Study on formula determination and saccharifying condition for fermentation of taro Shochu

• Main Authors: Wen-Ta Li, 李文達
• Other Authors: 陳錦樹
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/67076280424814498725

碩士 === 國立中興大學 === 食品暨應用生物科技學系 === 95 === Abstract Shochu is a traditional spirit in Japan. After mixing moto (created by mixing rice-koji with cooked rice, yeast and water) with the main ingredients, alcohol fermentation is performed for 10 to15 days. Then the fermented mash is distilled to produce Shochu.The followings were accomplished in this study:1)Effects of saccharifying activities of koji molds（K1,K2 and K3）on fermentation; 2)Determination of formula of rice-koji, taro and water to produce taro shochu. Results showed that K1 has the highest amylase activity which is 917u/g, while for K2 and K3, which have similar amylase activities, are 297 u/g and 281 u/g,respectively,Both K3 and K2 have higher acid protease activity, 8.7 u/g and 8.3 u/g,respectively, compared to K1, 4.3 u/g the titratable acidity(as lactic acid)for the K2 was the highest, 54.9 mg/g, and K1 have the lowest, 5.41 mg/g. After testing different formula, the highest alcohol production yield of 88.8% is obtained when the proportion of rice to taro is 1:7, and the aroma components ethyl acetate is detected.The highest alcohol production yield is 95.5% when the ratio of rice-koji to water is 1:12.5. Amounts of alcohol, methanol and fusel oils, 2-phenylalcohol, ethyl acetate and ethyl lactate in fermented mash (moromi) were analyzed after 14-day fermentation. K2 has the highest alcohol content 13.5%, and K1 has the lowest content 11%. The methanol contents in moromi of both K2 and K3 are higher, 178ppm and 158ppm,respectively. K2 and K3 have higher propanol, iso-butanol and iso-amyl alcohol contents.As for the amount of 2-phenyl alcohol,they are same for K1, K2, and K3. The aroma component ethyl acetate is not detected in K1, but 59ppm for K2 and 98ppm for K3 are found. K1 has the highest content of ethyl lactate 144ppm, while those for K2 and K3 are only half of it compared with K1. Moromi is distilled to 25% alcohol content. On the basis of 2 liter of moromi,the volume of distillates and alcohol content obtained after distillation are 510ml 55%（K1）, 580ml 63%（K2）, and 540ml 60%（K3）,respectively. As for the results of hedonic sensory evaluation, Shochu made by K2 showed the best in aroma and taste scores. Therefore, on the basis of the efficiency and economic consideration, K2 is the most suitable rice-koji to be used to produce taro Shochu.The optimum formula for large scale of production of shochu: ratio of rice:taro is 1:7 rice-koji:water is 1:12.5. Key word：rice-koji ; moto; shochu ; fermented mash or moromi ; spirit