Protein isolates rich in methionine from the edible dry bean (Phaseolus vulgaris L.)

Several extraction and fractionation schemes were investigated for their ability to fractionate edible dry bean seed proteins into classes of variable methionine content. Isoelectric precipitation or dialysis from a protein solution of low ionic strength resulted in protein isolates having methionine content equal to or lower than the average seed methionine. A protein isolate rich in methionine was obtained by the adjustment of a high ionic strength protein solution at pH 4.1. This methodology excluded the major storage seed proteins, which are known for their low methionine content.     

Microwave-assisted extraction of phenolics from bean (Phaseolus vulgaris L.)

Phenolic phytochemicals are associated with many health benefits, and it would be useful to develop improved methods for their extraction from bean. In this work, we showed that microwave-assisted extraction was an effective method. Eight bean types important in the Northarvest region of North America, which includes North Dakota and Minnesota, were chosen for this study. Four temperatures (25, 50, 100 and 150 °C) and three solvents (water, 50% ethanol in water and 100% ethanol) were investigated. As expected, colored beans contained higher concentrations of extractable phenolics, and in most cases the concentration of phenolics was much higher in the hull (testa) than in the cotyledon. Extraction efficiency was superior at higher extraction temperatures. The most effective extraction was achieved at a temperature of 150 °C using 50% ethanol. Total phenolics contents determined by microwave-assisted extraction with water at 100 °C were two to three times those determined by conventional extraction with water at the same temperature.     

Proteins isolated from Ganxet common bean (Phaseolus vulgaris L.) landrace: techno-functional and antioxidant properties

Ganxet protein isolates (GPI) were assessed for antioxidant and functional properties including emulsifying and foaming capacity. The protein content and water activity (a_w) value of GPI were 91.08 ± 4.15% and 0.248 ± 0.008%, respectively. The oil- and water-holding capacities of GPI were calculated as 2.76 ± 0.33 and 1.25 ± 0.11 g g⁻¹ of GPI, respectively (P < 0.05). Foaming and emulsifying properties were found to be pH-dependent (P < 0.05). The highest foaming capacity values were observed at pH 8.0 and 10.0 and were calculated as 86.25 ± 5.30% and 78.75 ± 1.77%, respectively. In addition, the generated emulsions were found to be stable, especially at pH 8.0 and 10.0 with emulsion stability values of 94.1 ± 0.0 and 93.9 ± 0.1, respectively (P < 0.05). Results obtained in the current study demonstrate the potential applications of Ganxet-derived proteins as techno-functional ingredients for the development of novel foods.     

Protein profile and antioxidant capacity of processed seeds from two common bean (Phaseolus vulgaris L.) cultivars

Common bean (Phaseolus vulgaris L.) seeds are an economical protein source rich in bioactive compounds with antioxidant activity. In this work, we evaluated processed seeds from two common bean cultivars regarding protein profile and antioxidant capacity before and after enzymatic digestion in vitro. We provided protein maps by two-dimensional electrophoresis (2-DE) of seeds germinated during 36 h and 72 h. The principal component analysis (PCA) showed that protein abundance had more variation on germination times than the cultivar ones. Seeds germinated for 36 h showed greater antioxidant capacity compared to germination for 72 h and cooking, before and after enzymatic digestion. In protein isolates, cooking associated with digestion provided better antioxidant capacity. Germination time influences protein expression as well as the antioxidant capacity of common beans. Furthermore, in vitro digestion increases the antioxidant capacity of cooked bean protein isolates.     

响应曲面法研究贮前热处理对油豆角品质的影响

以油豆角为原料,采用响应面方法,研究贮前热空气处理温度和处理时间对油豆角冰温贮藏过程中品质的影响。通过中心优化组合设计得出最佳热处理参数为:热处理温度53℃,热处理时间19min。油豆角热处理后冰温贮藏优势明显,油豆角膜透性的增加趋势得以延缓,过氧化物酶活性得到抑制。     

The relationships between physicochemical properties and conformational features of succinylated and acetylated kidney bean (Phaseolus vulgaris L.) protein isolates

The effects of succinylation and acetylation on some physicochemical properties and conformational features of kidney bean protein isolate (KPI) were investigated. The extent of N-acylation progressively increased up to 93–94% with increasing anhydride-to-protein ratio (0–1.0 g g^?1), while the O-acylation occurred only after extensive blocks of ε-amino groups. Zeta potential and size exclusion chromatography analyses indicated that the acylation and the succinylation in particular led to decreases in isoelectric point and zeta potential at neutral pH, in an extent of acylation dependent manner, while the association/dissociation state of the vicilin was slightly affected by the acylation. The surface hydrophobicity was also remarkably affected by the acylation, but the influence varied with the type and extent of acylation. Differential scanning calorimetry (DSC), intrinsic fluorescence and near-UV and/or far-UV CD spectroscopic analyses showed significant changes in tertiary and/or secondary conformations of the proteins in KPI, with extent of acylation, especially extent of succinylation. These phenomena suggest close relationships between the physicochemical properties and tertiary and/or secondary conformational features of the proteins in acylated KPI samples. It is also suggested that the physicochemical and conformational properties of KPI could be modulated by selecting the type and level of the applied anhydrides.     

Dehulling and selected physical characteristics of Canadian dry bean (Phaseolus vulgaris L.) cultivars

The tangential abrasive dehulling device (TADD) was used to evaluate the dehulling properties of 13 dry bean cultivars from five market classes. Hull yield or percent kernel removed was cultivar dependent and increased linearly (r² ? 0.984) as dehulling time increased from 30 to 120 s. Hull yield was significantly different within cultivars of great northern and pink bean market classes and there were no significant (p < 0.05) differences within black and pinto bean cultivars. Bean cultivars differed significantly in dehulling parameters–rate coefficient (RC) and abrasive hardness index (AHI), although the differences were small. Cluster analysis, based on dehulling parameters, segregated the cultivars into three major groups; AC Black Violet, AC Black Diamond, CDC Jet, and subgroup AC Resolute and AC Agrinto (AHI, 12.7–14.9 s); Othello, AC Early Rose and AC Polaris and the subgroup CDC Minto and Winchester (AHI, 11.7–12.5 s); and AC Redbond and Viva (AHI < 11 s). Black beans were the hardest to dehull since the longest time (928 s) was required to completely remove the hulls by abrading on average, 50 g/100 g seed. Multiple regression analysis showed that dehulling parameters were not related to any seed characteristics, although seed length, width, thickness and weight were highly correlated (r² ? 0.786, p < 0.005).     

Physiological traits related to terminal drought resistance in common bean (Phaseolus vulgaris L.)

BACKGROUND: A major problem in common bean (Phaseolus vulgaris L.) agriculture is the low yield due to terminal drought. Because common beans are grown over a broad variety of environments, the study of drought‐resistant genotypes might be useful to identify distinctive or common mechanisms needed for survival and seed production under drought. RESULTS: In this study the relationship between terminal drought resistance and some physiological parameters was analysed using cultivars contrasting in their drought response from two different gene pools. Trials were performed in three environments. As expected, drought treatments induced a decrease in leaf relative humidity and an increase in leaf temperature; however, when these parameters were compared between susceptible and resistant cultivars under optimal irrigation and drought, no significant differences were detected. Similar results were obtained for chlorophyll content. In contrast, analysis of relative water content (RWC) and stomatal conductance values showed reproducible significant differences between susceptible and resistant cultivars grown under optimal irrigation and drought across the different environments. CONCLUSIONS: The data indicate that drought‐resistant cultivars maximise carbon uptake and limit water loss upon drought by increasing stomatal closure during the day and attaining a higher RWC during the night as compared with susceptible cultivars, suggesting a water balance fine control to achieve enough yield under drought. Copyright © 2012 Society of Chemical Industry     

Evaluation of blanching requirements of green French bean (Phaseolus vulgaris L.) pods on basis of thermal resistance of its peroxidase

Green pods of French beans CV, pant Anupam were blended with distilled water, filtered and extract pH was adjusted to 5.25, 5.65, 5.85, 6.25 or 6.65 using 20 % citric acid or 1 N NaOH. Thermal inactivation times (TIT) of peroxidase were determined by TIT tube method. The corrected F₁₀₀ [min] and z [°C] at the above five pH values were 1.77 and 15.8, 1.43 and 14.1, 0.95 and 11.0, 0.29 and 8.7, and 0.17 and 8.1, respectively. The corresponding energy of activation values were 157, 177, 218, 286 and 307 KJ mole^?1. The actual blanching times in boiling media calculated from the above data were 4.0, 3.5, 2.5, 1.0 and 0.5 min, respectively, showing that blanching requirements of French beans decreased with increase in the pH of the blanching media.     

Physicochemical properties of acetylated starches from some Indian kidney bean (Phaseolus vulgaris L.) cultivars

Starches separated from four kidney bean cultivars were modified by acetylation to reduce retrogradation and increase gel stability and compared with respective native starches (data of native starch reported by Wani et al., 2010 ). Acetylation was carried out by treating starches with 0.04 and 0.08 g of acetic anhydride per gram of starch dry weight basis (dwb) at 25 °C and pH between 8.0 and 8.5. The extent of acetylation increased proportionally with the concentration of acetic anhydride used. The pasting curves of 10.7% starch determined by Rapid Visco Analyzer at 160 rpm showed that acetylation decreased the setback viscosity values by 0.64–34.58% and pasting temperature by 4.4–9.2 °C when compared with the native starch. Differential scanning calorimetry observations also revealed significant (P ≤ 0.05) decrease in gelatinisation temperature of acetylated starches than the corresponding native starches. Hardness of starch gels varied between 14.3 and 44.0 g, which was significantly (P ≤ 0.05) lower than the corresponding native starch gels.     

Antioxidant Potential of Pea Beans (Phaseolus vulgaris L.)

ABSTRACT: Four bean varieties ( Phaseolus vulgaris L.) (white kidney, red pinto, Swedish brown, and black kidney) and their hull fractions were extracted with 80% acetone and evaluated for their phenolic contents and antiradical activities. Total phenolic content of bean hulls and whole seed extracts ranged from 6.7 to 270 and 4.9 to 93.6 mg/g extract as catechin equivalents, respectively. Trolox equivalent antioxidant capacity (TEAC) assay revealed that the antioxidant capacity of red, brown, and black whole seed extracts was in the same order of magnitude with little variation. TEAC values of red and brown whole seed extracts were superior to that of black whole seed extract. On the basis of the total phenolic content and TEAC values, it can be deduced that colored beans possess superior antioxidative activity compared with white beans. The hydrogen peroxide scavenging capacity of different bean extracts ranged from 58% to 67% at 50 ppm and 65% to 76% at 100 ppm. The corresponding superoxide radical scavenging capacity was 24% to 29% at 50 ppm and 53% to 60% at 100 ppm. The 2,2–diphenyl-1–picrylhydrazyl (DPPH) radical scavenging capacity of black bean whole seed extracts was 22% at 50 ppm, whereas the other extracts showed 100% scavenging of this radical at both 50 and 100 ppm levels. The hydroxyl radical scavenging capacities of the bean extracts at 50 and 100 ppm were 12% to 29% and 32% to 49%, respectively. All extracts used prevented human low-density lipoprotein (LDL) cholesterol oxidation by 61.4% to 99.9% at 2 to 50 ppm level as catechin equivalents.     

Physicochemical,technological and sensory characteristics of a rice (Oryza sativa L.) and bean (Phaseolus vulgaris L.) soup prepared by extrusion

The aim of this work was to prepare and evaluate an instant soup formulated with broken rice and beans processed by thermoplastic extrusion using a pilot‐scale, single‐screw extruder. The final product was characterised regarding its physicochemical composition, amino acid profile, functional–technological properties and sensory performance. The extrusion parameters were set using three extrusion zone temperatures (30, 40 and 70 °C), a screw speed of 177 rpm, feed rate of 260 g min^?1. and circular matrix of 3.85 mm. The final product contained considerable levels of protein (12.91 g per 100 g) and dietary fibre (8.07 g per 100 g). Amino acid profile analysis showed that only sulphur‐containing amino acids and tryptophan were limiting with the remaining present in adequate concentrations to meet children's requirements. Regarding functional and technological properties, the instant soup powder showed appropriate water solubility and water absorption indexes as expected. The soup sensory analysis indicated good acceptability, with a purchase intent index of 71%.     

Phytate Reduction in Brown Beans (Phaseolus vulgaris L.)

Brown beans (Phaseolus vulgaris L.) were subjected to treatments to evaluate effects of pH, temperature, CaCl₂, tannase and fermentation on degradation of phytate. Soaking was performed at 21°C, 37°C and 55°C at pH 4.0, 6.0, 6.4, 7.0, and 8.0. Optimal conditions for phytate degradation were pH 7.0 and 55°C. After soaking 4, 8 or 17 hr at these conditions 79%, 87% and 98% of phytate was degraded, respectively. Addition of tannase enhanced reduction of phytate. Fermentation of presoaked whole beans resulted in reduction of 88% of phytate after 48 hr.     

Impact of transglutaminase treatment on properties and in vitro digestibility of white bean (Phaseolus vulgaris L.) flour

Common beans (Phaseolus vulgaris L.) are rich in nutrients and have significant amounts of proteins and complex carbohydrates, besides to be rich in unsaturated fatty acids and dietary fibres. Consumption of beans could be improved by processing them into flour. In this study the effect of microbial transglutaminase (TG) on the structure, physical (colour parameters, moisture, water holding capacity), thermal properties and in vitro digestion of undehulled (WB) and manually dehulled (SB) flour samples from white common beans (P. vulgaris L.) was evaluated. Flour samples were incubated in the absence and presence of TG (WB/TG and SB/TG). We observed that the enzyme is able to catalyse the formation of polymers, suggesting that the proteins occurring in the bean flour act as TG substrates. Microstructure of samples was examined by Scanning Electron Microscopy (SEM), while thermal properties were studied by Differential Scanning Calorimetry. Microstructural results showed that the TG-treated samples possess a more compact structure, made of starch granules surrounded by proteins that, presumably, contain TG-catalysed polymers. Moreover, TG treatment had a major impact on colour, water holding capacity (WHC) and thermal properties. In particular, WB and SB samples presented a darker colour than WB/TG and SB/TG samples, while the latter showed reduced WHC that was only 30% and 37% of WB and SB samples, respectively. The transition enthalpy (ΔH) in the temperature range from 57 to 70 °C (WB, WB/TG) and from 60 to 68 °C (SB, SB/TG) followed the order: WB/TG > WB and SB/TG > WB, respectively. In vitro digestion experiments indicate that the presence of isopeptide bonds decreased the digestibility of TG-treated flour samples.     

酰化对芸豆分离蛋白热学特性的影响研究

从参与酰化反应基团的视角,运用热分析(DSC)技术,研究了不同酰化阶段芸豆分离蛋白热学性质的变化规律。芸豆分离蛋白(KPI)的酰化过程存在两个主要的酰化阶段,酸酐-蛋白比为0～0.1(乙酰化)和0～0.2(琥珀酰化)g/g,为ε-氨基(Lys)酰化阶段(N-酰化);再增加酸酐与蛋白比,ε-氨基酰化基本完成,反应进入羟基(Thr,Ser)酰化阶段(O-酰化)。在N-酰化阶段,琥珀酰化诱导KPI的热稳定性增加,而焓变(ΔH)略有降低,乙酰化不影响KPI的热稳定性和焓变(ΔH);羟基酰化阶段,酰化导致KPI变性温度(Td)降低,伴随焓变(ΔH)急剧下降。