Relationships Between Selected Properties of Black Gram Seeds and Their Composition

Abstract

Seeds of different black gram varieties were evaluated for their mass, density, hydration capacity, hydration index, cooking time, and instrumental textural properties (hardness, cohesiveness, and chewiness). Starch was also isolated from these varieties and evaluated for yield, amylose content, solubility, water binding capacity, and turbidity. The pasting (pasting temperature, peak viscosity, breakdown viscosity and set back) and gelatinization (T o , T p , T c , ΔH gel, and PHI) properties of starches were measured using Rapid Visco Analyzer and Differential Scanning Calorimeter, respectively. Physico-chemical, cooking, and textural properties of seeds of different black gram varieties were related to physico-chemical, gelatinization, and pasting properties of their starches using Pearson correlation. Selected properties of black gram seeds were significantly correlated to their starches. The hardness and chewiness of cooked seeds decreased with increase in amylose content of starch (p < 0.05). The physical parameters (seed mass, seed volume, seed density), hydration capacity and cooking time of black gram seeds were positively related to the starch yield (p < 0.01). Fiber content of black gram seeds was positively correlated to the water binding capacity (WBC) of starch (r = 0.610). Seed mass and hydration capacity was positively correlated to turbidity of starch (p < 0.05). Density and hydration index of seeds was related to the pasting properties of their starches. The varieties with higher seed density and hydration index had starches with low peak viscosity and breakdown viscosity and vice-versa (p < 0.01). Hydration capacity and hydration index showed positive correlation with T c (p < 0.01). Selected instrumental textural parameters had positive correlation with ΔH gel (p < 0.01).