Influence of size reduction of waxy rice kernel on Sato production and its volatile compounds

Abstract

To reduce the production cost of Sato, this study investigated the influence of using reduced sizewaxy rice kernels on Sato production and quality. Reduced sized waxy rice was made to 1.4-1.7 mm, 1.7-2.0 mm, 2.0-2.3 mm, and full kernels (control). Aspergillus niger TISTR 3257 was used to make koji at 30 o C for 7 days. Saccharomeces cerevisiae SC90 was used during alcoholic fermentation at 30 o C for 8 days. The highest crude amylase activity (0.341unit) was observed in the koji made from 2.0-2.3 mm waxy rice. The growth pattern of yeast and alcoholic content (~10% v/v) did not show any difference among samples (p>0.05). The Sato made from waxy rice size 2.0-2.3 mm contained significantly higher concentration of ethyl butyrate, ethyl decanoate, diethyl succinate, phenyl acetate and 2-methyl-1-propanol, 3-methyl-1-butanol, phenethyl alcohol compared with those of the control sample (p < 0.05). This clearly shows that the reduction in size of waxy rice kernel to 2.0-2.3 mm influences the production of volatile compounds.