Solubilization of California Small White Bean (Phaseolus vulgaris L.) Proteins

California Small White beans contained 25.90% crude protein on dry weight basis. Albumins accounted for 11.30% of the total crude proteins. Alkali (1N NaOH) extractable proteins had an isoelectric pH of about 4.0. About 88% of the total crude proteins were recovered employing acid/alkali extraction. Polyacrylamide gel electrophoretic analyses indicated that the acid soluble proteins were comprised of at least five components whereas the alkali soluble proteins consisted of at least two components.     

Characterization of Two α-Amylase Inhibitors from Black Bean (Phaseolus vulgaris)

Two inhibitors of α-amylase, I-1 and I-2, were purified from the black bean (Phaseolus vulgaris). The rate of complexation with porcine pancreatic α-amylase was very slow. I-l required 12 hr and I-2 6 hr for maximum inhibition at 30°C. The stoichiometry of complexation of α-amylase with I-1 was 2:1 and 1:1 with I-2. Optimum pH for complexation with I-1 ranged from 4.5 to 5.0 and 5.0 to 5.5 for I-2 and both were most stable at pH 3.0 to 4.0. An increase in ionic strength of the preincubation buffer from 0.106 to 0.906 enhanced the rate of inhibition 3 fold for both inhibitors. Maltose, a competitive inhibitor of α-amylase, added to the preincubation solution prevented complex formation for both inhibitors; however, it did not reverse the inhibition of the preformed complex. The dissociation constant for I-1 was 2.2 × 10^?9M and 3.8 × 10^?9M for I-2 at 30°C and pH 6.9. Both inhibitors functioned via a noncompetitive mechanism. I-2 was also stable at pH 2.0. I-2 was more stable to proteolytic digestion by trypsin than I-1 and was also stable to pepsin digestion.     

Solubilization and Electrophoretic Characterization of the Great Northern Bean (Phaseolus vulgaris L.) Proteins

Protein content of dry beans (Phaseiolus vulguris L.) cultivar Great Northern, was 26.10% (dry weight basis). The isoelectirc pH of the NaCl extractable proteins was about 4.4. Several salts, NaOH, and HCl were employed to solubilize the Great Northern bean proteins. Amongst all the protein solubilizing agents, Na₂CO₃, K₂SO₄, sodium dodecyl sulfate (SDS), and NaOH at respective concentrations of 0.5, 5, 5% (all w/v), and 0.02N were found to be better protein solubilizers than the rest; solubilizing 93.6g of Lowry protein per 100g of Kjeldahl protein. Albumins and globulins accounted for 21.18 and 73.40% respectively, of the total bean proteins. Protein content of albumins, globulins, protein concentrates, and protein isolates was 81.68, 92.26, 85.44, and 92.43% (dry weight basis) respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the bean flour, albumins, globulins, protein concentrates, and protein isolates revealed the presence of 22, 14, 10, 14, and 11 subunits, respectively. The bean flour, albumin's, globulins, protein concentrates and protein isolates were characterized by the predominance of subunits with apparent molecular weights of 294,000, 266,000, 123,000, 146,000, and 135,000 daltons, respectively. Isoelectric focusing of the bean flour, albumins, globulins, protein concentrates, and protein isolates indicated 15, 13, 15, 16, and 11 subunits, respectively. Molecular sieve chromatography of the bean flour proteins, albumins, and globulins followed by SDS-PAGE was also employed to study the complexities of these proteins.     

Thermal Effects on in vitro Protein Quality of Red Kidney Bean (Phaseolus vulgaris L.)

Significant thermal effects on in vitro protein quality of red kidney beans were observed. Beans autoclaved at 121°for 10 and 20 min, and common home-cooked beans had improved protein quality. Uncooked beans, and those autoclaved at 128°for 20 min and at 121°for 90 min had reduced protein quality compared to canned beans and those autoclaved at 110°for 20 min and at 121°for 40 and 60 min. Amino acid scores, essential amino acid index and available lysine (%), corrected for in vitro protein digestibility gave comparable results in evaluation of protein quality. Specific lysine, methionine, cysteine and other amino acid ratios overestimated protein quality.     

Sensory and Instrumental Texture of Snap Bean (Phaseolus vulgaris L.)

A recent study aimed to establish the correlation between instrumental (using Stable Micro System Texture Analyzer) and sensory texture analyses assays in snap bean pods (Phaseolus vulgaris L.). The rupture force correlated significantly and negatively with the sensory traits: parchment layer free, crispness, and stringlessness. Firmness measurements of the raw pods by the texture analyzer indirectly gave enough information to use it as a tool for sensory texture analyses of the processed beans. This could allow breeders to evaluate textural quality of cooked pods in the early stages of the breeding and selection program, thus saving time and costs in doing sensory texture analysis.     

3种保鲜剂对贵阳青棒豆贮藏品质的影响

以贵阳青棒豆为试材,研究3种保鲜剂对其贮藏品质的影响。结果表明:除二氧化氯缓释保鲜剂浓度过高加快腐烂外,涂膜处理和大蒜精油缓释保鲜剂均能显著抑制贵阳青棒豆腐烂率的增加;3种保鲜剂处理均能显著抑制失重率增加,贮藏5d时3种保鲜剂对贵阳青棒豆的呼吸速率影响不显著,贮藏10、15d时3种保鲜剂处理均促进呼吸速率;3种保鲜剂处理均显著抑制纤维素的增加,维持豆荚的L*和a*;天然固体保鲜剂有效抑制可溶性固形物含量(total soluble solid,TSS)、抗坏血酸的增加。其中,天然固体保鲜剂对贵阳青棒豆具有较好的保鲜效果。     

Gamma-Irradiated Dry Bean (Phaseolus vulgaris) Starch: Physicochemical Properties

Great Northern bean starch, irradiated at doses of 2.5–20 kGy, had increased free and total acidity, concomitant with a pH decrease from 6.9 to 3.9 and a rapid increase of reducing value. The swelling power of the bean starch decreased with irradiation dose. A rapid increase of water and 80% ethanol solubility at 25°C was observed at doses ≥10 kGy. No differences were detected on damaged starch or changes in X-ray diffraction pattern. ESR spectra of the irradiated bean starch after 9 and 11 mo storage (?40°C) showed the presence of long life radicals, which could be stabilized after adding water.     

Fermentation of the Great Northern Bean (Phaseolus vulgaris L.) and Rice Blends

Black gram (Phaseolus mungo) cotyledons could be substituted by the Great Northern bean (Phaseolus vulgaris L.) whole seeds in preparation of idli. The products prepared from conventional blend (black gram:rice :: 1:1 w/w) and the Great Northern bean-rice blend (1:2 w/w) were comparable. The latter had somewhat different flavor and a sticky top surface. Physicochemical changes in the Great Northern bean-rice blends (1:l and 1:2 w/w) paralleled each other while those in the fermentation of the beans alone differed from both the blends. No significant hydrolysis was observed in the major proteins in all the batters studied in 45 hr fermentation. Scanning electron microscopic observations indicated that starch granules were resistant to both, the fermentation and steaming.     

Functional Properties of the Great Northern Bean (Phaseolus vulgaris L.) Proteins: Emulsion, Foaming, Viscosity, and Gelation Properties

Functional properties of the Great Northern bean (Phaseolus vulgaris L.) flour, albumins, globulins, protein concentrates, and protein isolates were investigated. Protein concentrates had the highest water and oil absorption capacity (5.93 and 4.12 g/g, respectively) among all the samples studied. Protein concentrates registered the highest emulsion capacity (72.6g oil emulsified/g) while albumins had the highest emulsion stability (less than 5 ml separation of phase in 780 hr at room temperature of 21°C). Foaming ability of the Great Northern bean proteins was fair. Foamability of the proteins was concentration dependent.     

Physico-chemical and Functional Properties of Common Bean (Phaseolus vulgaris) Starches

Starch was isolated by a simple procedure from two varieties of Phaseolus vulgaris with outstanding agronomic performance. These varieties were negro queretaro and bayocel which have black and light brown colored seeds, respectively. The starch yields were 31.5% for negro qro. and 28.5% for bayocel. Commercial maize starch was used as reference. The granule size followed the order: negro qro. > bayocel > maize. Compared to maize starch, the legume starches had at least a similar water absorption capacity, formed a stable gel at lower concentrations and showed a Hunter total color closer to the employed white standard. The swelling and solubility were both temperature and pH dependent. Effects of pH on the pasting properties were also examined with the Brabender Viscograph. The viscosity of legume starches was increased after holding the paste at 90°C for 15 min. The retrogradation tendency of maize starch was much higher than that of legume samples. The physico-chemical and functional properties of common bean starches might suit some food industrial applications.     

Functional Properties of the Great Northern Bean (Phaseolus vulgaris L.) Proteins: Sorption, Buffer, Ultraviolet, Dielectric, and Adhesive Properties

Several functional properties of the Great Northern bean (Phuseolus vulguris L.) proteins were investigated. Sorption isotherms of the bean flour, albumins, globulins, protein concentrates, and protein isolates had similar patterns at corresponding temperatures. The bean flour registered higher equilibrium moisture content than albumins, globulins, protein concentrates, and protein isolates at corresponding temperature and equilibrium relative humidity. Buffer capacity of the bean proteins in the pH range 4–8 was modest. Modification (succinylation and oxidation) improved oil absorption capacity of the bean proteins. Water absorption capacity of the bean flour and protein isolates increased on modification. Modification of the bean proteins decreased the yellowness and increased the redness. About 1–2 KV/mm thickness potential difference was necessary for the passage of electrical current through these proteins. Globulins registered the highest stickiness (92N) among the samples investigated.     

Influence of Soaking and Cooking upon the Softening and Eating Quality of Black Beans (Phaseolus vulgaris)

Soaking and cooking treatments: were evaluated to establish the relationship of various regimes to the development of cooked bean texture and flavor of black beans (Phaseolus vulgaris L.). A salt combination soaking solution was most effective in promoting bean softening during cooking, compared to no soaking or a distilled water soak. A high correlation was observed between objective and sensory texture scores. An Instron puncture force of.150g (0.14 cm probe, 5 cm/min) accurately defined the “eating-soft” limit of texture acceptability.     

Evaluation of Canning Quality Traits in Black Beans (Phaseolus vulgaris L.) by Visible/Near-Infrared Spectroscopy

Black bean (Phaseolus vulgaris L.) processing presents unique challenges because of discoloration, breakage, development of undesirable textures, and off-flavors during canning and storage. These quality issues strongly affect processing standards and consumer acceptance for beans. In this research, visible and near-infrared (Vis/NIR) reflectance data for the spectral region of 400–2,500 nm were acquired from intact dry beans for predicting five canning quality traits, i.e., hydration coefficient (HC), visual appearance (APP) and color (COL), washed drained coefficient (WDC), and texture (TXT), using partial least squares regression (PLSR). A total of 471 bean samples harvested and canned in 2010, 2011, and 2012 were used for analysis. PLSR models based on the Vis/NIR data showed low predictive performance, as measured by correlation coefficient for prediction (R _pred) for APP (R _pred?=?0.275–0.566) and TXT (R _pred?=?0.270–0.681), but better results for predicting HC (R _pred?=?0.517–0.810), WDC (R _pred?=?0.420–0.796), and COL (R _pred?<?0.533–0.758). In comparison, color measurements from a colorimeter on drained canned beans showed consistently good predictions for COL (R _pred?=?0.796–0.907). In spite of the low or relatively poor agreement among the sensory panelists as determined by multirater Kappa analysis (K _free of 0.20 for APP and 0.18 for COL), a linear discriminant model using the Vis/NIR data was able to classify the canned bean samples into two sensory quality categories of “acceptable” and “unacceptable”, based on panelists’ ratings for APP and COL traits of canning beans, with classification accuracies of 72.6 % or higher. While Vis/NIR technique has the potential for assessing bean canning quality from intact dry beans, improvements in sensing and instrumentation are needed in order to meet the application requirements.     

Isolation, Partial Characterization and Modification of the Great Northern Bean (Phaseolus vulgaris L.) Starch

The yield of the Great Northern bean starch was 18.23% (bean flour basis). The starch granule size ranged from 12 × 12 μm to 58 × 40 μm (length × width). The shape of starch granules was round to oval to elliptical, and in some cases, concave as well. Lamellae were present on all the starch granules observed. Amylose content of the starch was 10.2% (starch basis). Hog pancreatic α-amylase hydrolyzed more starch than did malt α-amylase under similar conditions. The Great Northern bean starch had good water and oil absorption capacities at room temperature (21°C). The bean starch formed a stable gel at concentrations of 7% and above (w/v). The viscoamylographic studies of the isolated starch indicated the restricted-swelling character of the bean starch.     

Isolation and Partial Characterization of an Arabinogalactan from the Great Northern Bean (Phaseolus vulgaris L.)

A trichloroacetic acid-soluble polysaccharide of the Great Northern bean (Phaseolus vulgaris L.) was isolated. Arabinose and galactose were the major constituents of this polysaccharide (92.5% of the total mass). The arabinose to galactose ratio was 2.0:1.7. Viscosity of the aqueous polysaccharide dispersion was concentration, temperature, and pH dependent. Highest viscosity for a 0.5% (w/v) aqueous dispersion was observed at a pH of about 6.0.     

Gamma-Irradiation Affects Some Physical Properties of Dry Bean (Phaseolus vulgaris) Starch

Gamma-irradiated great northern (GN) bean starch (2.5–20 kGy) showed apparent increased susceptibility to central fissures. Bean damage during scanning electron microscopy was observed using ≥400OX magnification on GN bean starch samples. Approximate molecular weights estimated by gel filtration chromatography Sepharose Cl-2B of control GN bean starch were: amylopectin >2×10⁶ and amylose 2×10⁵. Amylose-like fraction of irradiated bean starch (20 kGy) revealed two peaks ～6.9×10⁴ and 1.5×10⁵ daltons. Differential scanning calorimetry showed an increase in gelatinization enthalpy and a small increase in gelatinization peak temperature at 20 kGy suggesting a reorganization of the crystalline and amorphous phases of the starch granule.     

Bean (Phaseolus vulgaris L.) polysaccharides modulate gene expression in human colon cancer cells (HT-29)

Colorectal cancer is one of the most commonly diagnosed cancers in the United States and the third cause of cancer mortality in México. We present the results of molecular changes involved in p53 pathway in HT-29 cells evaluated by PCR array after 24 h exposure to in vitro fermented bean (cv. Bayo Madero) polysaccharide extract with human gut flora (FE-hgf). Significant differences were detected in 72 of 84 human p53-mediated signal transduction response genes involved in apoptosis, cell cycle and cell proliferation showed significant expression changes. Apoptosis genes, SIAH1, PRKCA and negative regulation of the cell cycle gene MSH2 were the highest up-regulated genes (30.5-, 18.4- and 9.8-fold, respectively), whereas cell cycle genes CHEK1 and GADD45A were markedly down regulated (21.4- and 9.1-fold, respectively). We demonstrate that common beans and or/it´s polysaccharides modulate gene expression profiles in HT-29 cells, providing insight about the mechanism underlying its overall chemoprotective function against colon carcinogenesis.     

Effect of Processing on Anti-nutritional Factors of Red Kidney Bean (Phaseolus vulgaris) Grains

The effect of different processing methods (soaking in water or solutions of sodium bicarbonate, citric acid, soaking plus cooking, and germination) on anti-nutritional factors (phytic acid, total polyphenols, tannins, and hydrocyanic acid) of red kidney bean was studied. The anti-nutritional factors were reduced significantly (P < 0.001) with processing techniques. Cyanide contents were most effectively (25%) reduced by cooking after soaking in sodium bicarbonate solution, followed by germination. The most drastic effect was noted on tannin contents. Cooking after soaking in either citric acid or sodium bicarbonate solutions almost eliminated it. However, simple soaking in water did not result in any reduction in tannin contents. Reduction in total polyphenols was 78.7% with cooking after soaking in sodium bicarbonate solution. Phytic acid contents were reduced only with germination treatment (42.6%), while the other treatments did not bring about any large reduction.