Fish quality and nutritional assessment of yellowfin tuna (Thunnus albacares) during low temperature storage

Assessment of fish freshness is the most important and frequently difficult to determine. Moreover, fish spoilage generally depends on the temperature to control the bacterial and the autolytic development. This research was aimed to determine the quality of yellowfin tuna and skipjack tuna using physical, sensory, microbiology and chemical methods as well as their nutritional quality during certain time of freezing temperatures storage. Methods applied in this study were: organoleptic test with semi-trained panelist, pH, TPC and TVB determination monthly during 6 months of storage. Nutritional values were determined by the variation of their amino acid and lipid profiles. The results indicated that the pre-rigor phase was happened during storage until the 3rd month. In the 4th month of storage to the last month the fish samples were in the phase of rigor mortis. Organoleptic and pH value trends were decreased while the value of TPC and TVB were increased during 6 months freezing temperatures. In conclusion, during 6 months low temperature storage, the freshness quality of yellowfin and skipjack tuna as well as their nutritional value were decreased. Thus, there was fixed correlation between pH, TVB, TPC, organoleptic and nutritional values with fish freshness quality.