| Summary: | 碩士 === 大葉大學 === 生物產業科技學系 === 97 === In this thesis, cooked red sorghum rice, cooked wheat, cooked rice, cooked corn flake, and cooked or uncooked soy flake (or uncooked soy flour or uncooked soy bean residue) were used as main materials to made five-grain spirits using Bo-shin PY 2102 Koji as fermentation flora. During fermentation of five-grain spirits, solid fermentation was conducted for three days and then changed into liquid fermentation with or without hexanoic acid added for another four days. During fermentation, the temperature of the mash was between 26℃~35℃; the specific weight was between 0.99~1.022; the pH was between 3.6~4.5; the soluble solid content was between 5 ~12 °Brix.
The fermentation took seven days. After fermentation, the five-grain mashes were conducted to distillation to collect the first time distilled spirits that have the total alcohol content of 50 %. After distillation, the grains were conducted to the second time fermentation and then distillation to collect the second time distilled spirits that have the total alcohol content of 50 %. After distillation, the grains were conducted to the third time fermentation and then distillation to collect the third time distilled spirits that have the total alcohol content of 20 %. The third time distilled spirit was then conducted to redistillation to obtain the redistilled spirits that have the total alcohol content of 50 %. After 180 days’ storage, the spirits were panel tested and the pH, total acid content, and total ester content of the spirits were compared. The volatile compounds in the spirits of more acceptable were also analyzed and compared.
For the first time distilled spirits, the cooked soy flour without hexanoic acid added process was found to have higher yield of spirit (3198 ml/4 Kg sorghum rice). For the second time distilled spirits, the cooked soy flour without hexanoic acid added process was found to have higher yield of spirit (2183 ml/4 Kg sorghum rice). For the redistilled spirits, the uncooked soy bean residue without hexanoic acid added process was found to have higher yield of spirit (1406 ml/4 Kg sorghum rice). For the total amount of distilled spirit, the cooked soy bean residue without hexanoic acid added process was found to have higher yield of spirit (6303 ml/4 Kg sorghum rice ).
When the spirits were conducted to panel test, the first time distilled spirit of the uncooked and without hexanoic acid added process was found to be more preferred. When hexanoic acid was added during fermentation, significant amount of ethyl hexanoate was found in the relate spirit.
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