Hydration Kinetics of Red Kidney Beans (Phaseolus vulgaris L.)

Soaking of dry red kidney beans was studied at 20, 30 40 and 60°C by the method of weight gain until equilibrium conditions were attained. Water absorbed during soaking was a function of both soaking time and temperature. Soaking at high temperatures increased the hydration rate constant and decreased soaking time to achieve equilibrium. Compared to unblanched beans, the application of a pre-blanching step considerably reduced hydration times of blanched beans. Due to the plasticity effect acquired upon blanching, blanched beans showed a significantly high hydration rate constant and exhibited a more constant equilibrium moisture content regardless of soaking temperature. Activation energy values (E_a) of the hydration process were 6.48 Kcal/mole for blanched and 14.25 for unblanched beans.     

Thermal Effects on Net Protein Ratio of Red Kidney Beans (Phaseolus vulgaris L)

Net protein ratio (NPR), predicted-protein efficiency ratio (P-PER), relative NPR (RNPR), and corrected RNPR (CRNPR) of thermally processed red kidney beans were estimated in rats and compared to in vitro protein digestibility-corrected amino acid score (AAS_IVDP), and computed-protein efficiency ratio (C-PER). Thermal processing had a significant effect on protein intake, NPR, P-PER and CRNPR values of beans. Changes in protein intake suggest that heat processing had an effect on the palatability of the beans. Home-cooked beans and commercially canned beans had higher NPR values than beans autoclaved at 128°C for 20 min, while beans autoclaved at 121°C for 10–90 min had intermediate values. High correlation coefficients between P-PER and C-PER, CRNPR and C-PER, and CRNPR and AAS_IVDP (r=0·990, 0·992 and 0·960, respectively, P<0·001) were observed.     

Physicochemical Studies of Hard-to-Cook Beans (Phaseolus vulgaris)

Model aqueous systems were used for the study of the cooking quality of beans (Phaseolus vulgaris). These systems were created using graded contents of calcium and magnesium ions, in a ratio of 4:1, to prepare aqueous media with cation content corresponding to 0–400 mg litre^-1 of calcium carbonate. The model systems were used to measure the quality of boiled beans in water of low and high divalent cation content. A boiling time of 60 min was used and the hardness of the boiling beans was measured by an Instron Universal Testing Machine. Cooking of beans in water of low divalent cation content equivalent to 0–50 mg litre^-1 CaCO₃ resulted in well-boiled beans for both types (easy-to-cook and hard-to-cook) of beans. Boiling in water of high divalent cation content led to the formation of very hard beans for both types of bean, while boiling in water of moderate divalent cation content (normal drinking water: 150–250 mg litre^-1 CaCO₃) differentiated between the two categories of beans. These results were further tested by adsorption experiments with divalent cations, on beans boiled (a) in different proportions of boiling water, and (b) in model aqueous systems. The divalent cation content of boiling water and the phytic acid content of the beans proved to be the crucial factors in the hard-to-cook phenomenon of beans. © 1997 SCI.     

Effects of Calcium, Sucrose, and Aging on the Texture of Canned Great Northern Beans (Phaseolus vulgaris, L.)

Factors affecting hardness of canned Great Northern beans (Phaseolus vulgaris, L.) were investigated. Addition of calcium significantly increased the hardness of processed beans; however, the calcium content usually found in hard culinary water supplies did not cause good quality beans to be unacceptably hard when processed. Firmer processed beans had a higher calcium uptake and lower water absorption. Sucrose increased the hardness of processed beans. Sucrose and calcium were synergistic in their firming action. Beans stored at high temperature and humidity for a prolonged period of time became firmer when processed and more sensitive to calcium hardening and to the synergistic effects of calcium and sucrose.     

Iron Speciation in Beans (Phaseolus vulgaris) Biofortified by Common Breeding

The iron storage protein ferritin is a potential vehicle to enhance the iron content of biofortified crops. With the aim of evaluating the potential of ferritin iron in plant breeding, we used species‐specific isotope dilution mass spectrometry to quantify ferritin iron in bean varieties with a wide range of total iron content. Zinc, phytic acid, and polyphenols were also measured. Total iron concentration in 21 bean varieties ranged from 32 to 115 ppm and was positively correlated with concentrations of zinc (P = 0.001) and nonferritin bound iron (P < 0.001). Ferritin iron ranged from 13% to 35% of total iron and increased only slightly in high iron beans (P = 0.007). Concentrations of nonferritin bound iron and phytic acid were correlated (P = 0.001), although phytic acid:iron molar ratio decreased with increasing iron concentration (P = 0.003). Most iron in high iron beans was present as nonferritin bound iron, which confirms our earlier finding showing that ferritin iron in beans was lower than previously published. As the range of ferritin iron content in beans is relatively narrow, there is less opportunity for breeders to breed for high ferritin. The relevance of these findings to the extent of iron absorption depends on resolving the question of whether ferritin iron is absorbed or not to a greater extent than nonferritin bound iron.     

Influences of Soaking Temperature and Storage Conditions on Hardening of Soybeans (Glycine max) and Red Kidney Beans (Phaseolus vulgaris)

The influences of soaking treatment and storage conditions on the softening of cooked beans, namely, soybeans and red kidney beans, were investigated. It was revealed that the softening of fresh soybeans and fresh red kidney beans was suppressed during subsequent boiling after soaking treatment at 50 and 60 °C. Furthermore, in treated aged soybeans and red kidney beans that were subjected to storage at 30 °C/75% relative humidity for 6 mo and soaking treatment at 50 to 60 °C, the hardness during cooking was further amplified. This suggested that the mechanism of softening suppression differs depending on the influences of soaking and storage. Analysis of the pectin fraction in alcohol insoluble solid showed insolubilization of metal ions upon storage at high temperature and high humidity in both soybeans and red kidney beans, which suggests interaction between Ca ions and hemicellulose or cellulose as cell wall polysaccharides. The results of differential scanning calorimetry (DSC) showed that aged soybeans exhibited a shift in the thermal transition temperature of glycinin‐based protein to a higher temperature compared with fresh soybeans. From the results of DSC and scanning electron microscopy for aged red kidney beans, damaged starch is not conspicuous in the raw state after storage but is abundant upon soaking treatment. As for the influence of soaking at 60 °C, it can be suggested that its influence on cell wall crosslinking was large in soybeans and red kidney beans in both a fresh state and an aged state.     

Roasting of Navy Beans (Phaseolus vulgaris) by Particle-to-Particle Heat Transfer

A rotating chamber dry roaster using pre-heated ceramic beads as heat transfer media was used to roast navy beans. Processing conditions were: beads temperature, 240 and 270°C; bean-to-bead ratio, 1/10 and 1/15 and contact times of 1 and 2 min. Product temperatures achieved ranged from 92–125°C for the eight runs. Heat transfer coefficients varied from 3.6–23.4 W/(m²) (°C). Roasted products showed reduced water-soluble nitrogen content and gel forming capacity, increased water-holding capacity and cold paste viscosities, and no changes in available lysine and degree of starch damage. Residual trypsin inhibitor (TIA) and hemagglutinin activity varied from 92 to 22%, and 48 to 1%, respectively. A correlation was found to exist between nitrogen solubility index and TIA of products. Roasting caused fracture and separation of hulls, and facilitated their removal.     

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.     

Essential Elements and Cadmium and Lead in Fresh, Canned, and Frozen Green Beans (Phaseolus vulgaris L.)

Sixteen essential elements, cadmium and lead were determined in fresh, canned, and frozen green beans (Phaseolus vulgaris L.). Samples were taken during processing to determine where changes in element content occurred. Canned green beans contained lower concentrations of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, and zinc, but had higher amounts of chloride, nickel, and sodium than fresh beans. No change in silicon was observed. Iron, phosphorus and potassium were lower in frozen than in fresh green beans, but calcium, sodium and zinc were higher. There was no change in chloride, copper, magnesium, manganese and silicon due to freezing. Element retention ranged from 51 - 100% for canned and from 73 - 171% for frozen green beans.     

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.     

Reversibility of the Hard-to-Cook Defect in Dry Beans (Phaseolus vulgaris) and Cowpeas (Vigna unguiculata)

The hard-to-cook defect, assumed to be a permanent condition in legume seeds, can be reversed. Dry beans (Phaseolus vulgaris) and cowpeas (Vigna unguiculata) which had developed the hard-to-cook defect when stored at 29°C, 65% RH had progressively shorter cooking times after additional storage at 6.5°C, 71% RH. This would suggest that the mechanism(s) leading to development of the defect should be easily reversed. The ability to reverse the hard-to-cook defect in legume seeds would provide several economic and nutritional benefits.     

浸泡处理对红芸豆的物理性质及蒸煮品质的影响

以红芸豆为原料,探讨不同浸泡温度(25、45、65℃)对芸豆物理性质及蒸煮品质的影响。结果表明:芸豆在浸泡过程中,随着浸泡温度升高与时间延长,其吸水率、体积膨胀率、固形物溶出率等均呈增加的趋势,平衡吸水率常数则呈下降趋势;浸泡温度的提高有利于达到浸泡平衡及缩短浸泡时间。在加工性能方面,45℃下浸泡可显著缩短煮豆时间并提高煮熟红芸豆的品质。     

Isolation and Characterization of the Major Protein from Great Northern Beans (Phaseolus vulgaris)

The major protein of Great Northern beans was isolated through salt extraction, ammonium sulfate fractionation, gel filtration and DEAE-cellulose ion exchange chromatography. Physicochemical properties of the major bean protein were determined. Results from heat stability studies showed that the protein was the most stable at pH values between 4 and 6. A complete unfolding of the bean protein was not essential in order to improve its digestibility. The native protein had a compact structure and therefore was resistant to the attack by proteolytic enzymes. A glycopeptide containing a N-glycosidic protein-carbohydrate linkage, isolated from a protease digestion of the major bean protein was also characterized. Results implied that the carbohydrate moeity might have a negative influence on the digestibility of the native protein.     

Fractionation of Extracts and Crystalline and Non-Crystalline Proteins from White Kidney Beans (Phaseolus vulgaris) by Ion-Exchange High-Performance Liquid Chromatography

Sodium hydroxide solution (0.02%) and citric acid solutions (0.08N, pH 5.5, CA1; 0.60N, pH 3.5, CA2) were used to extract proteins from white kidney beans (Phaseolus vulgaris). The extracts were subjected to ion-exchange high performance liquid chromatography (IE-HPLC) using a phosphate elution buffer (20 mM, pH 7.0). The charge properties of the protein fractions present in the NaOH extract and the CA1 and CA2 extracts were similar although the relative proportion of total peak area represented by each fraction was different in the different extracts. IE-HPLC of the isoelectric precipitate (amorphous microstructure) isolated from the CA1 (bipyramidal crystalline microstructure) and the CA2 (spheroidal microstructure) extracts indicated striking differences in the charge properties of the proteins which constituted the isolates. IE-HPLC also demonstrated that the precipitation processes did not affect the charge properties of the proteins which remained after the proteins were recovered from the different extracts.     

Water-Holding Capacity in Hard-to-Cook Beans (Phaseolus vulgaris): Effect of pH and Ionic Strength

The effect of pH and ionic strength (IS) of soaking solution on the water holding capacity (WHC) of hard-to-cook (HTC) and control black beans (Phaseolus vulgaris) was evaluated. Beans were soaked 18 hr in solutions covering the pH range 1–7 at constant IS (1.0 M) or in solutions ranging in IS from 0.01 to 1.3M (prepared with either NaCl or CaCl₂) at pH 7. WHC was significantly reduced in the pH range 3.5 to 5.1 in control beans but the effect was not as pronounced with HTC samples which had a lower WHC at each pH. Solutions prepared with NaCl produced significantly lower WHC values than CaCl₂ solutions in the control but not in the HTC beans. WHC values in control beans tended to increase with higher IS, although this effect was not as apparent for HTC beans.     

Processing of Sugar-Coated Red Kidney Beans (Phaseolus vulgaris): Fate of Oligosaccharides and Phytohemagglutinin (PHA), and Evaluation of Sensory Quality

ABSTRACT:  The present study was undertaken to expand the uses of red kidney beans beyond traditional products such as sugar-coated beans—a popular snack food in many Asian countries. Beans were soaked for 12 h (initial temperature 77 °C, end temperature 24 ± 1 °C) and then cooked in boiling water (approximately 99.3 °C) for 14 min. Finally, the cooked beans were sugar-coated by dipping in 20%, 35%, or 50% sugar syrup (w/w) for 45 min at 70 °C and excess syrup was drained at the end of the process. Beans were analyzed for oligosaccharides (raffinose and stachyose) and lectins, as phytohemagglutinating (PHA) activity, at predetermined intervals during processing. A 105-member consumer panel evaluated bean quality for texture, color, sweetness, flavor, and overall acceptability. Most of the weight (81.1% of total) was gained during the 1st h of soaking. There was a significant reduction in raffinose (80.8%) and stachyose (83.4%) after 12 h of soaking. Cooking, which further reduced raffinose for a combined total of 95.8%, had no effect on stachyose. The lectins decreased by about 90% in cooked beans, with over half of inactivation occurring during soaking. On a hedonic scale of 1 to 9 (1 = dislike extremely, 9 = like extremely), all 3 bean samples scored above 5 for all the sensory attributes tested. Beans coated with 50% sugar syrup were rated best overall, with a score of 6.1. Frequency distribution of overall acceptability scores showed that 59% to 70% of the panelists rated different bean samples at a score of 6 or higher.     

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.     

Effect of Cooking on Firmness, Trypsin Inhibitors, Lectins and Cystine/Cysteine content of Navy and Red Kidney Beans (Phaseolus vulgaris)

The effect of cooking on firmness, trypsin inhibitor (TI) and lectin activities, and cystine/cysteine (Cys) of navy and red kidney beans was investigated. Beans were soaked and cooked in an open-kettle at various temperatures and periods. Navy beans canned by two methods were used for comparisons with the open-kettle cooked beans. The TI activity, lectin activity and Cys content decreased with increasing temperature and/or period. Under some of the cooking conditions, less than 5.5% and 0.1% of TI and lectin activities, respectively, were retained, though the firmness of beans was palatable. Canned navy beans did not have lectin activity but had less than 5% residual TI activity.