Suitability of volatile amines as freshness indexes for iced Mediterranean hake

Batches of gutted Mediterranean hake (Merluccius merluccius var. Mediterraneus) were stored, in different seasons of the year, for up to 20 d in ice. Changes in trimethylamine (TMA-N), total volatile bases (TVB-N), P-ratio and trimethylamine oxide (TMAO) were measured; sensory evaluation of raw and cooked hake samples was also carried out. Similar profiles were observed between the different trials for all the parameters studied. TVB-N was i not correlated with the time of ice storage, and proved to be better as a spoilage index than a freshness one. In contrast, TMA-N appears to be a good index of hake quality, and the value of 5 mg/100g of fish seems an appropriate limit of acceptability. P-ratio was a poorer index of freshness than was TMA-N.