Total volatile base nitrogen and its use to assess freshness in European sea bass stored in ice

During a study on shelf life, different parameters were analyzed. For this reason, one group of farm raised European sea bass (Dicentrarchus labrax) from Canary Islands (Spain) sea waters were stored in melting ice for a period of 21 days from the time of harvest. The samples were assessed for their total volatile basic nitrogen contents (TVBN) at regular intervals (0, 2, 4, 7, 10, 14, 18 and 21 days). There was practically no change in the level of TVBN during the edible storage life of the fish. After obtaining poor results in this first experiment, another group of sea bass were studied for a period up to 21 days (0, 2, 4, 7, 10, 14, 18, 21, 24 and 28) out of their shelf life time. This new set showed an increase of volatile bases after 20–22 days of storage. This experiment demonstrates unlike previous ones there exists an evolution of the volatile bases but out of its shelf life. This retarded evolution prevents the use of the TVBN limits as a test. TVBN should be considered a very unreliable indicator by freshness with European sea bass and it must not be used in its application as a reference method to refuse sea bass in markets.