Abstract: Different concentrations of hydrolyzed oat starch pastes with different dextrose equivalent (DE) values prepared with thermostable α-amylase were measured for their apparent viscosity and gel strength in order to find appropriate starch paste concentrations for hydrolyzed oat starch-based fat substitutes. Apparent viscosity of hydrolyzed oat starch pastes was found to decrease as the shear rate and the temperature increased, and gel strength exhibited a downward trend with increasing DE and decreasing paste concentration. Hydrolyzed oat starch pastes at concentrations ranging from 25% to 30% were more suitable to be used in fat substitutes. Moreover, 2.39%, 2.93%, 3.73% and 4.11% were identified as appropriate DE values for hydrolyzed oat starch-based fat substitutes based on gelling point, water binding capacity, oil binding capacity, freeze-thaw stability, emulsifying capacity and emulsion stability.

Key words: oat starch, apparent viscosity, gel strength, physicochemical properties, DE value, fat substitutes