[in Japanese]

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 Sushiko is a fermented sushi (Narezushi) prepared in Tsugaru area, Aomori, Japan. Here, microorganisms, particularly lactic acid bacteria and yeast, which are involved in the preparation of Sushiko, were investigated. Lactiplantibacillus plantarum and Latilactobacillus sakei were isolated from Sushiko as lactic acid bacteria, and Kazachstania servazzii and Wickerhamomyces anomalus were isolated as yeast. The composition of these species varied according to the season in which they were produced. L. plantarum accounted for 92 %–95 % of bacterial flora of Sushiko produced in August. And the fungal flora of Sushiko mainly consisted of K. servazzii and W. anomalus. K. servazzii and W. anomalus accounted for 44% and 54.8% of the fungal flora, respectively. In Sushiko stored at 4°C for 1 month, the dominant species of yeast was K. servazzii, accounting for 84.1 % of the fungal flora. Overall, the microorganisms involved in preparing Sushiko vary depending on the season in which it is prepared, resulting in variations in flavor. Additionally, chilled storage changes the flavor due to the replacement of the dominant yeast.

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 Aroma is an important parameter of chocolate quality. Chocolate is a food product that can be stored for long periods of time; however, its quality deteriorates over time, resulting in poor aroma. As the ratio of liquid to solid fat and volatile components of chocolate vary according to the content of cocoa, it is expected that cocoa content will influence the changes in mouthfeel and aroma during storage. Four types of chocolate with different cocoa contents were used to determine the changes in aroma and fat parameters during storage. The quantities of aroma components decreased with storage; and the sample with the lowest cocoa content showed a steeper decline. The solid fat content was correlated with cocoa content, and the solid fat in sample with high cocoa content increased up to 14 days of storage. Moreover, the aroma content was retained in sample with high cocoa content, suggesting that the increase of solid fat content was related to suppress the release of aroma.

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