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.     

Effect of domestic processing and cooking on the antinutrients of black gram

Domestic processing and cooking methods including soaking, ordinary and pressure cooking of soaked and unsoaked seeds, and sprouting significantly lowered phytic acid, saponin and polyphenol contents of black gram (Vigna mungo) seeds. Soaking for 18 h removed 28% of the phytic acid; extents of removal were higher with longer periods of soaking. Saporins andpolyphenols were relatively less affected. Loss of the antinutrients was greater when soaked instead of unsoaked seeds were cooked. Pressure cooking had a greater effect than ordinary cooking. Antinutrient concentrations declined following sprouting; the longer the period of germination the greater was the reduction. Phytic acid was reduced to a greater extent than polyphenols or saponins.     

EFFECT OF PROCESSING ON NUTRITIONAL AND ANTINUTRITIONAL FACTORS OF MOONGBEAN CULTIVARS

Ordinary cooking of presoaked and unsoaked seeds of six cultivars of moongbean (Vigna radiata L.) lowered phytic acid, polyphenols, trypsin inhibitors and improved in vitro digestibility of protein and starch, and availability of Ca, Fe and Zn when compared to unprocessed seeds. However, the effect was more pronounced on ordinary cooking of presoaked seeds followed by cooking of unsoaked seeds and presoaked seeds alone. A significant increase in vitro digestibility of protein (34–48%), and starch (31–62%) may be ascribed to the reduced content of phytic acid (45–65%) polyphenols (34–70%) and trypsin inhibitor activity (42–55%) after ordinary cooking of presoaked seeds of moongbean cultivars. Therefore, ordinary cooking of soaked seeds was the most effective treatment in improving the nutritional quality of moongbean.     

Effect of Domestic Processing and Cooking on In Vitro Protein Digestibility of Moth Bean

Protein digestibility (in vitro) of dry seeds of moth bean cultivars varied significantly from 58.69 to 62.06%. The protein digestibility improved significantly when the seeds were given different domestic processing and cooking treatments including soaking, sprouting, ordinary cooking and pressure cooking. Pressure cooking of the seeds presoaked in plain water or mixed mineral salt solution had the most pronounced effect.     

Starch and protein digestibility of newly released moth bean cultivars: Effect of soaking, dehulling, germination and pressure cooking

Effect of soaking (12 h), soaking (12 h) dehulling, germination (60 h) and pressure cooking on starch and protein digestibility of four varieties of moth bean, one Local commonly used by the farmers of the area and three newly released high yielding varieties, Jwala, RMO 225 and RMO 257, was studied. The starch digestibility of raw unprocessed moth bean cultivars differed significantly (P < 0.05) from 25.4-28.2 mg maltose released/g flour being the highest and lowest in RMO 257 and RMO 225, respectively. The protein digestibility differed significantly from 70.3-74.6 per cent among all the unprocessed varieties of moth bean. All the processing treatments namely soaking, dehulling, germination and pressure cooking brought about appreciable enhancement in protein digestibility (1-19%) over the control and starch digestibility (19-115%) of all the four moth bean cultivars. However, out of all the processing treatments, germination (60 h) of soaked seeds (12 h) was the most effective in bringing about improvement in digestibility of starch and protein followed by dehulling and soaking (12 h).     

Content of phytic acid and HCl-extractability of calcium,phosphorus and iron as affected by various domestic processing and cooking methods

ICPL-87, the high yielding cultivar of pigeon pea (Cajanus cajan) released by ICRISAT (International Crop Research Institute for Semi-Arid Tropics), India was subjected to various domestic processing and cooking methods, i.e. soaking (6, 12, 18 h, 30°C), soaking (12 h) and dehulling, ordinary as well as pressure cooking and germination (24, 36 and 48 h, 30°C). The unprocessed seeds of this variety contained considerable amounts of phytic acid, (857 mg per 100 g). This was reduced significantly (P<0.05) by 6–28%, 30%, 4–32%, 4–36%, 35–45% in soaked, soaked-dehulled, ordinary as well as pressure cooked and germinated seeds, respectively. Except for soaking and dehulling, the remaining processing and cooking methods did not lower the contents of total calcium, phosphorus and iron. HCl-extractability of these dietary essential minerals, an index of their bioavailability, was enhanced significantly when the pigeon pea seeds were processed and cooked, possibly due to reduction in phytate content, which is known to chelate the minerals. A significant and negative correlation between the phytic acid and HCl-extractability of minerals further strengthens these findings.     

Effect of Processing on Certain Antinutrients in Seeds of Şeker Variety (P. vulgaris L.) Grown in Turkey

Abstract

The effects of different cooking/autoclaving methods were investigated on sucrose, raffinose, stachyose, phytic acid, and tannins content of ?eker bean seeds (Phaseolus vulgaris). All these oligosaccharides and antinutrients decreased under various cooking/autoclaving treatments. Among the different cooking/ autoclaving treatments, 18 h sodium bicarbonate solution soaking followed by autoclaving procedures were the most effective for removing oligosaccharides (65–72%), phytic acid (51%), and tannins (100%). These conditions could be recommended to remove undesirable sugar contents and antinutrients of the ?eker bean used for culinary purposes.     

Formulation and characterization of hypo allergic weaning foods containing potato and sprouted green gram

Potato flour, green gram flour (sprouted as well as unsprouted), were blended in different proportions with apple pulp (10 %), sugar (10 %), milk and water for formulation of 12 hypo allergic diets. Diets were studied for physico-chemical properties, antinutrient content (phytate and oxalate) and invitro protein digestibility. Blending and sprouting significantly affected all the studied parameters. Sprouting significantly (P ≤ 0.05) improved protein content and invitro protein digestibility while carbohydrate content and antinutrients decreased significantly. Nutrition profile of water-based diets met RDA guidelines only after addition of sprouted green gram flour and were comparable to control (commercial weaning food). Water based formulation showed lower sensory score than milk based diets however; addition of sprouted green gram flour significantly (P ≤ 0.05) improved their overall acceptability. It could be concluded that by incorporating sprouted green gram flour, milk could be replaced with water for production of hypo allergic weaning foods without affecting the nutritional and sensory attributes of formulations and thereby making the production more economical especially for under developed countries.     

Nutritional value of African yambean (Sphenostylis stenocarpa,L): improvement by solid substrate fermentation using the tempeh fungus Rhizopus oligosporus

The tropical African yambean (AYB, Sphenostylis stenocarpa L.) is a hardy, protein‐rich under‐utilised African legume. Anti‐nutrients, and the excessively long cooking time (4–6 h), among other factors, limit the food use of African yambean seeds. To reduce these limitations, non‐traditional, less energy consuming processing methods are required. Seeds of different varieties were (1) examined for proximate composition and (2) fermented with Rhizopus oligosporus for the production of tempeh. The traditional production process involves dehulling, soaking in water for 24 h, boiling in water for 30 min, inoculation and fermentation. In addition, the traditional procedure for preparing tempeh was modified by using 1% citric acid solution instead of water for soaking and cooking. Comparisons with traditionally cooked beans, which involved boiling in water for 4 h, were made. The traditional tempeh procedure resulted in a slight but significant increase in protein and starch (P < 0.05) and an almost complete loss of most of the anti‐nutrients of AYB seeds, although the cyanogenic glycoside content of AYB‐white remained high. The modified procedure resulted in a bacteria‐free tempeh and the cyanogenic glycosides were no longer detectable. In vitro protein digestibility of the 1% citric acid treated sample was slightly lower than that of the water‐treated sample. Both tempeh production processes were clearly more effective and less energy intensive than traditional cooking in improving nutritional quality, but only the modified method of tempeh production eliminated the possibility of cyanide poisoning. Copyright © 2006 Society of Chemical Industry     

Phytic acid content of chickpea (Cicer arietinum) and black gram (Vigna mungo): varietal differences and effect of domestic processing and cooking methods

Phytic acid content of various cultivars showed a narrow variation: 7.48-8.00 g kg^?1 and 6.47-6.68 g kg^?1 for chickpea (Cicer arietinum L) and black gram (Vigna mungo L), respectively. Phytic acid was lowered significantly by the common methods of domestic processing and cooking including soaking, cooking, autoclaving and sprouting of the legume grains. Sprouting had the most marked phytic acid lowering effect followed by autoclaving and soaking. Cooking of soaked seeds lowered phytic acid by 20-26% in chickpea and 35-40% in black gram grains whereas the loss was 7-11% and 6-9% in these pulses, respectively, when unsoaked seeds were cooked.     

Effect of processing on starch digestibility in some legumes — An in vitro study

The effect of processing treatments on the rate of starch digestibility in three legumes, viz., bengal gram (Cicer arietinum L.), cowpea (Vigna unguiculata) and green gram (Vigna radiata) was studied using an in vitro dialysis system. The processes studied were fermentation, germination, pressure cooking and roasting. The released sugars measured as glucose equivalents after 3 h digestion were expressed as digestibility index (DI). All the processing treatments except roasting, increased the rate of starch digestibility in all the three legumes. Subsequent cooking of the germinated/fermented legumes lead to a further increase in starch digestibility. The results of the study indicate that ‘slow release’ property of legumes is heat labile and that loss of this property is independent of macro-nutrient and starch content.     

Studies on digestibility of selected legume carbohydrates and its impact on the ph of the gastrointestinal tract in rats

A study on the digestibility of legume carbohydrates in unprocessed and processed grain and also in the starch isolated from the grain was carried out by in vitro and in vivo methods. The legumes selected were red gram (Cajanus cajan cv. Hyd. 3A), Bengal gram (Cicer arietinum cv. BEG 482), black gram (Phaseolus mungo cv. T9) and green gram (Phaseolus aureus cv. PS 16). The processes tested were boiling, pressure cooking, roasting, germination, fermentation and parching. The digestibility in vitro was assessed on the basis of maltose released after amylolysis and digestibility in vivo was assessed on the basis of carbohydrate intake and excretion. Digestibilities of the Phaseolus varieties were superior to red gram and Bengal gram. Roasting did not improve the digestibility of any legume as much as boiling and pressure cooking. The digestibility of fermented and germinated legumes was not much higher than the legumes processed by other methods. The increasing order of digestibility in vivo was red gram < Bengal gram < black gram and < green gram. Significant differences were noticed in the digestibility in vivo of moist and dry heat-treated legumes, and between Phaseolus starches and red gram and Bengal gram starch. The pH values of stomach, duodenum and small intestine contents of rats fed legume diets was greater than the pH values at similar sites in rats fed casein protein, whereas the pH values in the caecum of rats fed on legume diets was acidic and that of casein-fed rats was neutral. Caecum weight of rats fed on red gram and Bengal gram diets was significantly higher (P<0.05) than black gram- and green gram-fed groups.     

Effects of Hull Scratching,Soaking, and Boiling on Antinutrients in Japanese Red Sword Bean (Canavalia gladiata)

The effects of hull processing, soaking, and boiling on the content or activity of antinutrients in the red sword bean (RSB; Canavalia gladiata) were investigated. RSB seeds were compared with kidney bean (KB; Phaseolus vulgaris) seeds that are starch based and often used as processed products in Japan. RSB seeds had higher weight, thicker hull, and higher protein content, but lower moisture content compared with KB seeds. Because of the strong and thick hull, the relative water absorption of untreated RSB seeds was very low after soaking. Seeds were soaked after dehulling, scratching, and roasting. The results showed that hull scratching was the optimal method for increasing water absorption during soaking compared with dehulling and roasting. After soaking, the water used for soaking was discarded, since it had a high content of polyphenols and bitter taste, and RSB seeds were boiled in fresh water for 20, 40, and 60 min. The results showed that polyphenol and tannin contents, antioxidant activity, and hemagglutinating activity, as well as maltase, sucrase, and trypsin inhibitor activities in scratched RSB seeds decreased significantly after boiling compared with those in raw seeds, whereas amylase inhibitor activity showed no significant change. Overall, it was concluded that the combination of hull scratching, soaking, and boiling in fresh water can reduce thermal‐stable or sensitive antinutrients in RSB and thus, significantly improve its nutritional value.     

Nutritional and antinutritional composition,in vitro amino acid availability,starch digestibility and predicted glycemic index of differentially processed mucuna beans (Mucuna pruriens var. utilis): an under-utilised legume

The effects of different solutions, water, 0.07% sodium bicarbonate, 0.1% ascorbic acid and 3% moringa leaf powder in water, and soaking, followed by autoclaving, on the proximate composition and antinutrients, in vitro amino acid digestibility, starch hydrolysis index (HI) and glycemic index (GI) of Mucuna pruriens var. utilis seeds were evaluated. Even though none of the processing techniques affected the proximate composition on gross energy value, they significantly (P<0.05) reduced the levels of various antinutrients, such as total phenolics, tannins, phytates, saponins, l-dopa, trypsin inhibitor (TI), chymotrypsin inhibitor (CI) and lectin activities of the respective samples. Nonetheless, all the processing methods improved the total protein digestibility and individual amino acid availabilities, particularly those of methionine, tyrosine, lysine and arginine, without affecting the protein quality. When compared to the raw seed sample, all the hydrothermal processing increased the total (TS) and digestible (DS) starch content (351–361 and 303–315 g kg⁻¹, respectively) and decreased the resistant starch (RS) content (46.1–48.1 g kg⁻¹) significantly (P<0.05). The in vitro starch digestion rate was also measured in the freshly processed seed samples, and the values of HI and GI were comparable to that of similarly processed legumes such as moth bean and black gram.     

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.     

Polyphenols of chickpea and blackgram as affected by domestic processing and cooking methods

The effects of soaking, cooking, autoclaving and sprouting on the polyphenol contents of eight cultivars of chickpea (Cicer arietinum) and four of blackgram (Vigna mungo) were studied. All the treatments reduced the polyphenols of the legume seeds, but to a varying extent. Sprouting and autoclaving had the most pronounced effect; ordinary cooking and soaking were relatively less effective.     

The impact of germination and dehulling on nutrients, antinutrients, in vitro iron and calcium bioavailability and in vitro starch and protein digestibility of some legume seeds

The content of nutrients (protein, starch, ash, calcium, iron, phosphorous and thiamin) and antinutritional components (dietary fiber fractions, phytic acid and tannin), and in vitro bioavailability of calcium and iron and in vitro digestibility of protein and starch were determined in control, germinated and dehulled green gram, cowpea, lentil and chickpea. Germination caused significant (P<0.05) increase in protein, thiamin, in vitro iron and calcium bioavailability and in vitro starch and protein digestibility contents of all the legume samples. Further increase in mentioned parameters was observed after dehulling the germinated legumes. Phytic acid and tannin were reduced by 18-21% and 20-38%, respectively, on germination and more reduction was observed in dehulled over germinated samples. There were negative correlations between nutrients bioavailability and digestibility with antinutritional factors.     

Thermal heat processing effects on antinutrients,protein and starch digestibility of food legumes

Thermal heat processing effects were investigated on antinutrients, protein and, starch digestibility of black grams, chick peas, lentils, red and white kidney beans. The tannin and phytic acid contents in these five food legumes ranged from 770–1100 mg/100 g to 970–1440 mg/100 g, respectively, whereas protein and starch digestibilities of the raw food legumes were 33.0–37.6% and 36.8–42.0%, respectively. Reduction in the levels of antinutrients, along with an improvement in protein and starch digestibility, was observed after cooking these food legumes. Antinutrient, including tannin (33.1–45.7%) and phytic acid (28.0–51.6%) contents, were reduced by different thermal heat treatments (121AC10, 121AC20, 121AC40, 121AC60, 121AC90, 128AC20). Maximum improvement in protein (95.7–105%) and starch (117–138%) digestibilities was observed on cooking these food legumes at 121 °C for 10 min (121AC10). However, ordinary cooking resulted in improvement of protein and starch digestibilities of the food legumes by 86.0–93.3% and 84.0–90.4%, respectively.     

PROCESSING OF LEGUMES: RESISTANT STARCH AND DIETARY FIBER CONTENTS

Resistant starch (RS) and dietary fiber contents of differently processed Bengal gram (chickpea), black gram, green gram and red gram (pigeon pea) dhals were determined. In traditionally cooked dhals, RS increased 1.6 to 9 fold, whereas pressure cooked dhals showed a 2.1 to 8 fold increase over that of uncooked dhals. Deep fat frying of a black gram food product resulted in a 3 fold increase in RS. Germination of the whole legumes resulted in only a small increase in RS; but the content of insoluble dietary fiber was higher. Pressure‐cooking of red gram dhal in the presence of additives showed considerable variation in the yield recovery of RS. Lactic acid and ascorbic acid, added after cooking, enhanced (>100%) RS; addition of hydrocolloids had only marginal effects; whereas addition of spice powder before cooking lowered RS, an effect similar to the one observed upon addition of oils/lipids.