[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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We studied the effects of sake making processes (rice polishing, washing, steeping, steaming) and the activated carbon treatment of sake on cadmium (Cd) content. In the polishing and washing process, Cd content in rice tended to fall slightly, and it hardly changed in the other processes. In a small scale sake brewing test using distilled water and 300g polished rice, Cd content in the supernatant during moromi mash was almost constant at a low value. Also about 90 percent of rice originating Cd shifted to the sake cake. The same results as from the small brewing test were obtained during sake brewing using tap water and 100 kg polished rice. The sake with Cd added (about 50 μg/kg) was treated with 10-1000 mg/kg activated carbon for 1 week, but no effect of a notable adsorption of Cd was seen.

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The effects of brewing on the levels of Methamidophos, Acetamiprid, and Aflatoxin B1 in sake samples were investigated. In the fermentation process, the concentration of the pesticides and Aflatoxin B1 decreased with time when we added these substances at 10 or 20 ppb. These values differed depending on the kind of pesticide. When we compared the residual rate in the liquid and the solid part at 20 days after a 3 rd adding, a greater amount of Metamidophos remained in the liquid part. In the case of Aflatoxin B1, the solid part contained more. On the other hand, Acetamiprid remained at the same rate in both the liquid and solid part. Activated carbon (100 mg/L or 300 mg/L) absorbed more than 50% Acetamiprid and Aflatoxin B1 for 30 minutes. Methamidophos, however, was not influenced by the activated carbon process. Ninety percent or more of the pesticides and Aflatoxin B1 remained after heating (75°C). In other words, the pesticides and Aflatoxin B1 could not be effectively degraded or eliminated in the heating processes. The storing time did not influence the concentration of Methamidophos and Acetamiprid. After 5 months, Aflatoxin B1 in the solid part was degraded, but it did not show a significant difference.

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