Abstract
In the preparation of ayu-narezushi, a traditional food in Toyama, Japan, rice-koji is added to the other ingredients and then subjected to a 40-day ripening period. In this study, viable cell counts, pH, organic acids and free amino acids were periodically analysed during ripening. After 8 days of ripening, the number of lactic acid bacteria reached approximately 108cfu/g, and then onward, numbers were maintained in the same order of magnitude. The pH was drastically reduced to 4.8 in the first 8 days of ripening, and was thereafter maintained between 4.6 and 4. Lactate content was drastically increased within the first 22 days. Furthermore, total free amino acids were increased by 22 days of ripening ; thereafter increasing moderately. These results showed that lactic acid fermentation developed rapidly in the ripening of ayu-narezushi made with rice-koji.
