Changes in differently processed soya bean (Glycine max.) and lima bean (Phaseolus lunatus) with particular reference to their chemical composition and their mineral and some inherent anti-nutritional constituents

The effects of 3 processing techniques: cooking, roasting and autoclaving on the proximate chemical composition, the mineral content and some inherent toxic factors of soya and lima beans were investigated. The processing techniques generally reduced the crude fibre levels and enhanced the extractable fat in the soya and lima beans. The coefficients of variability for crude fibre and ether extract due to the processing techniques of soya and lima beans were 20.9%, 16.0% and 22.3%, 38.1%, respectively. In parallel with decreased ash content in the cooked bean samples, there was a decrease in the K, Mg, Na and P levels relative to the raw bean and also relative to the other processing techniques. Mineral contents of the autoclaved bean samples were generally similar to those of the raw (unprocessed) samples. Under the processing conditions, roasting caused the highest reduction in thioglucoside content (59%) in soya bean while cooking caused the highest reduction in lima bean (78%). Trypsin inhibitor activity (TIA) ranged between 0.59 mg/g sample in the cooked soya bean and 11.6 mg/g sample in the raw bean while the corresponding values for lima bean ranged between 0.59 and 6.3 mg/g sample. Cooking and roasting caused over 90% reduction of TIA, while autoclaving caused 64-69% reduction in both bean samples. Under the assay conditions, haemagglutinating activity was not detected in the cooked and autoclaved soya and lima beans. The need to prevent both functional and nutritional damage to food proteins and other nutrients, resulting from excessive heating, was discussed.     

Effect of various indigenous processing methods on the α‐galactoside and mono‐ and disaccharide content of an Indian tribal pulse,Mucuna pruriens var utilis

The effect of various treatments, such as soaking in different solutions, cooking of raw and soaked seeds, autoclaving of raw and soaked seeds, dehusking of water‐soaked seeds, fermentation of water‐soaked/dehusked seeds, autoclaving of fermented seeds, dry heating of raw seeds and germination, on the levels of mono‐ and disaccharides and α‐galactosides in two varieties of an Indian tribal legume, mucuna bean (Mucuna pruriens var utilis), was investigated. The levels of raffinose, stachyose and verbascose decreased under various treatments. Among the different soaking and cooking/autoclaving treatments, tamarind pulp extract soaking and sodium bicarbonate solution soaking followed by autoclaving procedures were the most effective for removing α‐galactosides (68.4–70.9 and 68.5–68.9% respectively). The lowest reduction of α‐galactosides (8.4–17.2%) was observed in dry‐heated samples. Germination for more than 72 h resulted in the highest reduction of total α‐galactosides (93.6 and 89.6% in white and black varieties respectively). During the germination process, glucose, fructose and sucrose concentrations increased significantly. © 2001 Society of Chemical Industry     

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.     

ENDOGENOUS PHYTATE-DEGRADING ENZYMES ARE RESPONSIBLE FOR PHYTATE REDUCTION WHILE PREPARING BEANS (PHASEOLUS VULGARIS)

The three dry nonprocessed bean varieties contain high amounts of phytate ranging from 9.3 to 15.9 μmol g^-1 dry basis, representing 85 to 89% of total myo-inositol phosphates, while the other myo-inositol phosphates were found only in small or trace amounts. Myo-inositol phosphate concentrations were not affected by soaking in water for 15h at 25C, whereas cooking resulted in a significant reduction in phytate content (16 to 24%) with a concomitant increase in the concentrations of the lower myo-inositol phosphates. The sum of phytate and myo-inositol pentakisphosphate after soaking and cooking represents about 93% of the amount in raw beans. Therefore, preparing of beans has only a limited effect on the content of myo-inositol phosphates with inhibitory effects on mineral absorption. Phytate-degrading enzymes (phytases) were identified as responsible for phytate removal during cooking, since a good correlation between phytase activity and phytate hydrolysis was observed.     

THE EFFECT OF PROCESSING ON THE TRYPSIN INHIBITOR, HEMAGGLUTININ, TANNIC ACID AND PHYTIC ACID CONTENTS OF SEEDS OF TEN COWPEA VARIETIES

Trypsin inhibitor (TI) and hemagglutinin activities, tannic acid and phytic acid contents were determined in ten varieties of cowpea. The different varieties were subjected to four processes; cooking, soaking, autoclaving and germination. TI and hemagglutinin activities were completely eliminated by cooking and autoclaving, while tannic acid and phytic acid contents were only partly affected. Cooking reduced tannic acid contents by 31.0–47.3%. Soaking for three days decreased TI activity by a mean of 31.2%, hemagglutinin activity by 19.0%, tannic acid by 13.4% and phytic acid by 24.4%. Maximum germination effects on TI and hemagglutinin activities were obtained in 'Westbreed' and 'Kano 1696' where percentage losses amounted to 57.2 and 57.6, respectively. The phytic acid contents of all varieties were greatly reduced by germination.     

The cyanogenic glycoside contents of raw and processed limabean varieties

Eighteen varieties of limabean (Phaseolus lunatus), were subjected to the processes of cooking, autoclaving, soaking in water and germination for 6 days. The effects of these processes on the free and bound HCN contents of the raw limabean varieties were investigated. Total HCN in the raw varieties ranged from 265 mg kg^?1 in TPL 071-33 and 553 mg kg^?1 in TPL 13. Considerable variability was encountered in the different varieties and processing effects tended to make these varietal differences even more pronounced. Autoclaving gave a mean total loss of 53·9% in total HCN content while cooking effected a 64·8%–81·9% loss in total HCN content. Drastic reductions in both free and bound HCN contents were obtained in all cooked varieties. Soaking for 2 days effected the highest HCN loss in TPL 2 (40·1%), closely followed by TPL 13 (39·7%) and then TPL 3 (35·4%). All varieties, by the sixth day of soaking, lost between 61·3 and 86·4% of their total HCN contents. The effect of germination on HCN contents increased progressively from a mean total loss of 24·5% in day 2 to 55·6% in day 4 and 76·1% in day 6. Cooking and germination for 6 days appeared to be equally effective in reducing free and bound contents. Autoclaving was the least effective of all the processes studied.     

Effect of processing on available carbohydrate content and starch digestibility of kidney beans (Phaseolus vulgaris L.)

The effects of different soaking and cooking methods were investigated on available carbohydrate content and starch digestibility of red and white kidney beans. Total soluble sugars, reducing sugars, non-reducing sugars and starch contents of red and white kidney beans were 9.95 and 11.3%, 0.82 and 0.96%, 9.13 and 10.3%, and 44.4 and 47.8%, respectively. All these available carbohydrate components decreased to various extents as a result of soaking and cooking. From 2.51 to 13.6% and 7.03 to 28.0% of total soluble sugars were lost on soaking kidney beans in tap water and sodium bicarbonate solution, respectively. However, losses in total soluble sugars were maximum (19.9–60.9%) on cooking pre-soaked kidney beans. Losses in starch contents were 4.27 to 24.7% and 30.4 to 70.7% as a result of the soaking and cooking processes, respectively. Besides these losses, starch digestibility of kidney beans was also markedly improved as a result of cooking. However, no appreciable improvement in starch digestibility was observed after soaking kidney beans in water or alkaline solution.     

Effects of Blanching, Soaking, and Cooking on the HCN Yields, Nitrogen, Ash, and Minerals of Lima Beans (Phaseolus lunatus)

Blanching, soaking, and cooking two cultivars of lima bean reduced the HCN concentrations to a safe level. Beans soaked for 12 hr had lower HCN levels than those soaked for 6 hr. Traditional processing was also effective in reducing the HCN concentration in the beans. The treatment of the beans also resulted in a reduction in ash, and the concentration of some minerals.     

Saponin content of chickpea and black gram: Varietal differences and effects of processing and cooking methods

Differences were observed in saponin contents of eight varieties of chickpea (Cicer arietinum) and four of black gram (Phaseolus mungo). Common domestic processing and cooking treatments reduced the saponin level of the pulses significantly. Sprouting had the most pronounced effect followed by autoclaving, soaking and ordinary cooking. Cooking of soaked as well as unsoaked seeds had a similar diminishing effect.     

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.     

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.     

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 different processes on the carbohydrates of lima bean

Changes which occurred in the concentrations of free sugars, high-molecular weight carbohydrates (water-soluble carbohydrates, starch, hemicellulose, cellulose), and lignin in 3 differently processed varieties of lima bean have been studied. Samples were boiled, autoclaved or soaked in water and germinated for 3 days. Available carbohydrates (starch + sugars) which initially ranged from 53.3 to 54.8 g/100 g dry matter in the raw varieties, decreased very drastically with germination whilst raffinose disappeared and stachyose + verbascose were reduced to trace levels. Cooking as well as autoclaving brought about slight decrease in glucose, fructose and sucrose levels and increased oligosaccharide content of all the varieties. Changes in the content of the structural carbohydrates of all processed varieties were small. Cooking and germination, however effected some reductions in total unavailable carbohydrate content. The effect of these processes on improving the nutritional value of lima beans was discussed.     

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     

IMPROVING ENZYMATIC REDUCTION of MYO-INOSITOL PHOSPHATES WITH INHIBITORY EFFECTS ON MINERAL ABSORPTION IN BLACK BEANS (PHASEOLUS VULGARIS VAR. PRETO)

Activation of endogenous or addition of exogenous phytases during food processing gives a chance to reduce the phytate content in the final product to a nutritionally acceptable level. Optimal conditions for the endogenous phytases of black beans, this is 60C and pH 6.0, resulted in a 55% reduction in 1P₆ after soaking and cooking. the sum of 1P5 and 1P₅ was reduced by 54%. 1P₆ reduction was most extensive when black beans were soaked at 50C while adding exogenous phytases during the last 2 h of soaking. After soaking and cooking 1P₆ was degraded by 85% and the sum of 1P6 and 1P5 was reduced by 82 % compared to the values in raw beans when adding Escherichia coli phytase. Using rye phytase the values were estimated to be 73% and 70%, thereby a clear accumulation of IP₄ occurred. Thus, a significant improvement in reduction of mnyo-inositol phosphates with adverse effects on mineral bioavailability has been achieved in comparison to the usual household procedure.     

Effect of soaking, germination, autoclaving and cooking on chemical and biological value of guar compared with faba bean

Raw, soaked, germinated, autoclaved and cooked both of guar and faba bean were chemically and biologically evaluated. Crude protein, crude fiber and ash contents of guar and faba bean decreased as a result of all treatments with the exception of protein content in both germinated guar and faba bean. A slight decrease in lipid content was noticed during germination, while there were no changes in lipids after soaking, autoclaving and cooking. Protein content of guar was higher than of faba bean, and showed higher values for all amino acids than faba bean protein except for lysine and tryptophan. Germination caused a slight increase in total essential amino acids, while soaking caused a slight decrease in both of guar and faba bean. There was a slight decrease in the mineral contents by the heat processes with the exception of Mg and Mn for guar and Na, Mn for faba bean due to the cooking process. Germinated guar and faba bean showed noticeable decrease in Na, K, Cu, Mn and Mg and a slight increase in Fe and Zn than the raw materials. Germination was more effective in reducing phytic acid than heat treatment, and therefore it improves the nutritional quality of both guar and faba bean. Protein efficiency ratio (PER), true digestibility (DT) and biological value (BV) were estimated in all treatments under study using rat bioassay procedures. Data revealed pronounced improvements of the nutritive value as a result of all processes under study especially germination being the most effective.     

Impact of pre-treatment (soaking or germination) on nutrient and anti-nutrient contents,cooking time and acceptability of cooked red dry bean (Phaseolus vulgaris L.) and chickpea (Cicer arietinum L.) grown in Ethiopia

Pulses are processed in diverse ways prior to consumption. Soaking and germination are among the most common traditional, household-level food processing strategies. This study was carried out to determine the effects of soaking, germination, cooking and their combinations on the contents of selected nutrients and anti-nutrients of red dry bean and chickpea. In addition, the effects of pre-treatment on cooking time and the acceptability of dishes prepared from red dry bean and chickpea were determined. The nutrient compositions (zinc, iron and calcium) of most soaked-cooked and germinated-cooked red dry bean and chickpea samples were not significantly different than those of respective controls. However, soaking and germination pre-treatments significantly lowered the phytate and tannin contents of the red dry bean and chickpea samples, with a few exceptions, and overall, polyphenol contents were lower after soaking-cooking than after germination-cooking. Most scores for sensory attributes of bean-based and chickpea-based dishes prepared from soaked or germinated samples were not significantly different than those of the controls. For most red dry bean and chickpea samples, longer germination times yielded superior results in terms of reductions in cooking time, tannin content, and phytate:zinc and phytate:iron molar ratio.     

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.     

Effect of processing on the nutrients and anti-nutrients of lima bean (Phaseolus lunatus L.) flour

The effect of soaking, autoclaving and toasting methods on the proximate and mineral composition and anti-nutrients of lima (butter) bean (Phaseolus lunatus L.) was investigated. The raw seed showed high content of proteins, lipids and ash with good values of K, Ca, Mg, P, Na and Fe in comparison with other legumes. Potassium was the most abundant macro mineral while sodium was the least. Iron content was the highest among the micro minerals. Manganese was not detected in any of the samples. Raw lima bean contained cyanide, trypsin inhibitor, lectin, phytin and tannin. Phytate phosphorus was calculated to be 28.2% of total phosphorus. There was no significantly different (P > 0.05) in the crude protein content of raw and processed flour. There was significant difference (P < 0.05) in the values of the macro and micro mineral. Soaking, autoclaving and toasting completely eliminated trypsin inhibitor and lectin while it significantly (P < 0.05) reduced the levels of phytin, tannin and cyanide. Except for tannin autoclaving for 20 min was found to eliminate all the other anti-nutrients in lima bean.     

Effect of processing on antinutrients and in vitro protein digestibility of kidney bean (Phaseolus vulgaris L.) varieties grown in East Africa

The effects of hydration, autoclaving, germination, cooking and their combinations, on the reduction/elimination of antinutrients, flatus-producing compounds and the improvement of in vitro protein digestibility of three selected Phaseolus vulgaris varieties were investigated. Reduction in the amount of total α-galactosides was attained by employing hydration process and was due to the differential solubility of the individual oligosaccharides and their diffusion rates. Due to their heat-sensitive nature, saponins, trypsin inhibitors and phytohaemagglutinins, diminished drastically to undetectable amounts when heating processes (cooking and autoclaving) were employed. Hydration and germination processes were less effective in reducing trypsin inhibitors, saponins and phytohaemagglutinins as compared with cooking/autoclaving processes. Germination process reduced stachyose, raffinose, phytic acid and tannins which was due to metabolic activity. The combination of germination followed by autoclaving processes yielded the most promising result in this study. The bean variety Roba exhibited better protein digestibility on processing and thus has high potential to be used as a raw material for the manufacturing of value-added products.