The influence of starvation time prior to slaughter on the quality of commercial-sized gilthead seabream (Sparus aurata) during ice storage

Farmed commercial-sized gilthead seabream were subjected to different periods of starvation (24, 48 and 72 h) before being slaughtered in order to study the effect this had on post mortem quality and shelf-life. Once slaughtered (by immersion in a 1:3 ice water mixture), the animals were stored on ice at 4 °C for 0, 7, 14, and 21 days. In this manner, 12 groups were formed, each subjected to a different combination of starvation periods and storage times. At each point during the sampling, physical–chemical (pH, TBA, TVBN, color and texture), microbiological and sensory analyses were performed to determine the spoilage that had occurred in the fish. Higher pH values were found in animals that were starved for 24 or 48 h, than in those starved for 72 h. These values were the highest on days 14 and 21. Variations in TBA were not significant in any of the treatments. The TVBN increased with the number of days stored on ice. Color variations were most significant on the dorsal parts of the fish, with a discoloration occurring as the days went by in ice storage. The texture analysis revealed a certain softening of the flesh with time spent in storage, as well as a reduction in cohesiveness as the starvation period was prolonged. The microbiological analysis (total aerobic and Pseudomonas counts) and the quality index showed very significantly the deterioration in gilthead seabream as the on-ice storage time and the starvation time increased. The shelf-life was estimated to be 16 days for seabream starved for 24 h, 15 days for those starved for 48 h and 14 days for those starved for 72 h.