Changes in histamine and volatile amines in six commercially important species of fish of the Thoothukkudi coast of Tamil Nadu, India stored at ambient temperature

Six commercially important species of fish, i.e. mackerel (Rastrelliger kanagurta), sardine (Sardinella fimbriata), emperor bream (Lethrinus miniatus), threadfin bream (Nemipterus japonicus), trevally (Carangoides armatus) and barracuda (Sphyraena barracuda) of the Thoothukkudi coast of Tamil Nadu, India, were examined for changes in histamine and volatile amines (TVB-N and TMA-N) under ambient temperature storage (32±2 °C). Fish were organoleptically acceptable up to 15 h of storage, except emperor bream that spoiled after 12 h of storage. Histamine and volatile amines increased progressively on storage, but the rate of change varied with the species of fish. The TVB-N content of barracuda and emperor bream exceeded the acceptable limit of 35 mg/100 g after 15 h of storage while, in other fishes, their formation was slow. However, the TMA-N contents of all the fishes were above 10 mg/100 g after 15 h of storage. The TMA-N content of fish was found to correlate more closely with the sensory changes than the TVB-N content. With regard to the histamine toxicity, the histamine content was above the USFDA maximum allowable limit of 50 ppm in mackerel after 12 h, and, in sardine and trevally, after 15 h of storage. The histamine content did not show any correlation with the sensory changes or with the content of volatile amines. In trevally, it was noted that the histamine formation was very high and similar to that of mackerel. It is therefore concluded that the mackerel, sardine and trevally could cause histamine toxicity problems before they become organoleptically unacceptable.