Rice Bean Research Articles

Exudation of Amino Acids and Sugars from Imbibing Seeds of Several Leguminous Crops.

Exudation from imbibing seeds is an indicator of seed vigor and influences seedling emergence. The objective of this report was to determine the substance of exudation from the seeds and its differences among crops and cultivars. The amounts of amino acids and sugars exuded from the imbibing seeds of 66 cultivars in 8 leguminous crops were measured by HPLC. Sixteen amino acids were detected from the seeds in soybean, and 14 in kidney bean. Only two were detected from the seeds in rice bean. The amount of exudates was greatest in soybean (1020μg per gram seed), and least in rice bean (71μg per gram seed). Arginin exuded in high frequency, however, it accounted for 32%(kidney bean)to 80% (rice bean) of total amino acid exudation. The sugars exuded from the seeds were mostly fructose and glucose. The frequency of sugar exudation was high in soybean and kidney bean, but low in mung bean and rice bean, and no detection in black gram. A great deal of exudates was found in soybean(2065μg per gram seed)and kidney bean(1297μg per gram seed). It doubled the amount of amino acids exuded in these two crops. No correlation between the exudation of full seeds and crushed seeds indicated that the exudation is independent of the contents of exudates in the seed. Dramatic difference was found among 29 cultivars in soybean, since the exudation presented from no detection to the greatest deal of exudation in some cultivars. Furthermore, the large seeds were very likely easy to exude, but no significant correlation was found between exudation and thickness of seedcoat.

Comparative molecular mapping in Ceratotropis species using an interspecific cross between azuki bean (Vigna angularis) and rice bean (V. umbellata)

A genetic linkage map was developed with 86 F2 plants derived from an interspecific cross between azuki bean (Vigna angularis, 2n=2x=22) and rice bean (V. umbellata, 2n=2x=22). In total, 14 linkage groups, each containing more than 4 markers, were constructed with one phenotypic, 114 RFLP and 74 RAPD markers. The total map size was 1702 cM, and the average distance between markers was 9.7 cM. The loci showing significant deviation from the expected ratio clustered in several linkage groups. Most of the skewed loci were due to the predominance of rice bean alleles. The azuki-rice bean linkage map was compared with other available maps of Vigna species in subgenus Ceratotropis. Based on the lineage of the common mapped markers, 7 and 16 conserved linkage blocks were found in the interspecific map of azuki bean ×V. nakashimae and mungbean map, respectively. Although the present map is not fully saturated, it may facilitate gene tagging, QTL mapping and further useful gene transfer for azuki bean breeding.

Testing Iron and Zinc Bioavailability in Genetically Enriched Beans (Phaseolus Vulgaris L.) and Rice (Oryza Sativa L.) in a Rat Model

A rat model was used to determine the bioavailability of iron and zinc in bean seeds and rice grain from enriched genotypes of these globally important staple foods. Seed and grain from the genotypes tested (intrinsically radiolabelled with either 59Fe or 65Zn) were cooked, homogenized in water, and lyophilized to dryness. The dried, radiolabelled powder was fed to young male rats in single meals. Bioavailability was calculated from the amount of radiolabelled iron and zinc retained in the rats over a 10-day period as determined each day by whole-body gamma spectrometry assay. The data collected demonstrate that increasing the amount of iron or zinc in enriched rice grain and bean seed significantly increases the amount of iron or zinc bioavailable to rats. Although a rat model is not ideal for determining iron and zinc bioavailability to humans, because rats are much more efficient at absorbing iron and zinc from plant foods than humans, rats can be used to give relative estimates of bioavailable iron and zinc in plant foods. These estimates can be used to rank promising genotypes of staple foods for use in later feeding trials with humans, greatly reducing the numbers of genotypes that would have to be tested in humans without use of the rat model. Ultimately, because of the complexities of determining the bioavailability to humans of iron and zinc in plant foods, human feeding trials performed under free-living conditions should be conducted with the most promising genotypes before these genotypes are released for distribution to breeding programmes worldwide

Chemical composition, antinutritional factors and effect of cooking on nutritional quality of rice bean [Vigna umbellata (Thunb; Ohwi and Ohashi)

The mature seeds of four cultivars of rice bean [Vigna umbellata (Thunb; Ohwi and Ohashi)] were analysed for some nutritional and antinutritional factors. The cultivars showed little variation in their chemical composition. On a dry matter basis, the percentage of crude protein varied from 16.9 to 18; crude fat 0.46 to 0.52, crude fibre 6.3 to 7.5, total soluble sugar 4.9 to 5.6, starch 52.2 to 55 and ash 4.2 to 4.4. The amounts (mg/100 g) of calcium ranged from 280 to 325, sodium 43 to 52, potassium 171 to 210, phosphorus 216 to 275 and iron 6 to 7, respectively. The cultivars had trypsin inhibiting activities (TIA) of 2456 to 2534 TIU g−1 phytic acid 1976 to 2170 mg per 100 g and tannins 513 to 572 mg per 100 g, respectively. Two cooking treatments, namely, 15 min pressure cooking (15 MPC) and 50 min boiling (50 MB) showed a considerable decrease in antinutritional factors.

The nolL Gene from Rhizobium etli Determines Nodulation Efficiency by Mediating the Acetylation of the Fucosyl Residue in the Nodulation Factor

The nodulation factors (Nod factors) of Rhizobium etli and R. loti carry a 4-O-acetyl-L-fucosyl group at the reducing end. It has been claimed, based on sequence analysis, that NolL from R. loti participates in the 4-O-acetylation of the fucosyl residue of the Nod factors, as an acetyl-transferase (D. B. Scott, C. A. Young, J. M. Collins-Emerson, E. A. Terzaghi, E. S. Rockman, P. A. Lewis, and C. E. Pankhurst. Mol. Plant-Microbe Interact. 9:187-197, 1996). Further support for this hypothesis was obtained by studying the production of Nod factors in an R. etli nolL::Km mutant. Chromatographic and mass spectrometry analysis of the Nod factors produced by this strain showed that they lack the acetyl-fucosyl substituent, having a fucosyl group instead. Acetyl-fucosylation was restored upon complementation with a wild-type nolL gene. These results indicate that the nolL gene determines 4-O-acetylation of the fucosyl residue in Nod factors. Analysis of the predicted NolL polypeptide suggests a transmembranal location and that it belongs to the family of integral membrane transacylases (J. M. Slauch, A. A. Lee, M. J. Mahan, and J. J. Mekalanos. J. Bacteriol. 178:5904-5909, 1996). NolL from R. loti was also proposed to function as a transporter; our results show that NolL does not determine a differential secretion of Nod factors from the cell. We also performed plant assays that indicate that acetylation of the fucose conditions efficient nodulation by R. etli of some Phaseolus vulgaris cultivars, as well as of an alternate host (Vigna umbellata).

Effects of the physico-chemical properties of three legume fibers on cholesterol absorption in hamsters

The effects of the insoluble dietary fibers (IDFs) prepared from Phaseolus angularis, Phaseolus calcaratus, and Dolichos lablab seeds relative to cellulose as control on cholesterol absorption in hamsters were studied. Test diets which contained 5% of cellulose and the three legume IDFs as the sole source of dietary fiber were fed to male Golden Syrian hamsters for 30 days. Compared to the control diet, all three legume IDF diets significantly ( P < 0.05) lowered the levels of serum LDL cholesterol as well as liver cholesterol, but only P. calcaratus IDF diet significantly reduced ( P < 0.05) the serum total cholesterol. Moreover, D. lablab IDF diet diet led to a significantly ( P < 0.05) higher level of HDL cholesterol relative to the control. In this study, all three legume IDF diets were found to give a significantly ( P < 0.05) higher values of HDL:total cholesterol ratios. Linear correlations were observed between the HDL:total cholesterol ratio and the bulk density, water-holding capacity (WHC), and cation-exchange capacity of the legume IDFs ( r = −0.99, 1.00, and 0.95, respectively, P < 0.05). The cholesterol-lowering effects of the three legume IDFs relative to cellulose might partially be due to their indirect influences on lowering the intestinal absorption of cholesterol caused by the above physico-chemical properties.

Purification and Characterization of Protease Inhibitor from Rice Bean (Vigna umbellata T.) Seeds

A Protease inhibitor from seeds of rice bean has been purified to apparent homogeneity as judged by native-PAGE with about 29% recovery using ammonium sulfate fractionation, ion exchange chromatography on DEAE-cellulose, and gel filtration through Sephadex G-100. The purified preparation with molecular weight of 16.8 kD was found to be a monomer as revealed by SDS-PAGE under reducing and non-reducing conditions. The purified inhibitor in solution was stable upto 40°C. However, it lost its activity gradually and was completely inactive when heated at 100°C for 2 h and 125°C for 1 h. Heating at 125°C changed the conformation of the inhibitor as was evident from the altered UV spectrum compared to that of native. It had two pH optima at pH 6.0 and at 10.0 and was stable over a wide range of pH (pH 3.0 to 10.0). It lost its activity on exposure to 2-mercaptoethanol, indicating the role of S-S linkages in maintaining the three dimensional structure of the protein inhibitor. The inhibitor was completely inactive towards papain, while it inhibited pepsin only slightly. Trypsin and chymotrypsin were inhibited upto the extent of 60% and 30%, respectively. Trypsin inhibition was of non-competitive type with dissociation constant for the enzyme-inhibitor complex in the region of 2.07 mg ml-1. The rice bean inhibitor appears to be of Bowman-Birk type as it has molecular weight lower than that generally observed for Kunitz type inhibitors and seems to be double headed - a characteristic specific of Bowman - Birk type inhibitor.

ISOLATION OF MUTANTS AND THEIR FREQUENCIES UNDER M2 GENERATION IN RICE BEAN (Vigna umbellata L. THUMB)

Two varieties of rice bean (Vigna umbellata) cv. RBL-50 and L-1 were treated with gamma rays (50,60, 70, 80 and 90 KR), EMS (0.3, 0.4, 0.5 0.6 and 0.7%) and combination of gamma and EMS (30KR+ 0.2%, 40KR + 0.2%, 30KR+0.3% and 40KR+0.3%). Among the varieties, L-1 and among the mutagens, gamma rays induced more number of chlorophyll and viable mutants. The viridis types were predominent than albinia, xantha and chlorina types, irrespective of the variety. The gamma doses of 60KR in RBL-50; 50KR, 90KR in L-1 and among the EMS treatments 0.5, 0.6 per cent in RBL-50; 50 KR, 90KR in L-1 were considered the best doses/concentrations, based on mutagenic effectiveness and efficacy. Twelve types of viable mutants were observed with abnormal leaves and coloured seeds being prominent among them. In the variety L-1, the doses/concentrations which have brought out highest chlorophyll mutations, also brought out highest viable mutations.

Retenção de nitrato num solo de carga variável, influenciada por adubação fosfatada e calagem

O presente trabalho teve como objetivo avaliar o efeito da aplicação de fósforo e de calcário sobre a capacidade de retenção de nitrato (CRN) de um solo de carga variável. Entre 1982 e 1989, um Latossolo Vermelho-Escuro argiloso de cerrado foi cultivado com milho, trigo, arroz e feijão (2, 4, 5 e 6 cultivos, respectivamente), recebendo adubação fosfatada (total de 1530 kg/ha de P2O5: 90 kg/ha por cultivo) ou adubação fosfatada+calagem (5,5 t/ha de calcário dolomítico: 2,5 e 3,0 t/ha em 1982 e 1985, respectivamente). Testes realizados em amostras coletadas em 1991 mostraram que o solo apresentava CRN negativa (exclusão do nitrato) na camada arável (0-20 cm), e positiva e crescente com a profundidade, nas camadas subjacentes. Os tratamentos diminuíram a CRN original do solo na camada de 20-60 cm, sendo esse efeito mais intenso no tratamento com calagem. A adubação fosfatada e, especialmente, a calagem, exerceram considerável efeito residual sobre a capacidade de retenção de nitrato do latossolo estudado.

Hypocholesterolemic Effects of Protein Concentrates from Three Chinese Indigenous Legume Seeds

The hypocholesterolemic effect of the protein concentrates (PCs) prepared from Phaseolus angularis, Phaseolus calcaratus, and Dolichos lablab seeds relative to that of casein were studied in hamsters. Male Golden Syrian hamsters were fed test diets containing these proteins at 12% level for 30 days. As compared with casein, the three legume PCs produced significantly lower (p < 0.05) levels of triglyceride and total and low-density lipoprotein cholesterol in the blood serum as well as lower liver total lipids and cholesterol contents, except that P. angularis PC gave a only nonsignificantly slight decrease in the serum total cholesterol. Moreover, only the PC of P. calcaratus gave a significantly higher (p < 0.05) level of serum high-density lipoprotein cholesterol. Generally, the PCs of P. calcaratus and D. lablab seemed to be more potent at lowering raised serum cholesterol levels than that of P. angularis. Keywords: Phaseolus angularis; Phaseolus calcaratus; Dolichos lablab; protein concentrate; hypoch...

Nutritional assessment of three Chinese indigenous legumes in growing rats

The nutritional values of three under-utilized Chinese indigenous legumes, Phaseolus angularis, Phaseolus calcaratus and Dolichos lablab, were evaluated by animal feeding. The nutritional values of the legumes were determined by comparing the food intake, protein intake, weight of carcass, protein efficiency ratio (PER), net protein ratio (NPR) and true protein digestibility (TD) of the legume-based diets with those of the casein control diet. Although the PER (ranged 2.41 to 4.11), NPR (ranged 6.15 to 6.74), and TD (ranged 70.1 to 75.8%) of these three legume seeds were significantly lower than those of the casein control, they were comparable to those of the other common known legumes. Besides, the growth performance were assessed by determining the weight of some organs in rats such as livers, kidneys, spleens and caecum. All three legumes had no effect on the weight of livers but their effect on the weight of kidneys, caecum and spleens varied.

Growth and Yield Response of Rice Bean (Vigna umbellata) Fodder to Different Levels of N and p

Growth and Yield Response of Rice Bean (Vigna umbellata) Fodder to Different Levels of N and p

Rice and common bean growth and nutrient concentration as influenced by aluminum on an acid lowland soil

Aluminum (Al) toxicity is a major limiting factor for crop production in many acid soils in Brazil. Two greenhouse experiments were conducted to evaluate response of rice (Oryza saliva L.) and common bean (Phaseolus vulgaris L.) to Al levels on a Low Humic Gley acid soil. The Al levels created by liming were: 0,0.03, 0.10, 0.23, 1.03, and 3.83 cmolc kg‐1 of soil. Rice dry matter and grain yield were significantly improved (P<0.05) with increasing Al levels in the soil solution. However, common bean dry matter as well as grain yield were significantly (P<0.01) decreased with increasing Al levels. At 3.83 cmolc Al kg‐1 of soil, bean did not produce any dry matter or grain yield. On an average, Al decreased nutrient concentrations in the tops of rice plant except zinc (Zn) and manganese (Mn), but in bean crop almost all the nutrients concentrations were increased with increasing Al levels. Rice showed tolerance to Al toxicity, whereas, common bean was susceptible to toxicity of this element. For successful intensive crops production lime application will be necessary in Varzea soils especially for legume production.

Functional properties of flours prepared from three Chinese indigenous legume seeds

The functional properties of Phaseolus angularis, Phaseolus calcaratus and Dolichos lablab flours were investigated and compared with those of soybean flour. The minimum nitrogen solubilities of P. angularis and P. calcaratus flours were at pH 5 while that of D. lablab flour was at pH 4. Compared with soybean flour, P. angularis, P calcaratus and D. lablab flours exhibited lower foam capacities, water- and oil-holding capacities, but higher gelation capacities. The emulsifying activities and emulsion stabilities of all legume flours tested were pH-dependent with minimum values at pH 4. Their emulsion stabilities were greater than 80.2% from pH 2 to 10, except at pH 4. Foam capacities and stabilities were also pH-dependent, highest foam stabilities being at pH 4.

Chemical composition of three underutilized legume seeds grown in China

Proteins of Phaseolus angularis, Phaseolus calcaratus and Dolichos lablab seeds (24.9 to 26.5% dry weight) were mainly contributed by their cotyledons which had a proportion of 82.9 to 90.8% by weight of the whole seeds. The levels of all the essential amino acids of the legume seeds (415 to 443 mg g −1 protein) were above the FAO/WHO, (1990) requirement with the essential amino acid scores of the methionine and cystine being 1.02 to 1.19. Appreciable amounts of oligosaccharides of the raffinose family were found mainly in the cotyledons (3.52 to 4.72% dry weight). The total dietary fibre of the legume seeds (13.5 to 19.3% dry weight) consisted predominantly of insoluble dietary fibre (IDF). The cotyledons contained 45.9 to 51.4% dry weight of starch but had low contents of cellulose and lignin. Hulls were highly lignified and consisted predominantly of IDF, with values ranging from 70.7 to 74.0% dry weight. The principal sugar residue analysis revealed that pectins were the major polysaccharide present in the SDF of both the cotyledons and the hulls. While xylans and cellulose were the major polysaccharides present in the IDF of the hulls, xyloglucans and arabinose-rich pectic substances were the principal non-starch polysaccharides in the IDF of the cotyledons.

Separation, characterization, and specificity of alpha-mannosidases from Vigna umbellata.

Information about the specificity of glycosidase enzymes is important since it affects their use for characterization and synthesis of oligosaccharides. Two alpha-mannosidases (EC 3.2.1.24), I and II, were isolated from rice beans (Vigna umbellata). The native molecular weight of both isozymes was estimated to be 329,000, but pIs of form I were 5.03-5.34 and pIs of form II were 5.46-6.20. The two isozymes were characterized in terms of optimal pH and temperature, effects of metal ions, inhibition by swainsonine and 1-deoxymannojirimycin, and kinetic parameters for p-nitrophenyl-alpha-D-mannopyranoside and Man alpha (1-2)Man. Both enzymes were more specific towards Man alpha (1-2)Man in both hydrolysis and synthesis, but their hydrolytic specificities towards Man alpha (1-3)[Man alpha (1-6)]Man were different.

Changes in the Dietary Fiber (Resistant Starch and Nonstarch Polysaccharides) Content of Cooked Flours Prepared from Three Chinese Indigenous Legume Seeds.

The effects of cooking on the dietary fiber (DF) content, which included resistant starch (RS) and nonstarch polysaccharides (NSP), of flours from Phaseolusangularis, Phaseolus calcaratus, and Dolichos lablab seeds, indigenous to China, were evaluated. The cooked legume flours were prepared by milling boiled and freeze-dried legume whole seeds. Total DF contents of all cooked flours were higher than those of the raw ones. The results showed an increase of NSP and RS to various extents with increasing cooking time of the flours. In the NSP of the legume flours, both the soluble and insoluble fractions increased during cooking, and a redistribution of the soluble and insoluble NSP components was observed. Generally, cooking increased the solubilization of the NSP in the legume seed flours, which might be important for their use as soup ingredients for therapeutic purposes. The increase of RS in the legume flours could be mainly due to the presence of cell-enclosed starch and retrograded starch formed during cooking. Such increase in the RS content of the cooked legume flours might have beneficial physiological effects for humans.

Effects of cooking on content of amino acids and antinutrients in three Chinese indigenous legume seeds

The effects of domestic cooking on the content of amino acids and antinutrients of Phaseolus angularis, Phaseolus calcaratus and Dolichos lablab seeds were evaluated. Heat treatment (30 min) caused significant declines (P<0·05) in the apparent recovery of most of the essential amino acids except leucine and phenylalanine for P angularis, and except phenylalanine for P calcaratus. Cooking D lablab seeds (60 min) also resulted in a significant reduction (P<0·05) in the apparent recovery of all the essential amino acids except leucine, histidine, lysine and threonine. Increased cooking time for P angularis (60 min), P calcaratus (60 min) and D lablab (120 min) led to a lower apparent recovery of methionine (28·9–31·6%) and cystine (17·1–19·3%). Even with increased cooking times, the total essential amino acid levels in all three cooked seeds remained higher than that of the FAO/WHO requirement, except for methionine and cystine. Cooking (60 min) was found to be effective in reducing the tannin contents of P angularis, P calcaratus and D lablab seeds by 70·6, 64·6 and 74·6%, respectively. Upon cooking, phytate and trypsin inhibitory activity in different seeds were also reduced to different extents depending on the cooking times. ©1997 SCI

Effects of cooking on content of amino acids and antinutrients in three Chinese indigenous legume seeds

The effects of domestic cooking on the content of amino acids and antinutrients of Phaseolus angularis, Phaseolus calcaratus and Dolichos lablab seeds were evaluated. Heat treatment (30 min) caused significant declines (P<0·05) in the apparent recovery of most of the essential amino acids except leucine and phenylalanine for P angularis, and except phenylalanine for P calcaratus. Cooking D lablab seeds (60 min) also resulted in a significant reduction (P<0·05) in the apparent recovery of all the essential amino acids except leucine, histidine, lysine and threonine. Increased cooking time for P angularis (60 min), P calcaratus (60 min) and D lablab (120 min) led to a lower apparent recovery of methionine (28·9–31·6%) and cystine (17·1–19·3%). Even with increased cooking times, the total essential amino acid levels in all three cooked seeds remained higher than that of the FAO/WHO requirement, except for methionine and cystine. Cooking (60 min) was found to be effective in reducing the tannin contents of P angularis, P calcaratus and D lablab seeds by 70·6, 64·6 and 74·6%, respectively. Upon cooking, phytate and trypsin inhibitory activity in different seeds were also reduced to different extents depending on the cooking times. ©1997 SCI

Effect of Various Processing Methods on Antinutrients andin VitroDigestibility of Protein and Starch of Two Chinese Indigenous Legume Seeds

The effect of various processing methods on antinutrients and in vitro protein and starch digestibility of Phaseolus angularis and Phaseolus calcaratus seeds was studied. The processes, which included soaking (12 and 18 h), cooking, autoclaving, and germination (24 and 48 h), significantly reduced (p < 0.05) the levels of antinutrients including phytates, tannins, trypsin inhibitors, and amylase inhibitors and significantly improved (p < 0.05) the digestibility of protein and starch as well. Since a significant negative correlation (ranging from −0.80 to −1.00) was found between these antinutrients and the digestibility of both protein and starch, the reduction in the levels of these antinutrients might partly account for the improved digestibility. Cooking as well as autoclaving brought about a more significant (p < 0.05) improvement in the digestibility of both protein and starch as compared with soaking and germination. In this study, all processing methods were more effective in improving the starch d...