Studies on Cooking of Sweet Potato (Part 1)

Changes in Sugar Content and β-Amylase Activity During Cooking

Abstract

Sweet potatoes were cooked by roasting or by an electronic range. The gelatinization degree, β-amylase activity and content of reducing sugar in the baked sweet potato were determined.It was observed that content of sugar in the baked sweet potato was dependent on the degree of gelatinization and residual β-amylase activity in the baked sample. The cooking of sweet potato by roasting gave very high conversion of starch into maltose, as a result that sweet potato was slowly heated and the gelatinized starch followed by digestion with β-amylase. While, the cooking of sweet potato by the electronic range gave low conversion of starch into maltose though starch had been completely gelatinized, as a result that the heating time of sweet potato was very short and the β-amylase activity was rapidly lost.
Thus, it was confirmed that slow heating of sweet potato might give very high conversion of starch into maltose.