Abstract:
Chemical composition of polished rice variety, Loy, Goh-koh6 and Kak-dok-mali105, at leve 0 (rice brown, 100% polishing ratio), 1 (86-85% polishing ratio) and 2 (82-82% polishing ratio) were analyzed. The fat contents of the polished rice at level 0 were 2.39%, 2.41% and 2.55% respectively, level 1 were 0.49% 0.53% and 0.44% respectively and level 2 were 0.25% 0.24% and 0.2% respectively. The protein contents of the polished rice at level 0 were 6.77% 6.6% and 6.46% respectively, level 1 were 6.18% 5.64% and 5.67% respectively and level 2 were 6.19% 5.67% and 5.64% respectively. The ash contents of the polished rice at level 0 were 1.01%0.78% and 1.06% respectively, level 1 were 0.33% 0.27% and 0.35% respectively and level 2 were 0.32% 0.28% and 0.29% respectively. The amylose contents in Loy variety with the polished rice at level 0, 1 and 2 were 28.79, 33.78 and 34.76 respectively, Goh-koh6 with the polished rice t level 0, 1 and 2 were 5.25, 7.54 and 7.36 respectively and Kaw-dok-mali105 with the polished rice at level 0, 1 and 2 were 18.32, 19.23 and 20.34 respectively. For rice wine preparation, the rice was steamed and mixed with mould starter (Amylomyces rouxii TISTR3128) incubated 5 days at room temperature, yeast starter (Saccharomyces cerevisiae TISTR 5049) was added and fermented for 14 days. Chemical composition of rice wine was analyzed every 2 days. The polished rice at level 0 was the best substrate for alcohol production and the reducing sugar was used up in 2 day, while other 2 levels of polishing ratio, the rate of alcohol production was lower than the polished rice at level 0 and reducing sugar decreased during fermentation. Alcohol cohcentration of rice wines were 9.2-12.6%. The rice wines were filtered and analyzed for ester compounds and fusel oils. Sensory evaluation was also performed. It was found that the level of ester compounds and fusel oils were not correlated with the polishing ratio. Rice wine made from polished rice from goh-koh6 at level 1 and 2 had over all acceptability and odor more than Loy polished rice at level 0, 1 and 2, Goh-koh6 polished rice at level 0 and Kaw-dok-mali105 in the polished rice at level 0, 1 and 2.