Biogenic amine formation and bacterial contribution in fish, squid and shellfish

Forty-one species of fish, squid and shellfish were analyzed for biogenic amine (BA) contents. Most of the fish samples showed lower BA contents, whereas some samples showed higher contents than the allowable levels. Shellfish and squid samples had negligible BA levels. Four fish species containing high BA levels were analyzed for changes in histamine contents during storage. In the most samples, the histamine contents remarkably increased up to 36.6–2123.9 mg/kg after 24 h of storage at 25 °C, while the contents began to gradually increase after 2–3 days of storage at 4–10 °C. The dominant microbial group was enterobacteria throughout the storage period. Meanwhile, out of total 119 strains isolated from different fish species showing high BA levels, 23 strains identified as Enterobacter aerogenes produced large amounts of histamine, putrescine and cadaverine, and 33 strains identified as two different Enterobacter spp. produced less histamine but large amounts of putrescine and cadaverine.