Measurement of Histamine, Listeria monocytogenes, and Mercury (Hg) in Steak Tuna Product

Abstract

The export of tuna fish is an essential activity, with major destinations being the United States, China, Japan, ASEAN, and the European Union. The export of fishery products is subject to strict regulations on the levels of histamine, mercury (Hg), and the presence of Listeria monocytogenes. In this study, we aimed to determine the levels of histamine and mercury, as well as the presence of L. monocytogenes, in steak tuna products intended for export. The samples were analyzed for histamine levels using Enzyme-Linked Immunosorbent Assay (ELISA), mercury levels using Atomic Absorption Spectrophotometer (AAS), and the presence of L. monocytogenes using Real Time-PCR. Results from our study indicated that all samples with temperatures ranging from −0.2 to −0.3°C had a histamine content of less than one ppm, which meets the acceptance standard for histamine on tuna exports as stipulated by European Commission (EC) number 2073/2005. Additionally, the mercury level in all samples was less than one ppm, which also meets the acceptance standard for mercury on tuna exports as stipulated by EC number 617/2022. Furthermore, L. monocytogenes were absent in all the samples analyzed. Based on our findings, we conclude that steak tuna products are suitable for export to various countries, especially those in the European Union.