Physicochemical properties of native Jack bean (Canavalia ensiformis) starch: An underutilised legume

Abstract

Legumes are a cost-effective source of proteins and abundant starch, a biodegradable substance, providing human nutrition and serving various food sectors globally. Some of the neglected (underutilised) legumes can also be used as the cheapest source of starch. Therefore, the present study was conducted to determine the physicochemical characteristics of jack bean (Canavalia ensiformis) starch - a legume not widely known so underutilised. The starch was isolated from the bean by standard method to study its various properties. One-way analysis of variance was employed to verify a significant difference at the 5% significance level. The jack bean yielded 30.98% of starch. The starch’s moisture, ash, fat, protein, fiber, and carbohydrate content were 9.67%, 0.19%, 0.27%, 0.56%, 0.27%, and 89.28% respectively. The physicochemical properties were also determined. The apparent and total amylose contents were 43.82% and 47.78%, respectively, with 7.66% of amylose leaching at 95°C. The water and oil absorption capacities were 2.31 and 2.56 g/g, respectively, while emulsion capacity and stability were 62.30 and 71.38 %, respectively. The solubility and swelling power of jack bean starch increased with temperature from 55 to 95°C. The effect of starch concentrations (6, 8, and 10%) on freeze-thaw stability revealed that water expelled decreased as starch content increased. Nevertheless, a comprehensive investigation has not been conducted into the distinct functional characteristics and other attributes of jack bean starch. This study could provide new opportunities for conventional starch industries that rely on starch from sources like cereals, tubers, and rhizomes.