V-type granular starch prepared using aqueous-ethanol heat treatment at different ethanol concentrations

Abstract V-type granular starch (VGS) was prepared by aqueous-ethanol heat treatment at 50%, 60% and 70% ethanol. The formation process and optimal preparation conditions at each ethanol concentration were obtained, and the properties of optimized VGS were compared. The V-type crystalline structure began to form at 90, 100 and 110 °C, at 50%, 60% and 70% ethanol, respectively. VGS reached the highest cold-water viscosity and V-type crystallinity while maintaining the granular morphology when prepared with 20% starch content at 100, 130 and 140 °C at 50%, 60% and 70% ethanol, respectively. The three optimal VGS had significantly improved cold-water viscosity, adsorption capacities, and were easier to retrograde than normal maize starch. The optimal VGS formed at higher ethanol concentrations better retained granular morphology, and thus, had a greater tendency to retrograde, whereas optimal VGS formed at lower ethanol concentrations exhibited larger specific surface areas and pore volumes, and adsorbed oil better.