and the highest crude protein and ash contents. Glu and Asp were the main amino acids in all legumes while Cys and Met contents were the lowest. The protein efficiency ratio (PER), protein chemical score (CS) and the essential amino acid index (EAAI) of raw seeds ranged from 2.15 to 2.95, 39.07 to 68.30, and 55.49 to 62.84, respectively. Soaking, boiling, microwave cooking and autoclaving increased the total essential amino acids in all samples. Furthermore, raw and treated samples showed higher Lys content than the reference protein. Autoclaving was the most effective in improving protein quality followed by micronization, microwave cooking and fermentation. In addition, in vitro protein digestibility was improved after soaking, boiling, microwave cooking, autoclaving and fermentation but was reduced after roasting and micronization.     

Chemical and nutritional changes in soybean during germination

Germination of soybeans for 6 days depressed the trypsin inhibitor activity by 32%. Oil content, acid value, iodine value and total unsaturated fatty acids of soybean oil decreased while peroxide value and total saturated fatty acids pronouncedly increased. Percentage of palmitic and linoleic fatty acids were highly affected during germination. Analysis of the hydrocarbon and sterol classes revealed n-tricosane and β-sitosterol to be, respectively, the major components. Marked changes in both hydrocarbon and sterol constituents occurred upon germination. Different periods of soybean germination increased non-protein nitrogen and decreased reducing sugars. However, total ash content decreased due to soaking; thereafter it was constant for the rest of the germination period. Different amino acid components increased due to germination when compared with their content in dry seeds. The protein solubility of germinated soybean was higher in H₂O, 5% NaCl and 0·02m NaOH than it was in ungerminated seeds. Water and oil absorption, emulsification and foaming capacities of soybean were increased after germination. A marked improvement in digestibility by pepsin was noticed while tryptic digestibility was still low (38%). PAGE patterns showed drastic changes in both low and high molecular weight protein fractions due to germination.     

Effects of baking on protein digestibility of organic spelt products determined by two in vitro digestion methods

Consumption of organic foods is steadily increasing because it is believed to be healthier than conventional foods. This study was designed to investigate protein digestibility of organic spelt bread, biscuit, cookie and muffin in comparison to their corresponding normal wheat products. Three types of fermented bread products namely, yeast leavened, sour and yeast/sour dough were evaluated. Protein digestibility was assessed based on two methods, three-enzyme one-step and two-enzyme two-step digestion in vitro. The one-step digestion method produced results that were comparable with in vivo (rat) methods whereas the two-step digestion method was more reliable in determining differences among the examined wheat products. Organic spelt used in the present study was comparable to common wheat in protein content averaging 15.4 g/100 g dry matter. Slight differences were observed between organic spelt and common wheat products in protein digestibility determined by the two digestion methods. However, significant differences were found among each wheat products. In general, after baking protein digestion was significantly increased. Spelt and common wheat bread products had similar protein digestibility within each type of bread with sour dough breads had the highest protein digestibility. Biscuit, cookie and muffin products possessed lower protein digestibility than breads. In general, variations in protein digestibility due to baking were more noticeable than that found between the two wheats.