Abstract
In Mie prefecture, “Ayu -Zushi” has been handed down in the Miya (Ise-shi) and the Kitayama (Kiwa-cyo) River basin. For the preparation of Ayu-Zushi, salted sweetfish and cool cooked rice are combined and stuffed tightly in a wooden pail in winter. A weight is placed on the top of the wooden pail for 30-40 days at room temperature for fermentation. The contents of moisture, salt, calcium and organic acids, and pH in Ayu-Zushi prepared at Okura-cho, Ise-shi were measured. The following results were obtained.
1) The pH of Sushi-fish (pickled sweetfish) after 38 days' and 65 days' maturation was 5.10 and 4.10, respectively.
2) The salt concentration of salted sweetfish decreased from 23.2% to 8.7% after rinsing with cold water five times and 2.1% during maturation.
3) The calcium content in salted sweetfish bone was decreased from 55.5 mg/g to 25.0 mg/g after 38 days' maturation and finally reached 16.8 mg/g after 65 days. The calcium content of fish's head also decreased remarkably during maturation.
4) The content of organic acids in pickled sweetfish was lactic acid, acetic acid and succinic acid in order of the amount. These acids increased during the maturation of Ayu-Zushi. The content of lactic acid in pickled fish increased by about 26 times after 65 days' maturation. The content of organic acids in sushi-fish was more than that in sushi-rice.
5) The fermentation of pickled Ayu-Zushi proceeded quicker in the upper part of the sushi-pail than in the middle part.
