ABSTRACT
Crude maize amylase was extracted from twenty (20) cultivars of maize grains obtained from International Institute of Tropical Agriculture (IITA), Ibadan. Cassava starch was extracted from eight (8) varieties of hydrid cassava tubers from IITA, Ibadan. Maize amylase activity was determined by the Dinitrosalicyclic acid (DNS) method using 1% pure soluble corn starch as substrate. The effects of pH, Ca2+ ion on enzyme activity with highest activity was used to hydrolyze the cassava starch from the eight varieties of cassava. Amylase activity was found in
ungerminated and germinating maize. The highest activity was detected on the third day of germination in all maize varieties. The pH profile produced three peaks at pH 5.5, 7.5 and 9.5 suggesting three isoenzyme forms suspected to be -amylase, --amylase and limit dextrinase, Ca2+ (0.05M) activated amylase activity two fold, while Ca2+ (0.1M) inhibited it two-fold. The highest amylase activity was determined with maize variety coded Y-Syn-VAR-IF2. All eight varieties of cassava starch were hydrolyzed by maize amylase. The highest amount of reducing sugar (glucose) was obtained from the cassava variety coded TME 419. The rate of hydrolysis of cassava starch was as pure soluble corn starch.
