PRODUCTION OF HISTAMINE AND TYRAMINE BY LACTIC-ACID BACTERIA ISOLATEDFROM VACUUM-PACKED SUGAR-SALTED FISH

The incidence of histamine- or tyramine-producing lactic acid bacteria was examined in several products of vacuum-packed sugar-salted fish ( salmon, halibut, mackerel). No histamine-producing isolates were obser ved, whereas the majority of tyramine-producing isolates were identifi ed as Carnobacterium spp. These organisms were shown to be important m embers of the microbial flora during storage of vacuum-packed sugar-sa lted salmon at 5 degrees C. The amount of tyramine produced was reduce d by lowering the temperature from 9 degrees C to 4 degrees C for all of five strains of carnobacteria or lactobacilli. The majority of tyra mine was produced during the exponential growth phase for Carnobacteri um piscicola N 5 and Lactobacillus viridescens N 69. The ability of th ese bacteria to produce tyramine may be used as an index of microbial quality/acceptability of stored vacuum-packed sugar-salted fish.