Physicochemical properties and digestibility of starch from bulbils of two cultivars of Dioscorea bulbifera during the growth

Abstract Starches from bulbils old from to 3 to 6 months of two cultivars of Dioscorea bulbifera were extracted and characterized in order to establish physicochemical changes during bulbils development. The results showed that sharp of starch granules was regular and ovo-triangular; the particles size analysis revealed an increasing of granules size with a unimodal distribution; granules size varied between (30 μm – 47.70 μm) for mauve cultivar and between (7.31 μm – 56.38 μm) for yellow cultivar. The chemical analysis of both cultivars showed that the starches contained low levels of lipids and ash; the protein content was nil. The functional properties such as swelling capacity and solubility increased when starches were heated in presence of water over 65°C for mauve cultivar and 70°C for yellow cultivar. Gelatinized starches from less developed bulbils were more digestible by α-amylase.