Changes on the contents of total volatile basic nitrogen and biogenic amines in two common species of freshwater fish, Hemiculter leucisculus and Erythroculter erythropterus, at high temperature storage

Hemiculter leucisculus and Erythroculter erythropterus are small fishes which are common freshwater species in China. They are often fed to aquatic animals, and are also food for humans. In this study, the total volatile basic nitrogen (TVBN) and nine biogenic amines (cadaverine, putrescine, histamine, tyramine, serotonin, spermidine, spermine, dopamine and octopamine) of H.leuciclus and E.erythropterus at 30℃ storage were examined in every 6h for 48h. The correlation analysis of the contents of TVBN or biogenic amines with the storage time was also evaluated for these two species. The results showed that there were differences in the contents of biogenic amines and TVBN in H.leucisculus and E.erythropterus. The TVBN contents of H.leuciclus and E.erythropterus obviously increased with the storage time increasing. The TVBN content of E.erythropterus was significantly higher than that in H. Leucisculus at all time except at 42 h (P<0.05). The TVBN contents of H. leucisculus and E.erythropterus exceeded the national edible standard of 30 mg/100 g after 12h. Therefore these two species were not suitable to eat after 12 h. The four main biogenic amines detected in these two species were cadaverine, putrescine, tyramine and histamine. The contents of these four biogenic amines increased significantly with the extension of storage time (P<0.05). The contents of cadaverine and histamine in E.erythropterus were significantly higher than those in H.leuciclus (P<0.05). The contents of TVBN, cadaverine, putrescine, histamine and tyramine were found to correlate closely (P<0.01) with the storage time in these two species, and the same situation was also found for serotonin from E.erythropterus.