抄録
Since 1961, much attention has been paid on the new types of deterioration of fish sausage among Japanese fisheries industries. The deterioration is characterized by the formation of spots or speckles on the surface of fish sausage, or by the formation of gas in fish sau-sage.
These organisms causative of deterioration were isolated by YOKOZEKI1) from deteriorated fish sausages, and the spot forming organisms have been identified with B. coagulans; speckle-formers with B. subtilis, B. firmus and B. circulans; and gas-formers with B. firmus, B. sphaericus and B. circulans.
The use of certain amount of nitrofurazone (NFS), nitrofuryl-acrylic amide (NFA), and/or sorbic acid is legally permitted in Japan for keeping the quality of fish sausage and other fish paste products such as “kamaboko”.
In the present paper, minimal concentrations of aforementioned food preservatives for the growth inhibition of the causative organisms which were given by courtesy of YOKOZEKI and the stock strains of same species of causative organisms were determined.
Results obtained may be summarized as follows:
1. All deteriorating organisms of fish sausage showed high resistance to the preservati-ves, especially higher to NFS. To the contrary, stock strains were fairly susceptible to the preservatives except sorbic acid (Tables 1 and 4). No appreciable growth inhibitory action was observed by sorbic acid for these organisms including stock strains at the maximum permissible concentration of 0.2% at pH 6-7, the ordinary range of pH of fish sausage (Tables 2 and 3).
2. Distribution patterns of viable counts of several test organisms exposed to various con-centrations of NFS (Fig. 1) indicate that 2 strains of the causative organisms (B. coagulans) have comparatively uniform resistance to the drug, more remarkable uniformity in resistance was noted in the 2 species belonging to Pseudomonas, whereas 2 species of susceptible bacilli (B. subtillis and B. coagulans) were rather uneven.
