Effect of Acetic Acid and Alpha-Amylase Modifications on Some Physichochemical Properties of Xanthosoma sagittifolium (Cocoyam) Starch

Abstract

This study was aimed at evaluating the effect of acetic acid and alpha-amylase modifications on the physicochemical properties of Xanthosoma sagittifolium (cocoyam) starch. Standard procedures were employed in determining the physicochemical features of the starch. The yield of starch from cocoyam root was 22.30 %. The result showed that of the native and modified starches did not show significant difference in the moisture content, and the swelling capacity of the native and modified starches. The amylose content showed that acetic acid modified starch had significantly (p<0.05) higher amylose content (10.07±0.20 %) than the native and enzyme modified starches. The solubility of the starch was shown to be significantly (p<0.05) higher in the native cocoyam starch (3.75 g/g) than in either acetic acid or enzyme modified starch (3.30±0.02 and 3.04±0.01 g/g) respectively. The gelatinization temperature of the starches was found to be significantly (p<0.05) higher in the modified starch (82.51±0.08 and 81.15±0.05 oC) than native starch. The water absorption capacity was significantly higher in native starch (6.65±0.12) than in the modified starches (2.14±0.07 and 2.03±0.04 for acetic acid and enzyme modified starches respectively). It is therefore noteworthy that modification of cocoyam starch may present it a worthy resource material for industrial application as such popularising its utility