Changes in enzyme activities during germination of cowpeas (Vigna unguiculata, cv. California blackeye)

Cowpeas (Vigna unguiculata, cv. California blackeye), steeped at 25°C for 20 min, were germinated at room temperature for 0, 1, 2 and 3 days. The samples were then dried at 60°C for either 2.5, 5, 7.5 or 10 h. α-Amylase, β-amylase and endo-(1,3)(1,4)-β-D-glucanase activities were determined in the cowpea samples. The results obtained showed β-amylase activity was not present in any of the experimental samples. Germination had a highly significantly positive effect on α-amylase activity (P<0.05), where activities ranged from 85.6 to 720.9 μmoles maltose/ml/min at day 0 to day 3 of germination. The effect of germination and drying time on α-amylase activity was significant (P<0.05). Compared to α-amylase activity, the activity of endo-(1,3)(1,4)-β-D-glucanase was low. Further analysis, using Duncanʹs Multiple Range Test, indicated that there was no significant difference in α-amylase activity in samples dried for 5–10 h at 60°C.