Effects of fasting on the meat quality and fat deposition of commercial-size farmed gilthead sea bream (Sparus aurata, L.) fed different dietary regimes

Abstract

The aim of this study was to investigate the effects of fasting on certain quality parameters of commercial size gilthead sea bream (Sparus aurata) with different dietary history. Three dietary groups (× two replicates) were distributed into six sea cages and fed ad libitum by demand feeders for 4 months with feeds containing different protein–fat percentages (38 : 20, 45 : 15, 51 : 10). The fish were submitted to a subsequent fasting for 3 weeks. They all showed similar mobilization patterns with an initial hepatosomatic index reduction (indicating liver fat mobilization), followed by muscle fat reduction (from >90 g kg−1 to around 75 g kg−1) and a subsequent fat deposit reduction. The 3-week fasting generally improved the quality of fish without any body weight or filleting yield losses, thus indicating its possible use for end product improvement. However, another important observation was a white discoloration of the fish skin, which occurred during fasting.