Physicochemical characterization of starch extracted from Malaysian wild yam (Dioscorea hispida Dennst.)

Abstract

Using a sedimentation method, the extracted starch from Dioscorea hispida tuber was characterized for their morphological, thermal and other physicochemical properties such as total starch content, moisture content, pH, water binding capacity (WBC), solubility and swelling power. The starch content extracted from the tuber was 11.46% with the WBC and moisture content were 107% and 249% respectively. Results showed the starch solubility and swelling power gradually increased with the increasing of temperature ranging from 65°C to 95°C. Under a scanning electron microscope (SEM), it was observed the starch granules have polyhedral shapes and their size between 1.3 μm to 4.3 μm. The results obtained from differential scanning calorimeter (DSC) showed the starch transition temperature (To, Tp and Tc) were 74.54°C, 79.35°C and 83.36°C whereas, enthalpy of gelatinization (ΔHgel) was 4.12 Jg-1. This research identify that starch from D. hispida has unique properties which can be used as a new starch source for various applications.