DETERMINATION OF DIFFERENT VOLATILE BASE COMPONENTS AS QUALITY CONTROL INDICES IN FISH BY OFFICIAL METHODS AND FLOW INJECTION ANALYSIS

Flesh concentration of Trimethylamine Oxide-Nitrogen (TMAO-N), Trimethylamine-Nitrogen (TMA-N) and Total Volatile Base Nitrogen (TVB-N) are the most studied parameters used as indices of spoilage in fish and fishery products. In the present work, the official methods to determine TVB-N, TMA-N and TMAO-N were compared with the Flow Injection Analysis (FIA) technique using three different fish species over their storage in melting ice for a period of 16 days. There was a good correlation between determinations made using official and FIA methods with no apparent significant differences. FIA thus appears to be a suitable method for TMAO-N, TMA-N and TVB-N in fish extract and the use of this system is much faster and simpler than the official methods for determination of these parameters. On the other hand, the individual concentrations of TMAO-N, TMA-N and TVB-N were not found to represent reliable indices of spoilage in fish, which had been frozen and thawed and then presented in chilled format.