Abstract
Fish sauces made from Japanese common squid internal organs (IKA-ISHIRU) or whole sardines (IWASHI-ISHIRU), have been produced in Noto peninsula of Ishikawa prefecture. Seven kinds of polyamines i.e. histamine(Him), tyramine(Tym), putrescine(Put), cadaverine(Cad), agmatine(Agm), tryptamine(Tpm) and spermidine(Spd) in commercial ISHIRU were analyzed, and changes in the composition of these polyamines during the processing of ISHIRU were also investigated. The major polyamines of both commercial ISHIRU were Him, Spd, Tym and Put, and IWASHI-ISHIRU contained larger amount of Him than IKA-ISHIRU. When the both ISHIRU are experimentally fermented, the contents of Cad, Agm and Spd decreased in IKA-ISHIRU during the fermentation and reached the steady states over about 8 month. Other polyamines of IKA-ISHIRU showed the same levels during the fermentation. In the case of IWASHI-ISHIRU, although histamine increased slightly during the fermentation until 6 month , other polyamines kept the same levels during the fermentation. From these results, it is presumed that the contents of polyamines in ISHIRU were related with a freshness of raw materials and ingredients, and that the microorganisms like histamine-producing bacteria were hardly concerned in the formation of polyamines in ISHIRU.
