Gelation,thermal and pasting properties of pigeon pea (Cajanus cajan L.), dolichos bean (Dolichos lablab L.) and jack bean (Canavalia ensiformis) flours

This study evaluated the rheological, thermal and pasting properties of pigeon pea (PP), dolichos bean (DB) and jack bean (JB) legume flours and gels. Starch and protein contents were also measured and its molecular weight distribution was determined by electrophoresis. PP and DB showed the highest viscosities while JB had the highest pasting temperature. The minimum flour concentrations for gel formation were estimated at 6–8% for DB and PP and 10% for JB. Above these concentrations all flour suspensions heated to 95 °C led to gels with a solid-like behavior. Differential scanning calorimetry showed two endothermic peaks in all flours at 80–89 °C and 96–100 °C. Avrami model was successfully fitted to the hardening kinetics of PP and DB gels stored at 4 °C. The half-life times were 22 and 6 h for PP and DB respectively. PP and DB flours were able to form self-supporting gels and could be applied in the formulation of gel-like foods.     

Composition and functional properties of raw and heat processed velvet bean (Mucuna pruriens (L.) DC. var utilis) flours

Summary The proximate composition and functional properties of raw and heat-processed velvet bean (M ucuna pruriens (L.) DC. var utilis ) flours were studied. The flours were prepared by soaking raw beans for 14 h, boiling for 30 min (heat-processed), manual dehulling, oven-drying (65 °C) and milling. The heat-processed flour contained 6.8% moisture, 24.3% protein, 4.9% fat, 1.3% crude fibre, 3.5% ash and 61.2% carbohydrate. The flour was rich in potassium (125 mg/100 g), zinc (9.8 mg/100 g) and phosphorus (361 mg/100 g). Differences in proximate and mineral composition of raw and heat-processed flours were not significant. The flours showed minimum protein solubility at pH 4.5 and formed reasonably stable emulsions and foams. Compared to raw flour, heat-processed flour had better water and fat absorption capacities, but lower protein solubility, emulsion and foam capacities. The flours have potential for food product development.     

Effect of extrusion cooking on structure and functional properties of pea and kidney bean proteins

Pea (Pisum sativum L cv Ballet) and kidney bean (Phaseolus vulgaris L cv Pinto) seeds were extruded at 148 and 156 °C respectively. Protein solubility at various pH values and in various solvents was determined and analysis of protein fractions was carried out by SDS‐PAGE. Also, sulphhydryl and disulphide groups, water‐holding capacity (WHC), water solubility index (WSI) and oil absorption capacity (OAC) were determined. No changes in total nitrogen content of pea and kidney bean seeds occurred as a result of thermal treatment. Protein solubility from raw and extruded legumes was significantly higher in saline solutions than in water in the pH range 2–10. The solubility of proteins from extruded pea and kidney bean flours was greatly decreased with respect to native flours when extraction was in buffer (pH 7.0) alone. Extraction with buffer containing 2‐mercaptoethanol (2‐ME) or sodium dodecyl sulphate (SDS), alone or in combination, greatly increased protein extractability. As a result, the relative solubility was nearly 100% in buffer with SDS and 2‐ME for both raw and extruded samples. Total and free sulphhydryl group and disulphide contents decreased significantly (P < 0.05) after extrusion cooking. Moreover, extrusion treatment caused major changes in the band patterns of the albumin and globulin fractions obtained by SDS‐PAGE. WHC and WSI of extrudates increased significantly in both peas and kidney beans. A significant reduction in OAC was observed in extruded kidney bean flour. © 2000 Society of Chemical Industry     

Bioactive phenolic compounds and functional properties of dehydrated bean flours

The impact of soaking, cooking, and industrial dehydration on the phenolic profile, antioxidant activity, and functional properties of two bean varieties (Cannellini and Pinta) was investigated. HPLC-PAC and HPLC-MS (ESI) analysis identified phenolic acids (44% and 41% of the total of identified phenolics, respectively) as the main phenolic compounds in raw Cannellini flour and catechins and procyanidins (63%) in raw Pinta flour. As a result of the industrial dehydration, a general reduction of these bioactive compounds and antioxidant activities (ORAC) was observed; however, their levels were still relevant in dehydrated bean flours. The raw and processed flours exhibited low oil holding capacity (1.00-1.15 mL/g), whereas water-holding capacities rose to 3.0-3.8 mL/g. Emulsifying activities and foaming capacities were inhibited during thermal processing. Thus, the significant occurrence of bioactive phenolic compounds, the relevant antioxidant capacities along with the interesting functional properties of dehydrated bean flours make them to be considered functional ingredients for food formulation.     

Enzymatic hydrolysis of hard‐to‐cook bean (Phaseolus vulgaris L.) protein concentrates and its effects on biological and functional properties

Inadequate postharvest handling and storage under high temperature and relative humidity conditions produce the hard‐to‐cook (HTC) defect in beans. However, these can be raw material to produce hydrolysates with functional activities. Angiotensin I‐converting enzyme (ACE) inhibitory and antioxidant capacities were determined for extensively hydrolysed proteins of HTC bean produced with sequential systems Alcalase‐Flavourzyme (AF) and pepsin–pancreatin (Pep‐Pan) at 90 min ACE inhibition expressed as IC₅₀ values were 4.5 and 6.5 mg protein per mL with AF and Pep‐Pan, respectively. Antioxidant activity as Trolox equivalent antioxidant capacity (TEAC) was 8.1 mm  mg^?1 sample with AF and 6.4 mm  mg^?1 sample with Pep‐Pan. The peptides released from the protein during hydrolysis were responsible for the observed ACE inhibition and antioxidant activities. Nitrogen solubility, emulsifying capacity, emulsion stability, foaming capacity and foam stability were measured for limited hydrolysis produced with Flavourzyme and pancreatin at 15 min. The hydrolysates exhibited better functional properties than the protein concentrate.     

红豆预熟化工艺及理化性质的研究

针对红豆种皮厚、难以煮熟等特点，通过“微波预处理–浸泡–蒸煮”的预熟化技术开发出一款能与大米同煮同熟的红豆产品。在利用响应面法优化预熟化工艺的基础上，对不同糊化度预熟化红豆的外观、色泽、糊化特性、质构和复煮特性进行测试。结果表明：微波时间、微波功率、浸泡时间、蒸煮时间的增加均会显著提升红豆的糊化度。与原料红豆相比，预熟化红豆的色泽变暗、体积膨大数倍、硬度降低、糊化粘度降低、复水性增加7.5～8.8倍，且模拟白米蒸煮条件复煮后无白芯。但随着糊化度的增加，红豆颗粒吸水膨胀、表皮破裂严重、感官分数下降、复水性先增加后降低。综上，优化预熟化最佳工艺为：微波功率640 W，微波时间30 s，浸泡时间6.5 h，蒸煮时间20 min，所得预熟化红豆的糊化度约为57.52%。     

Effect of genotype on the physicochemical and functional attributes of faba bean (<Emphasis Type="Italic">Vicia faba</Emphasis> L.) protein isolates

The functionality and surface characteristics of protein isolates prepared from seven genotypes of faba bean were investigated. All factors studied were independent of genotype. The average protein and isolate (~94% protein) yields were ~77% and ~25%, respectively, using an alkaline extraction process followed by isoelectric precipitation. The overall averages were: surface charge +22.1 mV, surface hydrophobicity 47.2 arbitrary units, and surface and interfacial tensions of 65.0 mN/m and 10.7 mN/m, respectively. The ratio of the major globulin fractions (legumin:vicilin) shifted from 3.8 for the flours to 4.5 in the isolates. Average values for foaming capacity and stability, emulsion capacity, creaming stability, oil holding capacity, emulsifying activity and stability indices, and solubility were 162.0%, 65.0%, 184.0 g/g, 94.0%, 5.7 g/g, 13.0 m²/g, 10.7 min, and 81.0%, respectively. The lack of significant varietal effects would be advantageous to food processors as the source of the feedstock would not affect ingredient functionality.     

Effect of hydrothermal treatment of runner bean (Phaseolus coccineus) seeds and starch isolation on starch digestibility

The study investigated the effect of traditional soaking and cooking, storage after cooking and freezing (? 18 °C, 21 days) and autoclaving of two varieties of runner bean on starch digestibility. Results achieved were compared with digestibility of isolated starch subjected to similar treatments. The digestibility of native starch from Nata var. seeds was lower after isolation than in raw flour. This starch was characterized by a higher content of fat and lower values of swelling power (SP) and amylose leaching (AML). After the thermal treatment, a significantly higher content of rapidly digestible starch (RDS) was observed both in seeds and starch. It was accompanied by reduced contents of resistant starch (RS) and slowly digestible starch (SDS). In flours from cooked seeds, the content of RDS was observed to be higher than in flours from autoclaved seeds, despite similar changes in contents of other constituents (ash and protein). It was probably due to better starch gelatinization owing to the long-lasting soaking of seeds. This resulted in a greater decrease of amylose content of starch compared to the other flours. Differences in SP, AML and thermal properties between starches isolated from two bean varieties had no influence on their digestibility after cooking. The storage of starch pastes at a temperature of ? 18 °C, unlike that of seeds, resulted in a significant increase in RS content, which shows the importance of other flour components in the process of starch retrogradation.     

绿豆萌发过程中绿豆蛋白的功能特性及其抗氧化性

本文以绿豆为材料,研究了其萌发过程中绿豆蛋白的功能特性(溶解性、持水性、持油性、乳化性、起泡性、乳化稳定性、起泡稳定性)及抗氧化性(DPPH自由基清除率、金属离子螯合率、超氧阴离子自由基清除率)的动态变化。结果表明,随着萌发时间的不断延长,绿豆蛋白的溶解性、持水性、持油性、乳化性、起泡性均呈现先增加后降低的趋势,乳化稳定性和起泡稳定性得以增强。其中,溶解性萌发24 h时达到最高,萌发96 h最低;萌发的绿豆蛋白持水性、持油性和乳化性相对于未萌发的分别提高了1.57倍、4.13倍和2.47倍;乳化稳定性、起泡性和起泡稳定性较未萌发的分别提高了43.8%、46.6%和61.3%。此外,萌发过程中的绿豆蛋白抗氧化性呈现先升高后下降的趋势,萌发促进了绿豆蛋白的抗氧化性。其中,DPPH自由基清除率和金属离子螯合率均在绿豆萌发36 h达到最大,较未萌发的分别提高了73.8%和31.0%;超氧阴离子自由基清除率萌发48 h达到最大,较未萌发的提高了81.7%。随着绿豆萌发时间的延长,绿豆蛋白的功能特性和抗氧化性呈现先升高后下降的趋势,萌发中期(24~48 h)达到最大。因此,萌发提升了绿豆蛋白的功能特性和抗氧化性,扩大了其在食品加工中的应用,提高了其利用价值。     

Physical and functional characteristics of selected dry bean (Phaseolus vulgaris L.) flours

Many varieties of dry beans (Phaseolus vulgaris L.) are available with entirely different physico-chemical and sensory characteristics. Selected dry bean varieties (red kidney, small red kidney, cranberry and black) were processed into flour and analyzed for the physico-chemical and functional characteristics. The bulk density of the beans flours varied significantly (p < 0.05) from 0.515 g/ml for black bean flour to 0.556 g/ml for red kidney bean flour. The small red kidney bean flour had the highest water absorption capacity (2.65 g/g flour) while black bean flour showed the lowest at 2.23 g/g flour. Significant differences were observed for oil absorption capacities of bean flours, which ranged from 1.23 g/g for small red kidney bean flour to 1.52 g/g for red kidney bean flour. The bean flours emulsion capacity and stability and foaming capacity and stability also varied significantly and was variety-dependent. The highest apparent viscosity, 0.462 Pa.s, was recorded for small red kidney bean flour whereas black bean flour exhibited the lowest value of 0.073 Pa.s at 30 g/100 ml water content in the flour dispersions. The force-deformation curves for doughs from different bean flours showed that black bean flour had the highest peak force or hardness value of 90.7 N followed by doughs from cranberry, small red kidney and red kidney bean flours. The results of this study offer useful data on bean flours' potential uses in different food products.     

Physicochemical,nutritional and functional properties of marama bean flour

Marama bean is a protein-rich, underutilised, drought-tolerant legume in sub-Saharan Africa. Its utilisation may be increased through value addition into protein-rich flours. Defatted flour from unheated and dry-heated (150 °C/20 min) whole marama beans (UMF and HMF) were analysed for physicochemical and protein-based functional properties. Heating significantly increased in vitro protein digestibility of marama bean flour. Of functional importance are the high levels of tyrosine present in marama bean flours. Heating significantly reduced protein solubility and emulsifying capacity of marama bean flours whilst water absorption capacity was improved. Foaming capacity was not affected by heating. UMF could be useful in food systems requiring high emulsifying capacity, but would not be suitable for applications requiring high water absorption and foaming capacity. Due to its high protein contents, marama bean flour could be used to increase the protein quality of cereal-based foods to help alleviate protein-energy nutrition in the region.     

Natural fermentation of lentils. Functional properties and potential in breadmaking of fermented lentil flour

The effects of fermentation on functional properties of lentil flour and rheological properties of doughs and breads produced from blends of wheat and fermented lentil flour were studied. Lentil protein solubility was higher at neutral pH than acid pH; the lowest and highest protein solubility values were observed at pH 4.0 and pH 7.0, respectively. Water hydration capacity and fat binding capacity of fermented lentil flour (FLF) were always higher than those of non-fermented lentil flour (NFLF), irrespective of fermentation temperature (28–42°C) and flour concentration (79–221 g/l). Emulsifying properties of NFLF were similar to the properties of other legume flours in the range used in experiment. In contrast, the emulsion capacity and stability of FLF were very low and flours fermented at 42°C did not even form emulsion. Rheological properties of doughs made from wheat-fermented lentil blends were similar to those from wheat flour with the addition of other legume flours such as pea and bean. Good quality breads were produced at 2.5 to 10% NFLF and FLF supplementation (except for bread with 10% FLF addition which was middle quality).     

Functional properties and microstructure of cowpea cultivated in north-east Argentina

The goal of this work was to analyze the effect of different treatments on functional properties (Color parameters, water holding capacity, oil holding capacity, water imbibition capacity, protein solubility and apparent viscosity) and microstructure of three cowpea varieties. Proteins present in flours obtained from heat-treated seeds exhibited a significant increase in water and oil absorption values, water imbibition capacity, and apparent viscosity, whereas solubility decreased. Color determinations on flours showed a reduction in L* and H*, and an increment in C* with treatment intensity. Structural changes in seeds would explain the variations in the functionality of flours. This study shows that cooking and autoclaving affect significantly the functional properties of flours, while soaking had a lower impact. The knowledge about these changes will be very useful for developing and obtaining new preparations based on cowpea flour.     

Physicochemical and functional properties of whole legume flour

The physicochemical, functional and pasting properties of whole flours from pinto bean, lima bean, red kidney bean, black bean, navy bean, small red bean, black eye bean, mung bean, lentil and chickpea were investigated. Significant differences in physicochemical characteristics and functional properties were observed (P < 0.05). Bulk densities, water absorption indices, water solubility indices, oil absorption capacities, emulsion activities, and emulsion stabilities ranged from 0.543 g/mL to 0.816 g/mL, 4.09 g/g to 6.13 g/g, 19.44 g/100 g to 29.14 g/100 g, 0.93 g/g to 1.38 g/g, 61.14%–92.20%, and 84.15%–96.90%, respectively. Phaseolus legume flour exhibited higher water absorption capacity, oil absorption capacity, emulsion activity, and emulsion stability compared with other kinds of legume flour. Pasting properties were significantly different (P < 0.05). Pasting temperatures and the peak, final, and setback viscosities of the flours ranged from 73.2 °C to 83.0 °C, 96.2 RVU to 216.8 RVU, 118.5 RVU to 243.8 RVU, and 28.3 RVU to 103.2 RVU, respectively.     

Functional,biochemical and pasting properties of extruded bean (Phaseolus vulgaris) cotyledons

Response surface methodology was used to investigate the effects of extrusion conditions – namely moisture content (12.3–23.7 g 100 g^?1) and temperature (150–178 °C) – on physicochemical, antinutritional compounds, functional and pasting properties of extruded bean cotyledons. Results indicated that extrusion cooking did not change the chemical composition of bean flours, but completely eliminated the activity of the trypsin and α‐amylase inhibitors and haemagglutinins. The extrusion significantly improved starch and protein digestibility, water solubility and absorption of bean cotyledon. In addition, extrusion conditions significantly affected pasting properties, resulting in extrudate flours with different peaks and final viscosity values. From the results obtained in this work, it is possible to design a product with specific physicochemical, functional and nutritional properties using the appropriate moisture and temperature during extrusion.     

On the functional properties of globulin and albumin protein fractions and flours of African locust bean (Parkia biglobossa)

Albumin (ALBa) and globulin (ALBg) fractions of African locust bean were isolated and the functional properties were compared with its defatted (ALBdf) and undefatted flours (ALBf). Albumin had minimum % solubility (56.7%) at pH5, while minimum solubility was observed at pH4 for globulin and the flours. In all the samples studied, maximum solubility was observed at pH 10. A pH-dependent gelation study revealed that all of the samples had the highest least gelation concentration at pH10 apart from ALBf which had 16% w/v LGC at pH 2. Initial increase in ionic strength of the medium, to 0.4 and 0.6 M, enhanced the gelation capacity of protein fractions and flours, respectively, while further increase in ionic strength reduced it. Oil absorption capacity was maximal in ALBa while ALBf had the least value of 1.05 ml/g. Initial increase in ionic strength, up to 0.4 M, increased the water absorption capacity (WAC) of albumin fractions while WACs of the globulin fraction and flours were reduced when the ionic strength of the media reached 0.4 M. Foam capacity increased as the concentration of protein solution increased but was reduced by 6% w/v in ALBf. Initial increase in ionic strength enhanced both foam capacity and stability. Maximum EA was observed at pH 10 in all samples apart from ALBf, which reached a peak EA value at pH 2. ES (emulsion stability) was maximal at pH 10 for ALBa and ALBg while the same values were observed for ALBdf and ALBf at pH 2 and 10. Increasing the ionic strength, to 0.4 M, enhanced the EA and ES of ALBa while further increase in ionic strength, to 0.7 M, improved EA of ALBf but reduced the ES. Both EA and ES of ALBf reached peak values in 0.2 M solutions but no fixed pattern was observed in the response of ALBdf to various ionic strengths of the solutions.     

Effect of industrial process conditions of fava bean (Vicia faba L.) concentrates on physico-chemical and functional properties

Fava bean (Vicia faba L.) is a promising source of proteins and has a potential in industrial food applications. Processing of fava ingredients modifies proteins and their functional properties. This study established the complexity of the relationship between fava protein-associated reactions (protein hydrolysis and aggregation), physico-chemical properties (electric charge, solubility, and intrinsic fluorescence, thermal integrity) and functional properties (foam and emulsion). For this study, an air-classified fava protein concentrate (65% w/w protein d.b.) was processed using pH (2, 4, 6.4 and 11), temperature (55, 75 and 95 °C) and duration of treatment (30 and 360 min) to produce 36 modified fava concentrates. Processing resulted in protein hydrolysis at pH < 4, and protein aggregation at pH ≥ 6.4 at temperatures above 75 °C, which influenced foaming and emulsification distinctly owing to the differences in their stabilizing mechanisms. Despite these modifications, their physico-chemical and functional properties were primarily governed by the beverage application pH. The surprising interplay shown between properties encourages the need to dive further into the different protein/non-protein reaction and interactions that can occur in fava concentrate.Industrial relevanceThe functionalities of fava bean protein-rich ingredients were investigated in industrial beverage application systems (pH 4 and 7) after industrial relevant process conditions (pH: 2, 4, 6.4 and 11; temperature: 55, 75 and 95 °C, treatment duration: 30 and 360 min). Foam capacity (>100%) was very high for all ingredients at both pH applications (acidic or pH 4, and neutral or pH 7), while the foam stability changed according to the application pH. So-called foam-breakers were discovered in acidic application, while all ingredients maintained high stability in neutral applications. A similar instability was found for emulsification, since emulsion made with all ingredients in acidic application creamed immediately after production. Emulsions in neutral applications were homogenous with all ingredients, thus, emulsion capacities were equivalent to each other, but the storage stability was affected by the ingredient processing pH.     

Nutrient and functional properties of composite flours processed from pregelatinised barley,sprouted faba bean and carrot flours

Mixture response surface methodology was used to study the effects of blending ratio (barley, faba bean and carrot) and faba bean sprout durations (1, 2 and 3 days) to improve nutrients and functional properties of bassoo (a traditional food in Ethiopia). Addition of sprouted and roasted faba bean and dried carrot flours significantly (P < 0.05) increased iron, zinc, total carotenoid (TC), water solubility index (WSI), water hydration capacity (WHC) and a_w. Models generated were fitting with high coefficient of determination R²: 0.74, 0.94, 0.99, 0.99, 0.94, 0.94, 0.94, 0.96 and 0.99 for iron, zinc, TC, condensed tannin, ferric reducing power, a_w, WAI, WSI and WHC, respectively. The study showed blending of pregelatinised barley, sprouted and roasted faba bean and dried carrots flours from 50% to 65%, 25% to 35% and 10% to 15%, respectively, led to achieve desired functional and nutritional quality studied.     

The impact of processing on phytic acid,in vitro soluble iron and Phy/Fe molar ratio of faba bean (Vicia faba L.)

BACKGROUND: Faba bean is one of the important legumes in Asian countries. It is also a major source of micronutrients in many rural areas. Unfortunately, the bioavailability of iron from faba bean is low because it is present as an insoluble complex with food components such as phytic acid. The influence of soaking, germination and fermentation with the expectation of increasing the bioavailability of iron was investigated. RESULTS: Fermentation treatments were most effective in decreasing phytic acid (48–84%), followed by soaking at 10 °C after preheating (36–51%). Steeping faba beans for 24 h at 25 °C had the least effect on the removal of phytic acid (9–24%). With increased germination time at 30 °C, phytic acid progressively decreased from 9 to 69%. Most wet processing procedures, except soaking after wet preheating, caused losses of dry matter and iron (8–15%). In vitro iron solubility, as a percentage of total iron in soaked faba bean after dry preheating, was significantly higher than in raw faba bean (P < 0.05). Fermentation and germination did not have significant effects on the solubility of iron. CONCLUSION: The expected improvement of iron bioavailability levels due to lower phytic acid was not confirmed by increasing levels of in vitro soluble iron. Soaking, germination and fermentation can decrease phytic acid in faba bean. However, results from in vitro solubility measurement of iron showed little improvement of iron bioavailability in fermented and germinated faba beans over untreated raw faba beans (P < 0.05). It seems that componets of dietary fibre other than phytic acid are more important in binding iron. Probably, a complex association between dietary fibre and iron is the reason for the poor bioavailability of iron in faba bean. Copyright © 2009 Society of Chemical Industry     

Effects of pretreatment and drying methods on molecular structure,functional properties and thermal stability of fibre powder exhibiting colour from Centella asiatica L.

Effects of pretreatment and drying methods and particle size on characteristics of fibre powder from Centella asiatica L. leaves were investigated. Thermal stability of oil‐based colour solutions was also assessed. Steaming and combined steaming and alkaline soaking resulted in the powder with more greenness and higher chlorophylls contents, while combined steaming and acid soaking yielded dark yellow powder with lower chlorophylls contents. Chemical soaking led to the powder with decreased water holding capacity and solubility. Vacuum‐drying reduced chlorophylls degradation, hence retention of the greenness of the powder. Increased particle size resulted in decreased lightness of the powder, but in increased lightness of the solutions; water and oil holding capacities of the powder increased with the particle size. Fourier transform infrared (FTIR) spectra and X‐ray diffraction (XRD) patterns of the powder corresponded to its colour and functional property changes. Colour of the solutions changed only slightly upon heating at 80 and 180 °C for 1 h.