Abstract
Amazake was prepared using yellow-koji (Aspergillus oryzae) or white-koji (Aspergillus kawachii). In both cases, when rice-koji and water were mixed in a ratio of 1: 2, saccharification was completed in 6h and reducing sugar was formed. Changes in antioxidant activity were investigated for each amazake saccharification process. In both amazake preparations, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity increased for the first 2h of the saccharification period, and then gradually decreased. The lipid peroxidation inhibitory activity with β-carotene, however, did not change with saccharification time in either amazake preparation, and the antioxidant activity was roughly constant during saccharification. Next, both types of amazake were prepared by saccharifying for 6h at 55°C , with the respective rice-koji obtained with different koji production times (42, 48 and 54h). Antioxidant activity was then compared. It was found for both types of rice-koji that longer koji production time yields amazake with higher DPPH radical-scavenging activity and lipid peroxidation inhibitory activity.
