[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Components of sake made on a small scale often differ from those in sake brewed on a large scale, such as an industrial scale. In order to approximate the quality between small scale and large scale brewing, we studied the influence of the shape and/or capacity of vessels on components in moromi mash in a small scale, such as 100g-400g of the total rice. Results showed that, the larger the volume or the height of the space in vessels as well as the surface area of moromi mash were, the lower the concentration of malic acid and lactic acid, though, the higher were those of the succinic acid and acetic acid. The surface area or the height of moromi mash especially strongly affected concentrations of organic acids in sake in comparison with the volume or the height of the space. It is presumed that the differences in the concentrations of malic and succinic acid in moromi might be caused by an increase in the activity of enzymes in the TCA cycle in yeast cells, such as succinic dehydrogenase and fumarase.

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Methods which can produce highly concentrated γ-lactones in shochu mash by lactic acid bacteria (LAB) in collaboration with shochu yeast were studied. Three strains (26-a, 26-d and 41-d) of LAB having a high hydration ability of unsaturated fatty acids were selected from 48 "doburoku" in Japan. Two strains (26-a and 26-d) were identified with Lactobacillus brevis by their homogeny of 16SrDNA, while the other (41-d) was not identified.
In shochu brewing, unpolished rice was preferable in the supply of unsaturated fatty acids to polished rice such as koji (polishing rate 90% of rice) as raw materials. Furthermore, for β-oxidation and esterification of hydrated fatty acid, shochu yeast (SH4 or AW101) was superior to the sake yeast (K701). When LAB was added to the shochu mash, the first day of the secondary addition was preferable. Regarding the number of additional cell bodies of LAB, 1x10⁶ cfu/ml was preferable to 1x10⁵cfu/ml and 1x10⁴cfu/ml. As the result of brewing rice shochu under these conditions, γ-dodecalactone (0.16-0.35ppm) and γ-nonalactone (0.07-0.15ppm) were produced by three strains of LAB in collaboration with two shochu yeast respectively, and γ-decalactone (0.09-0.12ppm) was produced only by LAB (26-d) in collaboration with each shochu yeast.
Results of sensory tests showed that the flavor of the shochu brewed using LAB was evaluated more highly than the control (LAB was not used). For taste and total evaluation, shochu brewed using LAB of 26-d and of 41-d was judged considerably better than the control.

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