A pungent compound produced in the meat of frozen yellowfin tuna and marlin.

Abstract

Abnormal meat with a pungent taste was detected in yellowfin tuna and white and black marlins, and food poisoning occurred by ingestion of these meats. In this study the pungent compound was identified and the cause of its production was investigated. In the abnormal meat, pH values were higher than 6.50 and histamine content was 308 to 543mg/100g. which is much higher than the amount which can cause food poisoning. The taste of the abnormal meat was just the same as that of histamine, which is known to be pungent. So the pungent compound in the abonormal meat was concluded to be none other than histamine. The values of volatile basic nitrogen and the viable counts of bacteria were low in the abnormal meat. Therefore, the abnormal meat was judged to be as fresh as the normal one. The viable counts of psychrophilic and mesophilic histamine-forming bacteria were also too low to produce a large amount of histamine. The activity of histidine decarboxylase was found to be higher in the abnormal meat than in the normal one. It is concluded that not histamine-forming bacteria but the high activity of histidine decarboxylase in the abnormal meat was responsible for the accumulation of histamine.