Effect of steeping conditions on the amylolytic development of some Nigerian improved sorghum cultivars

摘要

Nigerian improved sorghum cultivars ‘L538’, ‘YG5760’, ‘L1499’, ‘SSH1’ and ‘SSH3’ were investigated for the effect of steeping conditions on their amylolytic development. The grains were steeped using 3 steep regimes SR 1, SR 2 and SR 3 which involved steeping and re-steeping in cold distilled and de-ionized water for 36, 45 and 54 h respectively. Grains in each SR were divided into 4 portions and further steeped for 6 h using final warm steep temperatures (FWST) of 30, 35, 40 and 45°C. α-and β-Amylase as well as diastatic activity were determined at different FWST. SR and FWST were correlated with enzyme development. Steeping conditions significantly (p<0.05) affected amylolytic development of the sorghum malts. Optimum moisture content (48%) was obtained at FWST of 35°C. α-Amylase was the predominant enzyme. All enzyme activities were at a peak at FWST of 30 and 35°C and at SR 2. The highest enzyme activity was recorded by cultivar ‘YG5760’ malt-(α-amylase 272, β-Amylase 169 μg equivalent glucose). High relationship existed between α-amylase and moderate relationship between β-Amylase and SR. Similar relationship existed between enzyme development and FWST.