Isolation of velvet bean (Mucuna pruriens) starch:: Physicochemical and functional properties

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 mum, granules having an oval shape. Paste properties were: gelatinization temperature, 74.82 degreesC; gelatinization temperature range, 70-80 degreesC; 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 degreesC, 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.