Antinutrients in amphidiploids (black gram × mung bean): varietal differences and effect of domestic processing and cooking

Phytic acid, saponin and polyphenol contents in grains of various varieties of black gram (Vigna mungo) Mung bean (Vigna radiata L.) amphidiploids ranged from 697 to 750, 2746 to 2972 and 702 to 783 mg/100 g, respectively. 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 the amphidiploid seeds. Soaking for 18 h removed 31 to 37% of the phytic acid; the extent of removal was higher with long periods of soaking. Saponins and polyphenols 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.     

Protein digestability of vegetables and field peas (Pisum sativum)

Protein digestibility was found to be 60.4 to 66.5 percent in raw unprocessed seeds of different pea cultivars. Protein digestibility (in vitro) was improved by the common methods of domestic processing and cooking including soaking, dehulling, ordinary cooking, pressure cooking and sprouting of legume grains. Pressure cooking had more pronounced effect on protein digestibility followed by ordinary cooking, sprouting, soaking for 18 h and (12 h) and dehulling. Pressure cooking of soaked and dehulled seeds was noticed to give most improved protein digestibility.     

Digestibility of proteins and starch (in vitro) of amphidiploids (black gram×mung bean) as affected by domestic processing and cooking

The effects of different domestic processing and cooking methods on starch digestibility (in vitro) and protein digestibility (in vitro) of four strains of amphidiploids (black gram×mung bean) were investigated. An increase of 35 to 48% and 22 to 25% was observed in starch digestibility and protein digestibility, respectively, when the seed of amphidiploids were soaked for 18 h. Cooking (both of unsoaked and soaked seeds) and germination improved significantly the starch digestibility and protein digestibility of all the varieties.     

Contents and digestibility of carbohydrates of mung beans (Vigna radiata L.) as affected by domestic processing and cooking

Effects of common processing and cooking methods on sugar and starch contents and starch digestibility (in vitro) of mung bean (Vigna radiata L.) were investigated. Soaking reduced the level of total soluble sugars, reducing sugars, non-reducing sugars and starch and improved starch digestibility, significantly. Cooking (both ordinary and pressure cooking) increased the concentrations of the sugars and digestibility of starch of soaked as well a unsoaked seeds. Starch contents, however, were decreased. Germination decreased starch thereby raising the level of the soluble sugars. Starch digetibility was increased appreciably.     

Effect of processing on the in vitro digestibility of proteins and carbohydrates in some Indian legumes

The effect of different types of processing such as boiling, pressure cooking, puffing, frying, germination, and germination followed by cooking on the protein and carbohydrate digestibility of chickpea, horsegram and cowpea were studied in in vitro systems. In the case of chickpea, the protein digestibility was not significantly improved by any of the treatments. However, for horsegram and cowpea, improvement in protein digestibility was observed after some of the different processing treatments. Frying decreased the protein digestibility in all of the pulses. All of the treatments, except germination, caused a marked increase in in vitro carbohydrate digestibility.     

Quality attributes of three new improved lines of Nigerian lima beans (Phaseolus lunatus L. Walp.)

Three promising new improved lines of lima beans (Tpl 1^B, Tpl 7^A and Tpl 175^A) were evaluated for physicochemical properties and cooking quality. The beans varied in seed dimensions and weights with Tpl 1^B and Tpl 7^A having smaller seed volume than Tpl 175^A. Seed coat percentages, leached solids and swelling capacities were within a range of 10.2–19.6% (w/w), 0.44–0.92 g/100 g and 94.0–121.0 g/100 g dry bean, respectively. Cooking times varied between 62 and 81 min without soaking and were reduced by about 34%following a presoaking treatment in water for 12 h at room temperature (28 ± 1 °C). Small seeds absorbed higher amounts of water during soaking and required more cooking time than larger seeds. No significant (p>0.05) difference in cooked texture was found between unsoaked beans cooked for 50 min and soaked beans cooked for 30 min,suggesting that cooking times and cooked texture for all lines were improved through soaking.     

Quick-cooking beans (Phaseolus vulgaris L.): I. Investigations on quality

Soaking three beans cultivars (Phaseolus vulgaris L.: Great Northern, kidney, and pinto) in mixed salt solution (sodium chloride 2.5% + sodium bicarbonate 1.5% + sodium tripolyphosphate 1.0% + sodium carbonate 0.5%) resulted in 80%–85% reduction in cooking time over corresponding controls. Irradiation (-rays) at 500 krads of soaked and dehydrated beans caused a reduction of nearly 50% in cooking time. Water uptake and leaching losses for each treatment during soaking at 22°, 37°, and 45°C were investigated. High temperature (37° and 45°C) and pH (9.0) caused greater water imbibition and total solid loss than at room temperature (22°C). Organoleptic evaluation revealed that quick-cooking Great Northern beans appear to be more acceptable than kidney and pinto beans. Quick-cooking cooked beans had better in vitro protein digestibility than conventionally cooked beans. Phenolic content was found to be inversely related to in vitro digestibility.Utah Agricultural Experiment Station Journal article no. 2481.     

Effects of Preharvest Sprouting on Flour Pasting Viscosity in Common Buckwheat (Fagopyrum esculentum Moench)

Abstract

Rain before harvest often causes buckwheat to sprout. Preharvest sprouting reduces the processing suitability of buckwheat flour. We examined the effects of preharvest sprouting on buckwheat flour quality by rapid visco-analysis (RVA) of milled sprouting grains of six buckwheat cultivars. Both artificial and natural rainfall increased the frequency of sprouting and decreased pasting viscosity. The difference in pasting viscosity between sprouting and non-sprouting buckwheat grains was not decreased by adding wheat flour. These results suggest that the mechanical characteristics of dough and boiled noodle may be affected by flour made from sprouting grains. Differing responses of the cultivars to rainfall indicate that higher pasting viscosity could be achieved by using cultivars that are resistant to preharvest sprouting caused by rain.     

Effect of domestic processing on zinc bioavailability from ricebean (Vigna umbellata) diets

The effects of various processing methods viz. pressure cooking with soaking, sprouting (48 h), sprouting and pressure cooking, dehulling, and pressure cooking of the dehulled legume on the bioavailability of zinc were studied. The total zinc content varied from 3.28 to 3.37%; the highestbeing in raw ricebeans and the lowest being in dehulled, soaked and pressure cooked, and sprouted and pressure cooked ricebeans, respectively. The soluble zinc content was highest for dehulled soaked and pressure cooked ricebeans (28.2%) and lowest for raw ricebeans (16.0%). The absorption, retention, and balance of zinc were estimated in rats fed experimental and standard ZnSO₄ diets using a balance study. The maximum retention of zinc wasobserved in dehulled soaked, and pressure cooked diets (63.37%) followed by sprouted (48 h) and pressure cooked (61.38%) diets. The gain in body weight, total femur zinc and retention of zinc in liver, kidneys and spleen were found to be highest for rats eating the sprouted pressure cooked diet followed by the dehulled, soaked and pressure cooked diet. Plasma zinc levels were found to range from 3.81 to 6.34 mol/dl; they were maximum for rats fed the dehulled, soaked and pressure cooked diet. It can be concluded that dehulling significantly improves the availability of zinc and germination of ricebeans is the best method to enhance the zinc availability.     

Changes in carbohydrate and nitrogenous components and amylase activities during germination of grain amaranth

Grain amaranth (Amaranthus hypochondriacus), Yercaud local variety, was soaked overnight and germinated for 192 h taking the soaked grains as the zero time (0 h) sample. The changes in the activities of - and -amylases, starch, sugar, protein and lysine contents during germination are reported. Activity of -amylase was high in the 0 h soaked grains, while -amylase activity was high in 72 h germinated grains. The joint action of the amylases resulted in a decrease of starch content from 0 to 192 h in germinated grains and an increase in total sugars during the initial period of germination.Protein nitrogen was found to decrease from 48 h to 192 h accompanied by an increase in free amino acid and non-protein nitrogen contents. Total lysine content was found to be increased by 31% in 24 h germinated grain amaranth. Protein fractionation of raw, soaked and 24 h germinated grain amaranth showed that the distribution of different types of proteins varied during germination of the grains. An increase of water soluble protein content was noticed in 24 h germinated grains.     

Effect of domestic processing on the cooking time,nutrients, antinutrients andin vitro Protein digestibility of the African yambean (Sphenostylis stenocarpa)

The effects of processing (soaking, dehulling, fermentation and heat treatment) on the cooking time, protien, mineral, tannin, phytate and in vitro protein digestibility (IVPD) of the african yambean (AYB) were examined. The cooking time ranged from 90–155 minutes. Soaking reduced cooking time by about 50 percent. Soaking for 12 hours was the most appropriate to reduce cooking time, tannin and phytate levels. It improved in vitro protein digestibility (IVPD). Prolonged soaking (24 hours) decreased calcium (Ca) and iron (Fe) values by 19 percent and 35 percent, respectively. Dehulling showed that Ca, Fe, magnesium (Mg) and zinc (Zn) were concentrated in the seed coat of the AYB. The seeds soaked and dehulled retained Mg and Zn. Dehulling reduced tannin but had no significant effect on phytate and the IVPD of the AYB except for seeds soaked for 12 hours before dehulling. Soaking for 24 hours before dehulling significantly increased crude protein content by 16 percent (p<0.05). Blanching and roasting increased the IVPD by 8–11 percent. Fermentation had no effect on the crude protein, Ca, Fe, Mg and Zn but significantly reduced phytate content of the AYB. Fermentation had no advantage over heat treatment with respect to improving the in vitro protein digestibility of the AYB.     

Biological utilization of vegetable peas: Effect of cooking and varietal differences

The flour of raw as well as cooked vegetable pea cultivars (Arkal and Bonneville) was used for biological evaluation of their protein quality. Cooking did not have a significant influence on the food intake. There were some differences in the food as well as protein intake and gain in body weights of rats when fed uncooked or cooked pea flour diets. Varietal differences did not seem to influence on apparent digestibility, true digestibility, biological value, net protein utilization and utilisable protein but cooking brought a significant (p<0.05) improvement in all of above mentioned parameters. Varietal differences as well as cooking exhibited no influence or serum protein concentration.     

Improvement in cooking quality of horse gram (Dolichos biflorus) by pre-soaking treatment with salt solution

Soaking of horse gram (Dolichos biflorus) in a solution of 1.5% NaHCO₃, 0.5% Na₂CO₃, and 0.75% citric acid for 12 h was found to be effective in reducing cooking time from 145 to 27 min. The treatment improved protein digestibility of cooked horse gram from 69 to 78%. Horse gram cooked after pre-treatment with soak solution had 35% less amount of polyphenols than that in untreated cooked samples. The suitability of this treatment for reducing cooking time of several other legumes was evaluated.     

Effect of a Bangladeshi home-cooking procedure on the amino acid content,trypsin inhibitor activity and in vitro digestibility of some legume seeds

Raw and cooked samples of cultivars ofLens esculenta (Lentils),Pisum sativum (peas),Phaseolus vulgaris (beans),Phaseolus aureus (navy beans)Cicer arietnum (gram), andLathyrus sativus (dhal) as well as precooked commercial products were analysed for amino acids, trypsin inhibitor activity and in vitro protein digestibility. Of the fifteen samples used in the study one lentil sample, one pea sample, two gram samples and one sample of khesari dhal were from Bangladesh, one gram sample was from Sri Lanka. The other samples were obtained either in shops in Norway or from an industrial firm. The latter were also obtained precooked and dried. The two samples obtained in shops were used with hull and dehulled.Neither cooking by a Bangladeshi household procedure nor industrial precooking and drying had any effect on the amino acid contents of the samples.Cooking and precooking reduced the trypsin inhibitor activity of the raw samples more when the original activity was high then when it was low. The inhibitor activity was similar between samples after cooking.Cooking and precooking and drying increased the in vitro protein digestibility in all samples except in the lentils in which the digestibility was reduced.In the raw samples protein digestibility was negatively correlated with the trypsin inhibitor activity.     

Changes in dietary fiber content and its composition as affected by processing of black beans (Phaseolus vulgaris,Tamazulapa variety)

This paper presents the effect that the traditional cooking process of black beans (Phaseolus vulgaris, Tamazulapa variety) has on the quantity and composition of soluble (SDF) and insoluble (IDF) dietary fiber of beans, as well as on its protein digestibility and protein quality. There was an increase of IDF from 18.1% in cooked beans to 22.4% in fried beans, and a decrease in SDF from 8.4% to 6.6%, respectively. Starch content decreased from 34.5% to 31.3%. No change was found in lignin. The xylose content was higher in IDF than in SDF and decreased to some extent from cooked to fried beans. Arabinose content was similar in IDF and SDF with no change caused by processing. The fraction containing glucose, mannose and galactose in IDF was higher than in SDF, the content increasing in IDF and decreasing in SDF, with processing. Protein content in IDF was higher than in SDF, with no major change when processing. About 29.5% of the total protein of beans was bound in DF. Protein digestibility and protein quality decreased from cooked to fried beans and was positively related to IDF.     

Relationship between total sulphur and sulphur amino acids in chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan [L.] Millsp.)

Total sulphur was determined in seed meal of 30 chickpea and 24 pigeonpea cultivars by the wet digestion procedure and by using the Leco sulphur analyser. Methionine and cystine were determined after performic acid oxidation in an amino acid analyser. The two methods used for total sulphur determinations were highly correlated (r=0.943). Percent meal protein was significantly correlated (r=0.476) with total sulphur in chickpea but not in the case of pigeonpea. Total sulphur content exhibited a significant positive correlation (r=0.651) with sulphur amino acids of pigeonpea when expressed as percent of protein but not in the case of chickpea. Correlation coefficients between total sulphur and sulphur amino acids when the results were expressed as percent of sample were positive for both chickpea (r=0.494) and pigeonpea (r=0.534). The amount of sulphur in methionine and cystine accounted for 54.8% of the total sulphur in chickpea and for 75.5% in pigeonpea. In both chickpea and pigeonpea, methionine was positively and significantly correlated with cystine when they were expressed either as percent of sample or as percent of protein.Submitted as J.A. no. 159 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).     

Influence of spices on utilization of sorghum and chickpea protein

Influence of eight common Indian spices on the protein quality of sorghum and chickpea was studied. Spices used include red chillies (Capsicum annum), black pepper (piper nigrum), coriander seeds (Coriandrum sativum) cumin seeds (Cuminum cyminum), garlic (Allium sativum), asafoetida (Ferula foetida), dry ginger (Zingiber officinale) and ajowan (Carum copticum). Addition of spices did not affect protein digestibility (TD) of sorghum. The BV of all sorghum diets with spices was higher than that of control diet. However, it was significant only in case of diets combined with red chilli + coriander (11) mix, black pepper + cumin (11) mix, coriander and cumin. Addition of spices did not have any effect on TD or BV of chickpea diets.     

In vitro starch and protein digestibility and iron availability in weaning foods as affected by processing methods

In the present investigation, four weaning foods were formulated using locally available cereals and pulses such as wheat (Triticum aestivum), barley (Hordeum vulgare) and green gram (Vigna radiata). Cereal, pulse and jaggery were used in the proportion of 70:30:25. Domestic processing technique like roasting and malting were used to process cereals and pulses for development of weaning foods. All the four blends had a nutrient composition within the range prescribed by the Indian Standard Institute (ISI) for processed weaning foods. The processing of grains resulted in 16–20% increase in starch digestibility and 17–32% increase in protein digestibility. Also 16–32% increase in iron availability was observed on processing. The effect was more remarkable in malted weaning foods as compared to roasted ones.     

Nixtamalized Flour From Quality Protein Maize (<Emphasis Type="Italic">Zea mays</Emphasis> L). Optimization of Alkaline Processing

Quality of maize proteins is poor, they are deficient in the essential amino acids lysine and tryptophan. Recently, in México were successfully developed nutritionally improved 26 new hybrids and cultivars called quality protein maize (QPM) which contain greater amounts of lysine and tryptophan. Alkaline cooking of maize with lime (nixtamalization) is the first step for producing several maize products (masa, tortillas, flours, snacks). Processors adjust nixtamalization variables based on experience. The objective of this work was to determine the best combination of nixtamalization process variables for producing nixtamalized maize flour (NMF) from QPM V-537 variety. Nixtamalization conditions were selected from factorial combinations of process variables: nixtamalization time (NT, 20–85 min), lime concentration (LC, 3.3–6.7 g Ca(OH)₂/l, in distilled water), and steep time (ST, 8–16 hours). Nixtamalization temperature and ratio of grain to cooking medium were 85 °C and 1:3 (w/v), respectively. At the end of each cooking treatment the steeping started for the required time. Steeping was finished by draining the cooking liquor (nejayote). Nixtamal (alkaline-cooked maize kernels) was washed with running tap water. Wet nixtamal was dried (24 hours, 55 °C) and milled to pass through 80-US mesh screen to obtain NMF. Response surface methodology (RSM) was applied as optimization technique, over four response variables: {In vitro} protein digestibility (PD), total color difference ( E), water absorption index (WAI), and pH. Predictive models for response variables were developed as a function of process variables. Conventional graphical method was applied to obtain maximum PD, WAI and minimum E, pH. Contour plots of each of the response variables were utilized applying superposition surface methodology, to obtain three contour plots for observation and selection of best combination of NT (31 min), LC (5.4 g Ca(OH)₂/l), and ST (8.1 hours) for producing optimized NMF from QPM.     

Effects of altitude above sea level on the cooking time and nutritional value of common beans

The present study was conducted with the objective to determine the effects of altitude above sea level, on the cooking time and nutritional value of common black beans (Phaseolus vulgaris). Three 100 g samples of theOstua variety were cooked at 8 individual locations, ranging in altitude from 0 to 2256 meters, in Guatemala, to establish water uptake and cooking time. The cooked samples were separated into cooked beans and cooking broth for chemical analysis. This included moisture, protein, lysine, tannins, total and enzyme susceptible starch, and fiber fractionation. The cooking liquor was analyzed for total solids, moisture, protein, ash and K. A 1200 g sample was cooked for the cooking time established previously, for biological testing of nutritional value,which included Net Protein Ratio (NPR), Protein Effciency Ratio (PER), and protein digestibility. Altitude influenced cooking time which increased from 78 min at 0 m, to 264 min at 2256 m. Final moisture content in the cooked bean was similar at all altitudes and there was a tendency to yield smaller amounts of solids in the cooking broth at higher altitudes. The increase in cooking time was significant. Bean water uptake at all times was significantly slower and smaller at ambient T, as compared to water uptake at boiling T, at all altitudes. Protein and lysine content were not affected by altitude, however, tannin and catechin were lower in cooked samples, as compared to the raw material. Altitude did not affect the content of these substances. Total starch and total sugars were higher in the raw sample, as compared to the cooked samples, but there was no effect of altitude. Enzyme susceptible starch (ESS) was lower in the raw sample as compared to the cooked samples, which contained similar amounts with respect to altitude. No change was observed in fiber fractions of the cooked beans. Likewise, the composition of the cooking broth was very similar between cooking locations. There was a small tendency to a lower protein quality, with respect to altitude, the effect of which was more obvious in the apparent protein digestibility values. Undercooking or overcooking at one location influenced protein quality values. The extended cooking time of beans at high altitudes, has important economic and environmental implications, since significant amounts of wood have to be used.