Accurate Estimation of Sweetpotato Amylase Activity by Flour Viscosity Analysis

Abstract

Sweetpotato flour (SPF), prepared from 44 genotypes adapted to Philippine conditions, showed wide variation in Rapid Visco-Analyzer (RVA) pasting characteristics due to its variation in composition and endogenous amylase activity. The RVA pasting parameters of peak viscosity determined in water (PV1) and that determined in 0.05 mM AgNO(3) (used as an amylase inhibitor) (PV2) were successfully used to estimate alpha-amylase activity. The correlation of the ratio (PV2-PV1)/PV1 to alpha-amylase activity was 0.96 (p < 0.01, N = 44). Swelling volume measurements were not found to be suitable for prediction of alpha-amylase activity.