Functional properties of hydrothermally modified lesser yam (Dioscorea esculenta) starch

Abstract

Lesser yam (Dioscorea esculenta L.) is a potential starch source that can be found easily in Indonesia but has limitations in its application due to its characteristics. For this reason, native lesser yam starch was modified to improve its functional properties. The hydrothermal modification was chosen because it is safe and environmentally friendly. The hydrothermal modifications used in this research were Heat Moisture Treatment (HMT) and Annealing (ANN). This work aims to increase the use of local tubers as an alternative starch source and to study the effect of hydrothermal modification on the functional properties of lesser yam starch such as swelling power, solubility, and freeze-thaw stability. HMT was carried out using 3 moisture levels (20%, 25%, 30%) and 3 heating time levels (4h, 8h, 16h). ANN using 3 starch and water ratio levels (1:2; 1:3; 1:5) and 3 heating time levels (6h, 8h, 10h). The results indicated that swelling power and solubility decreased with the increasing moisture level in HMT and ANN in general, but have various effects in syneresis depend on moisture level and heating time. HMT modified starch prepared at 25% moisture level and 4h heating time and ANN modified starch prepared at starch: water ratio 1:3 and heating time 10h is concluded to be the best choice for food product application especially thermally stable need food product.