Assessment of the hydrolytic performance of locally sourced crude amylases on root (cassava & potato) and cereal (maize) starches for syrup production

Abstract

Starches from cassava, potato and maize were hydrolysed by locally sourced crude amylases to assess and compare the performance of the enzymes in converting root and cereal starches to glucose syrup. Standard amylases (Sigma USA) served as the reference enzymes. Selected physical and sensory characteristics of the syrups produced were evaluated simultaneously with the syrups produced by the standard amylases. The crude amylases showed higher (P < 0.05) activity on maize starch than on cassava and potato starches. The hydrolytic performance of the crude
amylases increased with increase in substrate concentration up to a maximum substrate concentration of 10%. The crude alpha amylase exhibited a dextrinization time of 2.5h, 2.75h and 3.0h for maize, cassava and potato starches and produced 13%, 12% and 11.8% glucose respectively. The crude gluco-amylase had maximum saccharification
time of 72h for cassava and potato starches, 84h for maize and produced 24.37%, 21.8% and 21% glucose respectively. The crude amylases produced syrups in the type II category with Dextrose Equivalent (DE) of 47 and 50 from potato and cassava starches respectively, while syrup from maize starch fall within type III category with DE of 61. Potato starch syrup exhibited higher (P < 0.05) apparent viscosity and low (P < 0.05) mean score for colour and taste than cassava and maize syrups.