Changes in ph and microbial flora of kusaya gravy during fish immersion
Nippon Suisan Gakkaishi 46(9): 1143-1146
ISSN/ISBN: 0021-5392 Accession: 004910302
Concerning the good preservability of kusaya, 2 different hypotheses were proposed. One was based on the presence of the antimicrobial substance produced by Corynebacterium kusaya and the other was based on the high-pH value of kusaya gravy controlled by some special microorganisms. In this report, to discuss these hypotheses, pH values and microbial flora of kusaya gravy were examined. The results did not provide any evidences supporting the latter hypothesis. The pH values of kusaya gravy were examined on 24 samples obtained from manufacturers of various places. Among them, 21 samples which had been successively used showed normal pH values of 6.73-7.55 and high pH values of 8.12-8.90 were recorded on 3 uncommon samples which were not used for a long time. Changes in pH and microbial flora of kusaya gravy during fish-immersion were examined at kusaya manufacturing factory in Niijima Island [Japan]. The pH during fish-immersion ranging from 6.86-7.05 did not significantly change. The dominant microflora throughout the immersion period were Corynebacterium which showed antimicrobial activity.