Abstract

Native starches isolated from cassava cultivar (TME 305) and red cocoyam were chemically modified by phosphorylation using sodium tripolyphosphate (STPP). Proximate analysis, some functional properties, pasting properties and FTIR of the native and modified starches were determined. The proximate analyses revealed that the fats and crude protein contents reduced after phosphorylation with the red cocoyam starch showing a greater reduction while the moisture content, water and oil absorption capacity, swelling power and solubility increased after phosphorylation with the red cocoyam starch showing the greater increase when compared to the cassava starch. Pasting temperature, peak viscosity, final viscosity, breakdown and setback viscosity increases following chemical modification while the trough viscosity decreases after phosphorylation. Phosphorylation increased the setback values in both starches indicating that chemical modification increased starch retrogradation. The chemical modification on the native cassava and red cocoyam starches through phosphorylation had improved the solubility, texture, adhesion and tolerance to the kind of temperature used in industrial processes.