Denaturation by heat,sodium dodecyl sulphate and dithiothreitol of globulins and phaseolin from dry bean (Phaseolus vulgaris L.)

The electrophoretic pattern of the untreated common bean globulin cv. Flor de Mayo had 7 protein fractions ranging from 620 to 120 kilodaltons (kd). The last molecular weight corresponds to the monomeric form. One of the objectives of the present work was to establish a comparison among denaturation by heat, sodium dodecyl sulphate (SDS) and dithiothreitol (DTT). At pH 6.0, two bands were resistant to heat treatment, after SDS treatment of the untreated globulin several bands disappeared and two new bands with 26 and 15 kd appeared. DTT did not change the electrophoretic pattern, due to the small quantity of free SH groups in the globulin. At pH 6.0, phaseolin is partly resistant to heat denaturation due to aggregation in an acidic environment. Isoelectrofocusing (IEF) and SDS polyacrylamide gel electrophoresis (SDS-PAGE) separated phaseolin into 10 protein fractions. The hypothesis is that phaseolin or globulin aggregation is due to the charge difference of fractions.     

Phytic acid in stored common bean seeds (Phaseolus vulgaris L.)

Four varieties of common bean seeds stored at 4°C, 80% relative humidity, for one to eight years showed no differences in proximal chemical composition, Seeds 5–6 years old absorbed more water than 1 to 4 year-old seeds. The cooking time required for five year-old seeds was 6 hours, while the fresh seeds needed 3/4-to-one hour cooking time. The most remarkable difference was in phytic acid content, which decreased 94% to 98% during long storage.     

Unavailable carbohydrates in common bean cotyledon (Phaseolus vulgaris L.) Canario group

Unavailable carbohydrates in cotyledon flour were quantified from four varieties of common bean (Phaseolus vulgaris L) belonging to the Canario group. The pectin content, as percentage of anhydrogalacturonic acid, ranged between 1.57% and 2.3%. Percentages of hemicellulose A and B were similar, with average values of 2.81% and 2.61%, respectively. The polysaccharide extracted with 10% trichloroacetic acid was determined; its yield was 3.17%. This value dropped to 2.35% when the cotyledon flour was previously hydrolyzed with polygalacturonase. The average value of cellulose was 1.36%.     

Characterization of Phaseolus vulgaris L. Landraces Cultivated in Central Italy

Eight Phaseolus vulgaris L. landraces cultivated on farm in marginal areas of Central Italy (Lazio region) were investigated in order to evaluate chemical composition of storage proteins and secondary metabolites fractions. The total protein content showed some differences among landraces; the maximum value was next to 30 g for 100 g of dry weight. The seed storage proteins were screened by polyacrylamide gel electrophoresis (SDS/PAGE): seven landraces exhibited phaseolin patterns type S, one landrace showed a phaseolin pattern type T. A morphological analysis of cotyledon parenchyma performed by scanning electron microscopy (SEM) revealed differences in size of starch granules. Moreover the polyphenolic composition was investigated using HPLC-APCI; from the methanol extracts a flavonoid, kaempferol, and a coumarin, 5,7-dimethoxycoumarin, were identified. To our knowledge, this is the first time that 5,7-dimethoxycoumarin has been reported in P. vulgaris seeds.     

The degradation of lectins,phaseolin and trypsin inhibitors during germination of white kidney beans,Phaseolus vulgaris L.

White kidney beans (Phaseolus vulgaris), cv Processor, contain a relatively high content of phaseolin (storage protein), lectins and a special group of glycoproteins as well as a considerable amount of protein-type trypsin inhibitors. Protein digestion of raw Processor beans in monogastrics, for example pigs, is disturbed by poorly digested, phaseolin lectins, which can bind to carbohydrates in brush border membranes of the small intestinal epithelium, and trypsin inhibitors. The effect of the germination of white kidney beans on lectins, phaseolin and trypsin inhibitors was studied in order to achieve a degradation of lectins, phaseolin and trypsin inhibitors and an increase ofin vitro enzymatic hydrolysis of the protein of bean flour. Therefore, whole bean extracts were examined throughout a germination period of up to seven days for their lectin and phaseolin pattern, lectin content, binding capacities of functional lectins towards brush border membranes and trypsin inhibitor content. In addition thein vitro enzymatic hydrolysis by pepsin and pancreatin of the protein from flours of (un)germinated white kidney beans was studied. SDS-PAGE demonstrated a degradation of E-lectins and a disappearance of L-lectins and phaseolin during germination. Results indicated a decrease of the lectin content by 85%, a loss of binding capacities of functional lectins towards brush border membranes by 91%, and a decrease of trypsin inhibitors by 76%, in bean flour after germination for seven days. A maximum inin vitro enzymatic hydrolysis of protein from bean flour was already established after germination for half a day.     

Biochemical Composition and Indigestible Oligosaccharides in Phaseolus vulgaris L. Seeds

Common beans have a high nutritional value, but contain galactooligosaccharides (GO), which cause flatulence and intestinal discomfort in humans. The biochemical composition of ten bean cultivars was determined to select those of high protein and low GO contents. The cultivars varied in carbohydrate (47.02–60.17%), GO (3.12 – 5.71%), protein (22.17–33.50%), lipid (1.13–1.81%), moisture (11.42–12.93%) and ash contents (4.08–5.61%). ‘Mexico 222’ presented the highest α-galactosidase activity. Protein and GO contents were positively correlated. ‘Perry Marrow’ combined high protein and low GO concentrations, indicating it can be used in improvement programs aiming at high-quality cultivars for human consumption.     

菜豆中总黄酮提取工艺及含量测定

目的测定菜豆豆荚总黄酮含量,优化菜豆中黄酮提取工艺。方法以芦丁为对照品通过紫外分光光度法测定总黄酮含量,将回流法、超声法、煎煮法提取黄酮类化合物的提取效率进行对比,采用正交法优化了超声提取工艺。用最佳提取工艺验证实验结果。结果提取次数对黄酮提取率影响显著．超声时间和乙醇浓度对提取率影响不显著。结论最佳提取工艺为85％乙醇、超声60min、提取3次,菜豆中总黄酮含量为158．86mg／100g。     

Variability of Nutritional and Cooking Quality in Bean (Phaseolus vulgaris L) as a Function of Genotype

Screening of natural biodiversity for the better quality traits are of prime importance for quality breeding programs. The objective of this investigation was to select candidate accession of bean having high concentrations of protein as well as macro and micro minerals with good cooking quality for use as parents in breeding programme for these compounds. Thirty-five accessions of bean (Phaseolus vulgaris L) were field grown and their seeds were analyzed for their cooking quality and nutritional composition. Wide variations were observed in most of the measurements e.g. protein (18.7–26.2%), iron (79.4–137.6 ppm) and hardness after cooking (4.65–9.88 Kg) suggesting that there are considerable levels of genetic diversity. Across all accessions the concentration of potassium was negatively correlated with protein (r = −0.43, P < 0.05). Concentrations of protein was significantly greater in accessions VIII, XIII and XIX compared to other accessions analyzed. Iron concentrations were greatest (137 ppm) in XIX and lowest (79 ppm) in XXVII. Lines with less cooking time were line III, X, XXVI, XXX and XXXI. Bean line XIX contains high protein (24.9%) with high zinc (33.3 ppm) and highest iron (137.6 ppm), but it has high hardness after cooking (7.32 kg). Four clusters were computed by cluster analysis that explained quite a good variation in the traits. The great variability for these attributes suggests that these selected accessions may be useful as parents in hybridization programs to produce bean with value-added traits. This information was also potentially useful for pulse breeders working on the development of new varieties.     

Partial chemical composition,free soluble sugars and unavailable carbohydrates in the embryonic axis and seed coat ofPhaseolus vulgaris L. (Canario group)

Four varieties of common bean were examined, but there were no significant differences among them. Crude protein content (46.7% and 49.0%) was the main constituent in embryonic axes. The average values of ash, crude fiber and ether extract were 4.2%, 3.7% and 3.0% respectively. Starch was approximately three times more abundant (7.5%) than cellulose (2.7%). Hemicellulose B values were lower (5.5%) than hemicellulose A (9.2%). The mean value of the pectic substances in embryonic axes was 12.3%. The free ethanol-soluble sugars ranged from 2.9% to 4.9%. Verbascose, stachyose, raffinose, sucrose, and galactose were identified and quantified in embryonic axes. Seed coat flour contained cellulose (30.6%), ether extract (0.4%), ash (2.8%), and protein (5.4%). Free ribose, mannose, arabinose, and galactose were present in seed coats in amounts ranging from 0.009% to 0.031%.     

Use of plant extracts in the control of common bean anthracnose

Three hundred (300) methanol extracts of barks, leaves, flowers and stems of 200 plant species from Alto Rio Grande and Vale do São Francisco regions, State of Minas Gerais, Brazil, were prepared and submitted to an in vitro growth test with the fungus Colletotrichum lindemuthianum, causal agent of anthracnose in common bean. Extracts from 13 plant species (Astronium fraxinifolium, Inga marginata, Malva sylvestris, Matayba elaeagnoides, Miconia argyrophylla, Myrcia fallax, Ocimum gratissimum, Origanum vulgare, Rollinia emarginata, Siparuna arianeae, Styrax pohlii, Tabebuia serratifolia and Trichilia pallida) presented antifungal activity and were used in other in vitro assays. Extracts from M. argyrophylla, M. fallax, O. vulgare, S. arianeae and S. pohlii were the most promising for the inhibition of the mycelial growth while the extracts of M. argyrophylla, M. elaeagnoides and O. gratissimum presented the best results for the inhibition of conidial germination. Under greenhouse conditions, the extracts of M. argyrophylla and O. vulgare caused the greatest reductions (41.82% and 37.65%, respectively) in disease severity when a local effect assay was carried out. In the systemic effect assay, also in a greenhouse, the most promising extracts were those from I. marginata, M. argyrophylla, M. fallax, M. sylvestris, O. gratissimum, O. vulgare and S. arianeae, which reduced the severity of the anthracnose to values below 35% of the observed for the control. Therefore, future studies with these plant species should be carried out to develop new products to control the common bean anthracnose.     

Intestinal absorption of D-galactose in the presence of extracts fromPhaseolus vulgaris hulls

The relatively low nutritional value of protein from legume seeds has been attributed to the occurrence of some antinutritional factors and the poor content in sulphur aminoacids, which leads to undesirable physiological and biochemical alterations. However, the intimate nature of these processes remains unclear. In order to evaluate the influence of naturally occurring substances of legume constituents on nutrient utilization, the intestinal absorption of D-galactose in the presence of aqueous or alcoholic extracts, obtained fromPhaseolus vulgaris hulls, has been measured by use of thein vivo successive absorption technique.Aqueous extracts inhibited significantly (p<0.01) the uptake of D-galactose at different times of exposure, while no changes in sugar transport were observed with the alcoholic solutions. Polyamide treatment (a polyphenolic complexing agent) of the aqueous extracts decreased its ability to inhibit sugar uptake. Kinetic studies showed that the aqueous fractions modifyV _max values for D-galactose absorption and alsoK _T data. This inhibition appeared to be reversible after short periods of exposure, affecting mainly the active component of transport. Therefore, it can be suggested that some substances, contained in aqueous extracts ofPhaseolus vulgaris reduce sugar absorption. Furthermore, our studies seem to indicate that polyphenols are, at least partly, involved in this phenomenon.     

Effects of various water or hydrothermal treatments on certain antinutritional compounds in the seeds of the tribal pulse,Dolichos lablab var.vulgaris L.

Effects of soaking, cooking and autoclaving on changes in polyphenols, phytohaemagglutinating activity, phytic acid, hydrogen cyanide (HCN), oligosaccharides and in vitro protein digestibility were investigated in seeds ofDolichos lablab var.vulgaris. Both distilled water and NaHCO₃ solution soaking and autoclaving significantly reduced the contents of total free phenolics (85–88%) compared to raw seeds. Autoclaving (45 min) reduced the content of tannins by upto 72%. Soaking seemed to have limited effect in eliminating phytohaemagglutinating activity, whereas autoclaving (45 min) seemed to eliminate the haemagglutinating activity completely. The reduction in content of phytic acid was found to be some what greater in distilled water soaking (28%) compared to NaHCO₃ solution soaking (22%). Only a limited loss in content of phytic acid was observed under cooking as well as autoclaving. Loss of HCN was greater under autoclaving (87%) compared to the other processes studied. Of the three sugars analysed, soaking reduced the level of verbascose more than that of stachyose and raffinose. Autoclaving reduced the content of oligosaccharides more efficiently (67–86%) than ordinary cooking (53–76%). Autoclaving improved the in vitro protein digestibility (IVPD) significantly (13%). Of all the different water and hydrothermal treatments studied autoclaving seemed to be the most efficient method in improving IVPD and eliminating the antinutrients investigated except phytic acid.     

Studies on green beans (Phaseolus vulgaris L.)

The phytoalexins produced after the inoculation of green bean pods (Phaseolus vulgaris L.) with the spore suspension of three fungi viz.Fusarium solani, Penicillium patulum andPhytophthora megasperma were studied. Five phytoalexins were isolated and identified as phaseollin, coumestrol, kievitone, phaseollidin and 6--hydroxyphaseollin. Their identity was proved according to m.p., TLC, UV and MS by comparison with authentics. Moreover, the preliminary screening of their antifungal activity was carried out.     

Effect of imazamox plus bentazon on dry bean (Phaseolus vulgaris L.)

Imazamox plus bentazon has the potential to provide broad spectrum weed control in dry bean (Phaseolus vulgaris L.). Field trials were conducted in Ontario over a two year period (2003 and 2006) to evaluate the effect of imazamox plus bentazon applied post-emergence at 25 + 600 and 50 + 1200 g ai ha⁻¹ on black, brown, cranberry, kidney, otebo, pinto, white and yellow eye beans. Treatments included a non-treated check. All treatments were maintained weed free during the growing season. The eight market classes responded similarly to imazamox plus bentazon. Imazamox plus bentazon applied post-emergence caused less than 4% visible injury at 7, 14 and 28 days after treatment. Imazamox plus bentazon applied post-emergence did not have any effect on plant height, shoot dry weight, seed moisture content and yield of dry bean. Based on these results, imazamox plus bentazon at the proposed maximum use dose can be safely used for weed management in black, brown, cranberry, kidney, otebo, pinto, white and yellow eye bean production in Ontario. Additional research is needed to determine if cultivars within a market class of dry bean differ in their response to imazamox plus bentazon.     

Antiradical Capacity and Induction of Apoptosis on HeLa Cells by a <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> Extract

Jamapa bean is a black Phaseolus vulgaris variety rich in condensed tannins, anthocyanins and flavonols with interesting biological activities. The objective of this work was to evaluate the antiradical capacity (ARC) of a Jamapa bean methanolic extract (BME) and some of the proanthocyanidin-rich fractions derived from it, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The effect of the BME on some proteins involved in apoptosis on HeLa cells was also evaluated. A strong correlation between proanthocyanidin concentration in BME and antiradical capacity was found, suggesting that these compounds contribute significantly to antiradical activity. BME was a better radical scavenger than butylated hydroxytoluene (45.6 and 33.9% ARC at 400 μM, respectively). Two proanthocyanidin-rich fractions obtained after a preliminary separation of the BME using Toyopearl (TP4 and TP6) exhibited a higher antiradical activity than the parent extract. The treatment of HeLa cells with 35 μg BME/ml/24 h increased the expression of Bax and Caspase-3, pro-apoptotic proteins (6.13 and 1.2 times for Caspase-3 and Bax, respectively). The mechanism of action of some proteins involved in apoptosis was also evaluated, and the results suggest that black Jamapa bean could be an important source of polyphenolic compounds with potential biological use as antioxidant and anticancer agents.     

Genetic analysis for resistance to bean fly (Ophiomyia phaseoli) and seed yield among common bean genotypes in a semi-arid environment

Bean fly (Ophiomyia spp.) is a major field pest limiting common bean production in eastern Africa. The genetic enhancement of beans for resistance to insect pests is essential for minimizing yield losses arising from crop damage. The objectives of this study were to (1) assess combining ability for bean fly resistance and seed yield accumulation in common bean and (2) estimate genetic parameters associated with resistance for formulating further breeding strategy. Four parents with known reaction to bean fly were crossed with four locally adapted genotypes in an 8 × 8 half diallel mating design. Parents and F₂ progenies were grown in an alpha-lattice design replicated twice in an open-field and subjected to natural populations of bean fly for two cropping seasons under semi-arid conditions. Similarly, two resistant and two susceptible parents were selected and crossed to produce populations for generation means and variances components analysis. Results revealed that both general combining ability (GCA) and specific combining ability (SCA) mean squares were significant (p ≤ 0.05) for all four traits studied except SCA for stem damage during one cropping season. Among the parents, GBK 047858 was the best general combiner for all the traits studied across seasons except for stem damage during long rains (LR) 2009. Besides, genotypes GBK 047821 and Kat × 69 (a locally adapted variety) were generally good general combiners for resistance traits as well as seed yield. General predictability ratio (GPR) values ranging from 0.63 to 0.90 were obtained for plant mortality, stem damage, pupae in stem and seed yield across cropping seasons. These results established the predominance of additive gene effects (fixable variation) over the non-additive effects in controlling the traits. Low to moderate narrow sense heritability values ranging from 0.22 to 0.45 were obtained for pupae in stem. Such heritability estimates indicate that although additive gene components were critical in the inheritance of resistance for the trait, non-additive gene action were also important in addition to the environmental effects.     

菜豆高产栽培技术研究

从选种的注意事项等方面介绍了莱豆的品种选择,分析了菜豆的外部形态、生物学特性及对环境的要求等特征特性,同时阐述了莱豆的栽培季节及栽培管理方法,并论述了莱豆的常见病虫害及其防治方法。     

Comparison of procedures to determine protein content of developing bean seeds (Phaseolus vulgaris)

Micro-Kjeldahl, Lowry and Bradford procedures were compared for determining the protein content ofPhaseolus vulgaris seeds during their development. Micro-Kjeldahl and biuret techniques were also compared with mature seeds of a normal and a genetically-improved bean cultivar. The protein contents of casein and soy protein isolate were as well estimated by these four methods. For many samples of both bean and food protein products large disagreements were found between micro-Kjeldahl and the other three procedures.     

Methionine-containing proteins in twoPhaseolus vulgaris cultivars with different methionine bioavailabilities

The full utilization of legumes as human food is limited by a deficiency of sulfur amino acids, low protein digestibility, low methionine bioavailability and the presence of anti-nutritional factors. A new cultivar ofPhaseolus vulgaris (Carioca 80) has 56.8% available methionine, compared with 29.3% availability in the parent cultivar Carioca. The total methionine content, denaturing gel electrophoretic patterns of methionine-containing proteins, and the percentage of phaseolins (the major storage proteins in Phaseolus) relative to the total protein are similar in the two cultivars. Although the digestibility of the two cultivars is similar, the increased biological value of Carioca 80 may indicate that there are differences in overall bean composition that affect protein hydrolysis and utilization. We suggest the tentative explanation that this is due to differences in the distribution of methionine in the methionine-containing proteins of the two cultivars.     

Evaluation of common bean lines for their reaction to tomato yellow leaf curl virus-Ir2

Tomato yellow leaf curl virus (TYLCV) can cause an economically relevant disease in the major tomato growing regions, and no resistance has been identified in commercial and wild tomato cultivars in Iran. In the present study, 34 common bean lines were screened for their reaction to TYLCV-Ir2 under greenhouse conditions. The experiment was conducted in a randomized complete block design with three replications. Bean plants were inoculated at the first trifoliate stage with viruliferous whiteflies (Bemisia tabaci biotype B) and were then sprayed with an insecticide and maintained in whitefly-proof greenhouse. The inoculated plants were monitored for the development of symptoms and the presence of viral DNA by polymerase chain reaction (PCR) four weeks after inoculation. Results revealed that out of the 34 lines, five were resistant. These lines exhibited either no symptoms or very mild symptoms and no viral DNA was detected in them by PCR. Two lines, which showed no typical disease symptoms but contained viral DNA, were identified as tolerant to TYLCV-Ir2. The vector feeding preference for common bean lines was assessed. Results indicated a significant difference in adult whitefly numbers among bean lines but there was no relationship between the number of whiteflies and disease symptom severity. The resistance to TYLCY-Ir2 expressed in common bean lines may be useful as source of resistance for the development of resistant commercial common bean cultivars.