Acid and hydrothermal modification of different types of cassava (Manihot esculenta) starch

摘要

Starch needs to be modified for stability and better functionality if they are to be used for certain food preparation such as custard powder, jelly, baby food, glucose, thickening agent and confectioneries. The aim of this study was to characterize the physicochemical and functional properties of modified cassava (Manihot esculenta) starch to explore their potential as an ingredient in food applications. The current study explored the effect of hydrothermal modification, HTM (30% moisture level) andacid modification, AM with hydrochloric acid on the extracted starch from two newly developed cassava variety, TME (Tropical Manihot Esculenta) 419 and TMS (Tropical Manihot Species) 0581 Amylose content and swelling power reduced significantly with AMwhereas HTM showed negligible effect. Solubility increased significantly with AM whereas HTM showed negligible effect. Both HTM and AM caused increase in gelatinization temperature with a mean value of 82.17 and 79.78 J compared to 75.83 in native starch. Transmittance decreased from day zero to fourth day for native TME starch and modified starches, but increased gradually for native TMS 0581 within the same period. Pasting profile was largely affected by AM with a significant reduction in peak viscosity whereas HTM increased the peak viscosity. The results from this study show that modification of native cassava starch produced specific characteristics that make them applicable for specific industrial applications in food preparation due to undesirable characteristics of native starch upon cooking.