Inhibition Activity of α-amylase by Crude Acidic Water Extract from Fresh Purple Sweet Potato (Ipomoea batatas L.) and its Modified Flours

Abstract

Background and Objective: Crude acidic water extracts contains phenolic compounds including anthocyanin, a very important constituent in purple sweet potato. The aim of this study was to analyzed the in vitro inhibition of -amylase activity in purple sweet potato. Materials and Method: Four treatments; fresh purple sweet potato, original purple sweet potato flour, partially gelatinized purple sweet potato flour and resistant starch-rich purple sweet potato flour were set up in a Complete Randomized Block Design (CBRD) replicated 4 times. Analysis of Variance (ANOVA) and Duncan Multiple Range Test (DMRT) were used to examine the effect of the treatments as well as the difference among treatments. Results: The results showed that crude extract of purple sweet potato and modified purple sweet potato flours significantly affected the inhibition of -amylase enzyme activity. The inhibition activity by resistant starch rich-purple sweet potato flour (TP) was 41.98%, partially gelatinized purple sweet potato flour (TG) was 32.59%, original purple sweet potato flour (TU) was 30.72% and fresh purple sweet potato (US) was 23.13%. Conclusion: The results proved that crude water extract from purple sweet potato and its original flour as well as modified flours had significant role in inhibiting -amylase enzyme activity.