Chickpeas, lentils, smooth peas, mung beans, and faba beans were milled into flours and fractionated to protein and starch fractions. Compositions of the seeds, cotyledons, and flours were compared for each legume and the weight and protein recovery of each fraction analyzed. Bean curds were prepared from the protein fractions through heat denaturation of protein milk, followed by coagulation with calcium sulfate or magnesium sulfate. The effect of chickpea protein concentration and coagulant dosage on the texture of bean curds was evaluated using a texture analyzer. Textural analysis indicated that curd prepared at 2.3-3.0% protein concentration and 1.5% CaSO(4) dosage had better yield and better texture than curds prepared under other conditions. Bean curds prepared from chickpeas and faba beans exhibited the second highest springiness and cohesiveness after those from soybeans. Curds of mung beans and smooth peas, on the other hand, had the highest yields and the highest moisture contents. The protein yield of the first and second soluble extracts used for curd preparation accounted for approximately 90% of the total protein of the seeds.

We determined the relationship between textural property of legume curds and constituents of their proteins. The hardness, springiness, and cohesiveness of curds prepared from soybeans, chickpeas, and fava beans were 6.0 to 9.4 N, 0.93 to 0.95, and 0.67 to 0.77, respectively, higher than those of curds made from smooth peas, mung beans, and lentils, which were 4.2 to 4.9 N, 0.92, and 0.57 to 0.59, respectively. Soybeans, chickpeas, and fava beans had a higher proportion of 11S globulin and a lower proportion of 7S globulin than lentils, smooth peas, and mung beans. Soybeans, chickpeas, and fava beans produced a better texture of curd than did lentils, smooth peas, and mung beans, due to a higher proportion of 11S proteins.

Thermal gelation of bovine serum albumin (BSA)-sodium alginate, BSA-pectin and BSA-methyl cellulose systems in relation to binding was studied using rheological testing, turbidimetric analysis and gel filtration. Two electrostatic binding mechanisms, distinguished by particle and chain segment binding models were found in BSA-anionic polysaccharide systems. Particle binding resulted in poor gelation properties. Positive effects on gelation were found when conditions favored the chain segment binding model. Mechanisms for gelation-binding relationships were hypothesized. No evidence of binding was found in the BSA-methyl cellulose system, which generally exhibited the combined gelation properties of the individual components.

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The effect of compressing time, pH, and protein concentration on the texture of chickpea curds prepared by heat-induced gelation was assessed. The possible gelation mechanism was studied by differential scanning calorimetry (DSC), surface hydrophobicity, and viscometric analysis. Texture analysis showed that chickpea curd could be produced by steam cooking the protein fraction. DSC results indicated a decrease in the denaturation enthalpies (⌬H) for both legumin and vacilin as pH decreased from 6.5 to 6.0. Analysis of the surface hydrophobicity as a function of pH showed a sharp transition at pH 6.0. The viscosity of the protein fraction sharply increased at pH 5.2 producing an extremely hard curd. A mechanism for curd formation is proposed.