Appraising the Shelf Life of Farmed Cobia, Rachycentron canadum, by Application of a Quality Index Method

Freshness is the main concern of seafood quality, and the principal method to evaluate seafood freshness is sensory evaluation. The aim of this work was to study the quality changes of cobia, Rachycentron canadum, under ice storage through sensory and physical analysis as well as bacterial counting of specific spoilage organisms (SSOs). In particular, the utilization of a quality index method (QIM) scheme was proposed. Samples stored for 0-30 d were analyzed with the QIM. Ten panelists observed and registered the changes occurring in the fish starting on day zero and ending when the fish were spoiled. After developing the scheme, 11 sensory attributes were described in 23 points, which detailed the appearance of skin, eyes, abdomen, gills, and flesh deterioration. The volatile nitrogen compound measurements and microbiological data of the SSOs determined a shelf-life of 19 d for the samples. Sensory analysis showed a rejection point at 15.67 d of ice storage. The natural degradation of myofibrillar proteins and collagen was observed during ice storage. In conclusion, a shelf-life of 15 d was defined for raw cobia stored on ice.