Feasibility Study of Thai Rice for Mirin Making

Abstract

The objectives of this research were to study the process of mirin making by using Thai rice cultivars, and to investigate a suitable strain of Aspergillus oryzae. Another purpose of this study was to create value-added Thai rice product to reduce mirin importation from foreign country. The result showed that mirin produced by Aspergillus oryzae strain No.3 isolated from commercial spore produced enzyme α-amylase at the highest level. Meanwhile, Chai Nart, a non-glutinous rice cultivar was the most suitable for preparation of koji because its unaggregation characteristics which are good for enzyme production (226.84 units/mL of α-amylase and 46.70 units/mL of glucoamylase). Study on the suitable ratio of solid (koji and steam glutinous rice): liquid (35% (w/w) of ethyl alcohol) was found that mirin formula B at the ratio of solid: liquid equal to 65 : 35 was the most appropriate because it gave the pale yellow color, residual alcohol concentration 12.63% (v/v) and reducing sugar at 38.76% (w/v) which have a good flavor similar to commercial mirin in the market.