Effect of germination time on alpha-amylase production and viscosity of maize porridge

Maize grain was steeped, germinated (0 to 7 days), dried and milled. Porridge (15% dry matter) was made by adding 1:5, 1:2 or 1:1 germinated flour to ungerminated flour. A smooth batter was made prior to heating in a boiling water bath for 1 h. A second batch was left for a respite period of 1 h at 40 degreesC, before boiling. The viscosity was measured after cooling. Correlation was found between germination time, alpha-amylase content and porridge viscosity. Increasing germination time led to increased production of alpha-amylase, and corresponded to reduced viscosity. Germination longer than 2 days caused a significant reduction in the viscosity (P < 0.05). It was not possible to state any significant differences in viscosity between porridge produced with or without a respite period. However, porridge produced by including a respite period contained a significant higher amount of glucose and maltose, compared with porridge made without this processing step (P < 0.05). (C) 2002 Elsevier Science Ltd. All rights reserved.