Decolorization method of sake using activated carbon fibers (ACF) made of polyacrylonitrile was studied. For decolorization and prevention of coloring of sake, ACF having larger surface area and more pore volume was suited. The flow rate of sake at ACF treatment did not affect decolorization of it, but affected a litt prevention of coloring by heat and sun-light, lower flow rate gave higher prevention of them. Between the color concentration of sake treated before and after with ACF, the following proportional relationship was observed; Y=0.464 X-0.006 (r=0.999, n=4, Y: OD430 of sake treated with ACF, X: OD430 of sake before ACF treatment). The composition of colorants with various molecular weights remained after treatment with ACF were as follows; below 5, 000: 48.4%, above 30, 000: 35.5%, and between 10, 000 and 30, 000: 16. 1%, respectively. Used ACF was easily regenerated by high pressure steam treatment (121°C, 20 min). By treatment of sake with ACF, i-AmOAc, and CapOEt decreased in addition to optical density at 430 nm.
Effect of γ-irradiation on components of traditional shochu was investigated. I. Ethylacetate and acetaldehyde in shochu increased significantly under 0.5-3.0 Mrad irradiation conditions. 2. OD27510 decreased remarkably and ethylesters of higher fatty acids decreased gradually by increasing in γ-irradiation. 3. It was recognized that a new type shochu was made by 0.5-1.0 Mrad irradiation with respect to the flavor and taste.