Physicochemical characterisation of mung bean (Phaseolus aureus) protein isolates

Protein isolates were prepared from mung bean (Phaseolus aureus) flour by two different methods, ie by traditional alkaline water extraction/isoelectric precipation and by micellisation, and studied with regard to chemical composition and protein fractional distribution. Micellisation decreased the phytic acid content, whereas the ‘isoelectrical’ isolate preparation resulted in an increase in phytic acid. Using size exclusion liquid chromatography (SE‐HPLC) and analytical ultracentrifugation, it has been shown that the major protein component in both isolates is a 7S globulin, which was most enriched in the micelle isolate. The results of one‐ and two‐dimensional SDS gel electrophoresis give evidence for the absence of interchain disulphide bonds in the polypeptide chains, which are typical for the 7S globulin class. The presence of minor protein zones corresponding to disulphide‐linked α and β chains of 11S globulin‐like storage proteins in the protein isolates has also been shown. © 2000 Society of Chemical Industry     

Interaction of Salmonella enterica subspecies enterica serovar Typhimurium and mung bean (Phaseolus aureus) plants

The effect of Salmonella enterica subspecies enterica serovar Typhimurium, a zoonotic serovar, on mung bean (Phaseolus aureus) cultivar Pant Mung-3 plants was studied. Inoculation of mung bean seeds with Salmonella Typhimurium (7.2 x 10(5) CFU/ml) reduced sprouting rate (P < 0.07). This effect was more pronounced at higher levels of contamination. In the soil inoculated with Salmonella Typhimurium (7.2 x 10(6) CFU/g), germination was retarded and the number of defective sprouts was also significantly higher (P < 0.002). Salmonella Typhimurium grew inside germinating seeds and plant tissues and persisted in seedlings, adult plants, and harvested seedlings dried and stored at room temperature (30 degrees C) up to 45 days. Phaseolus aureus plants grown in sterile soil was resistant to Salmonella Typhimurium infection at 15 days of age and cleared Salmonella from all the aerial parts within 3 h of infection. However, Salmonella Typhimurium could be reisolated from the basal area of the stem and from soil even after 45 days of exposure to the pathogen.     

The effect of processing on the texture of canned mung bean (Phaseolus aureus) shoots

The effect of various processing regimes on the pectic substances and the final texture of canned mung bean shoots has been studied. A blanching temperature of 75°C for 30 s was optimal in activating the native pectinesterase of the shoots and a holding temperature of 55°C for an optimal 30 min led to maximal deesterification of pectin. This treatment resulted in a canned product that was superior to a sample blanched at 100°C.; the addition of calcium ions did not improve the product.     

Nutritional quality of legume seeds as affected by some physical treatments 2. Antinutritional factors

Raw and treated cowpea, pea and kidney bean seeds were investigated for their content of antinutritional factors including tannins, phytic acid, trypsin inhibitors and oligosaccharides. Treatments applied included water soaking, boiling, roasting, microwave cooking, autoclaving, fermentation and micronization. Kidney bean contained the highest antinutrient content among all investigated seeds. The least tannins and phytic acid contents were recorded in Canadian cowpea while Canadian pea showed the lowest TIA. All treatments conducted caused significant decreases in tannins, phytic acid, TIA and oligosaccharides as compared to the raw seeds. Boiling caused the highest reduction in tannins followed by autoclaving and microwave cooking. Autoclaving and fermentation were the most effective in reducing phytic acid content. Heat treatments (boiling, roasting, microwave cooking and autoclaving) brought a total removal of trypsin inhibitors of all samples. Furthermore, autoclaving caused the highest reduction in oligosaccharides followed by fermentation while the least reductions were caused by either roasting or micronization with no significant difference between these two treatments.     

Nutrients and antinutritional factors in faba beans as affected by processing

 The influence on the nutrients content (soluble sugars, starch, dietary fibre and calcium) and antinutritional factors (α-galactosides and phytic acid) of faba beans (Vicia faba, L. major) of soaking in different solutions (distilled water, citric acid, and sodium bicarbonate solutions), cooking the presoaked seeds, dry-heating and germination have been studied. Soaking brought about a decrease in starch, sucrose, fructose, α-galactoside, dietary fibre and calcium content. Glucose was detected in soaked faba beans and soaking did not modify the phytic acid content. Cooking the presoaked faba beans produced a slight decrease in starch, and caused a general drop in α-galactosides, dietary fibre, calcium and phytic acid, with the exception of seeds presoaked in sodium bicarbonate in which cooking did not cause any appreciable changes in comparison with the unprocessed faba beans. Germination caused a sharp reduction in α-galactoside and phytic acid content after 6 days, whilst starch and dietary fibre decreased slightly. Calcium, however, enjoyed a slight increment during germination which was related to the decrease in the content of hemicellulose and phytic acid. Dry-heating caused a noticeable reduction in all the nutrients and antinutritional factors investigated. Of all the treatments studied, germination appears to be the best processing method to obtain nutritive faba bean flour, since it caused a minor decrease in starch content (15% loss), the largest α-galactoside and phytic acid removal (94% and 45%, respectively) and provided an appreciable amount of dietary fibre. Received: 21 December 1997 / Revised version: 19 February 1998     

Amino acid composition,mineral contents and protein solubility of some lima bean (Phaseolus lunatus l. Walp) seeds coat

Seeds coat of four lima beans (Phaseolus lunatus) varieties were subjected to standard analytical techniques in order to evaluate proximate, amino acid, mineral composition and protein solubility. The proximate analysis indicates moisture content in the range of (3.17–4.96%), crude protein (14.53–15.93%), fat (0.62–0.74%), crude fibre (32.59–33.59%), ash (2.43–3.88%), and carbohydrate (47.11–48.62%) on dry weight basis. The most abundant mineral element in the studied seeds coat was potassium 361.20–459.51 mg/100 g followed by sodium 71.27–102.51 mg/100 g and magnesium 83.20–95.23 mg/100 g. Calcium, phosphorus, iron and zinc were also present in significant amount while lead, cobalt and nickel were not detected. The amino acid profile demonstrates nutritionally acceptable results for the samples due to the high levels of essential amino acids in g/100 g protein such as lysine 6.42–7.41, leucine 7.51–8.37, arginine 4.42–7.02 and phenylalanine 5.01–5.49; when compared with FAO/WHO standard; with essential amino acids (TEAA) 49.47–51.07 g/100 g protein. Glutamic and aspartic acid were the most abundant amino acid in all the samples. The protein solubility profiles showed minimum values at pH 4 and more than 70% soluble at pH 10. The study has shown the potentials of lima bean seeds coat, an agro by-products in the development of new functional ingredients for food enrichment to provide an economic alternative raw material for food industries.     

Investigations of antinutritional factors of the winged bean (Psophocarpus tetragonolobus)

Twelve varieties of winged bean (Psophocarpus tetragonolobus) were analyzed for tannin, phytic acid, trypsin inhibitor, chymotrypsin inhibitor, α-amylase inhibitor and lectin. Tannin contents ranged from 1·35–6·75 mg/g of bean. Phytic acid contents ranged from 7·77–12·03 mg/g of bean and phytate-phosphorus represented a considerable percentage of the total phosphorus (44·3–54·8%). Chymotrypsin inhibitory activities were about twofold higher than trypsin inhibitory activities. α-amylase inhibitory activities could not be detected in any of the winged bean varieties used in this study. Hemagglutinating activities were observed with respect to all types of trypsinized human erythrocytes (A, B and O). However these activities disappeared completely after heating in a boiling water bath for 10 min.     

Nutritional and anti-nutritional characteristics of mucuna (Mucuna utilis) bean seeds

Some nutritional and anti-nutritional characteristics of mucuna (Mucuna utilis (Wight) Burck) bean seeds were studied. The mature seeds contained 264 g crude protein, 63 g crude fibre, 41 g crude fat, 37 g ash and 595 g carbohydrates kg^?1 DM. The essential amino acid profile compared well with the FAO/WHO scoring pattern except for a deficiency of sulphur-containing amino acids. Mineral composition was similar to those reported for most tropical grain legumes. Raw mucuna seed samples contained moderately high levels of anti-tryptic activity (2170 trypsin units inhibited g^?1 DM), but this was completely destroyed by cooking. The other anti-nutritional factors (phytate, cyanide and tannins) are probably of little nutritional significance provided that the beans are properly processed. The in-vitro protein digestibility of raw and cooked beans were 71·5 and 80·3 %, respectively. In view of the high L-DOPA contents reported in some mucuna cultivars, overconsumption of mucuna beans should be viewed with some caution until suitable processing methods are developed.     

Sensory evaluation and in vitro protein digestibility of mung bean as affected by cooking time

Heat treatment is particularly important in the preparation of mung bean for consumption, from the point of view not only of acceptability but also of improvement on protein digestibility. Sensory evaluation of cooked mung bean in terms of taste, colour, aroma and texture has an organoleptic panel indicated that there was no significant difference (P < 0.05) between mung bean cooked for 25, 30, 35, 40 and 45 min. An in vitro protein digestibility assay was used to examine the effect of cooking time on protein digestibility. The applied non-linear mathematical model indicated a high correlation coefficient between experimental and predicted data (R² ≥ 0.999). A maximum improvement in in vitro protein digestibility (IVPD) of 4.83% was obtained by cooking for 38.6 min. No remarkable changes in most amino acids were found between raw and cooked samples except that tryptophan was decreased by 4.69% and a 10.29% loss of threonine occurred with the optimum cooking time. © 1999 Society of Chemical Industry     

Evaluation of the amino acid content and sensory value of flageolet bean seeds (Phaseolus vulgaris L.) as affected by preprocessing methods before freezing

The aim of the work was to evaluate the content of amino acids in flageolet bean seeds, prepared for consumption from frozen products obtained using different methods. One of the frozen products was obtained using the traditional method (blanching–freezing–frozen storage) and then cooked. The other was obtained using the modified technology (cooking–freezing–frozen storage), followed by defrosting and heating in a microwave oven. The culinary and technological processing applied brought about a pronounced decrease in tyrosine content (35–47% in 16 g N). The content of the remaining amino acids decreased or increased in relation to the raw material within the extremes of ?15% to +17%. Sulphur amino acid was the limiting amino acid. Product obtained using traditional method had the higher quality protein (EAA index 144–166) of seeds prepared for consumption. In sensory test products, blanched before freezing were evaluated a bit higher than those cooked before freezing (ready‐to‐eat).     

Assessment of nutritional compounds and antinutritional factors in pea (Pisum sativum) seeds

The nutrient and antinutritional factor content of 18 pea lines was studied. The following levels were found: non‐protein nitrogen 5.2–10.2 g kg^?1 DM, protein nitrogen 35.3–42.4 g kg^?1 DM, lysine 50.7–76.3 g kg^?1 protein DM, histidine 17.8–24.8 g kg^?1 protein DM, tyrosine 22.6–30.0 g kg^?1 protein DM, protein 25.9–31.9% DM, in vitro protein digestibility 89.3–95.6%, vitamin B₁ 5.9–10.3 mg kg^?1 DM, vitamin B₂ 1.1–3.7 mg kg^?1 DM, sucrose 11.6–25.4 g kg^?1 DM, raffinose 4.1–10.3 g kg^?1 DM, stachyose 10.7–26.7 g kg^?1 DM, verbascose 0.0–26.7 g kg^?1 DM, total α‐galactosides 22.6–63.4 g kg^?1 DM, trypsin inhibitor activity 0.8–8.4 TIU mg^?1 DM, inositol hexaphosphate 2.3–6.5 g kg^?1 DM, inositol pentaphosphate 0.1–1.8 g kg^?1 DM and total inositol phosphates 2.8–7.1 g kg^?1 DM. Peas with yellow cotyledons had the highest trypsin inhibitor activities, those with light green cotyledons had the highest lysine contents, and those with dark green cotyledons were the richest in vitamins B₁ and B₂. Peas with brown testae had the lowest verbascose and sucrose contents, while they were the richest in inositol hexaphosphate. Smaller peas were characterised by the highest protein nitrogen contents as well as the highest contents of vitamins B₁ and B₂, verbascose and inositol pentaphosphate. Peas of medium size showed the lowest verbascose, α‐galactoside and vitamin B₂ contents. Bigger peas showed the lowest inositol pentaphosphate contents. © 2003 Society of Chemical Industry     

Nutritional response of mature rats to kidney bean (Phaseolus vulgaris) lectins

In a series of 10-day pair feeding experiments it was found that the nutritional value of diets containing beans was essentially the same for rats aged between 30 and 123 days. Thus net protein utilisation (NPU) values of 25–39 on diets containing Processor bean (35 g protein kg^?1) + egg albumin (65g protein kg^?1) were obtained. As food intakes were considerably reduced when rats were fed diets containing more than 35g protein kg^?1 of Processor bean, the measurement of protein utilisation became increasingly more difficult. The severe disruption of the brush borders of duodenal and jejunal enterocytes, originally observed when bean-containing diets were fed to young (30-day-old) rats was also found with rats up to the age of 120 days on similar diets. Similarly, the development of circulating anti-lectin antibodies in the animals showed no age dependence within the age limits investigated. It was also shown that oral immunisation did not protect the rats from the effects of toxicity and that the immune response was a result of continuous absorption of lectin throughout the feeding period. Thus the extent and the mechanism of toxicity of Phaseolus vulgaris bean lectins were found not to be dependent on the age or maturity of the animal.     

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 ionizing radiation on antinutritional features of velvet bean seeds (Mucuna pruriens)

Impact of gamma irradiation on the antinutritional constituents of seeds of Mucuna pruriens was assessed on exposing to doses of 2.5, 5.0, 7.5, 10, 15 and 30 kGy. Except for 2.5 kGy, the rest showed significant dose-dependent increase in phenolics. Tannin concentration did not differ significantly up to 7.5 kGy, while it significantly increased at higher doses. Excluding 2.5 kGy, the rest of the treatments showed significant decreases in the phytic acid and complete degradation was attained at 15 and 30 kGy. The l-DOPA concentration showed a dose-dependent decline. A trace amount of hemagglutination activity was seen on human erythrocytes in raw seeds, which was completely absent on irradiation (>5 kGy). Concentration of Polonium-210, a natural radionuclide falls within the admissible limits for consumption. As Mucuna seeds serve as food, feed or as pharmaceuticals, it may be necessary to set the ionizing radiation to a specific dose to retain optimum levels or to eliminate phenolics, tannins, phytic acid and L-DOPA. As irradiation is a physical and cold process, it may be ideal and emerge as an important technique to improve the nutritional or pharmaceutical quality of Mucuna seeds and its products.     

Physicochemical properties and in vitro digestibility of resistant starch from mung bean (Phaseolus radiatus) starch

RS from mung bean starch was prepared by autoclaving, pullulanase debranching, and retrogradation. Physicochemical properties, crystalline structure, and in vitro digestibility of selected RS samples with different RS content were investigated. Compared to native starch, AAM content of RS increased but MW decreased greatly. SEM clearly showed RS samples exhibited irregular shaped fragments with compact structure. XRD pattern indicated that RS samples had typical B‐type pattern with sharp peaks at 17.0°, 22.2°, and 23.9° 2θ. The relative crystallinity, gelatinization temperatures, and enthalpy increased with increasing RS content. The α‐amylase digestibility of RS was lower than that of native starch. The results suggested that the decrease in enzymatic digestion of RS might due to compact and ordered crystalline structures after debranching and recrystallization.     

Structural and some nutritional characteristics of Velvet bean (Mucuna pruriens) and Lima bean (Phaseolus lunatus) starches

Velvet bean (Mucuna pruriens) and lima bean (Phaseolus lunatus) starches were isolated from seeds and their structural characteristics evaluated using XRD, size‐exclusion chromatography and light scattering analyzes. Total starch, available starch, RS and in vitro digestibility were also determined. Structural and nutritional characteristics of Velvet bean and Lima bean starches were compared to those of commercial corn starch. The legumes starches presented a C‐type XRD pattern and crystallite sizes of 43.1 Å for velvet bean and 48.3 Å for lima bean. Lima bean starch average molar mass (4.9 × 10⁶ g/mol) was slightly higher than the velvet bean starch (3.04 × 10⁶ g/mol). Size‐exclusion chromatography indicated structural similarity between the lima bean and corn starches which differed from that of the velvet bean starch. Hydrodynamic radius (R_H) for the velvet bean and lima bean starches was 45.5 and 55 nm, respectively, and their radius of gyration (R_G) was 67.7 and 82.5 nm, respectively. Total starch content in all three starches was greater than 98%. Their complex crystalline structure provided the legume starches lower in vitro digestibility values than the corn starch. RS content in both the velvet bean starch (7.72%) and lima bean starch (5.66%) was higher than in the corn starch, essentially qualifying these polysaccharides as natural dietary fiber sources, with the associated physiologic advantages.     

Amino acid composition of seed meals of yam bean (Sphenostylis stenocarpa) and lima bean (Phaseolus lunatus)

The amino acid compositions of the seed meals of four varieties of yam bean and one variety of lima bean have been compared with the F.A.O.¹ standard.     

Proteolytic breakdown of kidney bean (Phaseolus vulgaris) storage proteins: Nutritional implications

Glycoprotein II, the major storage protein of the seeds of kidney bean (Phaseolus vulgaris), was largely resistant to hydrolysis by pure gut endopeptidases. However, the protein was extensively digested in vitro and nearly 90% of it became soluble in 5% trichloroacetic acid by treatments first with extracts of rat stomach followed by intestinal contents or alternatively first with pepsin, followed by pancreatin. Heat denaturation (100°C for 10 min) had no appreciable effect on the digestion. A similarly high extent (between 80 and 90%) and rate of digestion of pure Glycoprotein II was observed in vivo. However, intubation of pure Glycoprotein II into the stomach of previously fasted rats increased the production of insoluble intestinal secretions containing relatively large amounts of nitrogen. As this N passed into the caecum, it reduced both the apparent digestibility of Glycoprotein II and the net gain of N for the animal. Moreover, in the presence of a mixture of raw bean proteins in the stomach of rats the time taken to empty its content into the intestine was increased appreciably. Additionally, the toxic effects of the lectins in these mixtures, particularly on continuous feeding, were observed.     

Effect of ochratoxin A on some biochemical changes in seeds of mung bean (Vigna radiata,var Pusa 119

The effect has been studied of a range of concentrations of ochratoxin A on some biochemical parameters, viz chlorophyll, protein and nucleic acid concentrations during seed germination and seedling growth in mung beans (Vigna radiata (L) Wilczek, var Pusa 119). Reduction in levels of all the parameters resulted from ochratoxin A treatment, and the extent of reduction was directly influenced by the concentration of toxin applied.     

In vitro availability of minerals of some tropical and citrus fruits as influenced by antinutritional factors

Four tropical fruits and three citrus fruits were analyzed for moisture, ash, antinutritional factors (phytate, oxalate, and polyphenols) contents, and total and available minerals. Moisture contents ranged from 6.0 to 83.17% for tropical fruits while that of citrus fruits ranged from 88.20 to 89.50%. Ash contents ranged from 2.56 to 4.50% and from 3.83 to 4.83%, for tropical and citrus fruits, respectively. All fruits contained no oxalate while phytate and polyphenols ranged from 48.1 to 134.1 mg/ 100 g and from 0.115 to 0.34%, respectively. For all fruits major minerals contents ranged from 7.7 to 433.3 while trace ones ranged from 0.116 to 1.91 mg/100 g. In vitro availabilities of major minerals (% of total) varied from 11.1 to 86.2% while for minor ones it ranged from 13 to 72.5%.