Isolation of Velvet Bean (Mucuna pruriens) Starch: Physicochemical and Functional Properties

Abstract

The velvet bean (Mucuna pruriens) is an excellent potential starch source as it contains approximately 52 % of this carbohydrate. The physicochemical and functional properties of velvet bean starch were evaluated and compared to those of other starches. The chemical composition was: moisture 10.78 %; solid matter: protein 0.71 %; fiber 0.54 %; ash 0.28 %; fat 0.40 %; starch 98.1 %; and phosphorus 0.015 %. Amylose content was higher (39.21 %) than in tuber and cereal starches but similar to other legume starches. Average granule size was 23.6 μm, granules having an oval shape. Paste properties were: gelatinization temperature, 74.82 °C; gelatinization temperature range, 70—80 °C; and alkali number, 3.22. Gels produced with velvet bean starch were firmer than those produced with corn starch, and had a higher degree of retrogradation, even at high concentrations. At 90 °C, solubility was 16.2 % and swelling power was 16.17 g of water/g of starch. Given these properties, velvet bean starch has potential applications in food products requiring high temperature processing, such as jams, jellies and canned products.