A. GUNASINGH, A. ANTONIRAJ, V. HARIKARAN AND M. AMARNATH
Abstract
In this study an attempt has been made to assess the production of TMA-N in the Sciaenid fishes Johnius belangerii and Nibea maculata during cold storage. The impact of storing the fish with gut and after degutting on the production of TMA-N were studied to evaluate the effectiveness of TMA-N as an index for estimating the freshness of fish. The acceptability of the fishes sold in the local market was investigated in relation to the level of TMA-N in the fishes collected from the landing centre. Fishes collected from the landing centre were grouped as Gutted and Without Gut and stored in refrigeration at -4º C. The amount of TMA-N produced in the stored fish in increasing days of storage was determined bio-chemically. The increase of TMA-N was proportionately less in the early hours of storage and significantly increased in the final hours of storage during this study. The TMA-N content of fish stored after degutting was lower than the fish stored with gut. Significant proportion of the market samples had TMA-N content above the standard maximum acceptable limit. The present study documents the effectiveness of Trimethylamine-nitrogen in the estimation of the freshness of fish. This study further indicates that the current methods of fish harvesting, transporting, storage and retailing lack sufficient refrigeration.