Quality outline of European sea bass (Dicentrarchus labrax) reared in Italy: shelf life, edible yield, nutritional and dietetic traits

The final product quality of European sea bass was outlined through some re sults on (1) quality traits in a large range of body size (80-1580 g weight ) and (2) changes in sensorial and objective quality parameters during shel f life, as influenced by the rearing system, storage and stress. More than 500 European sea bass of commercial size were used in several trials. All f ish were subjected to linear and weight measurements. In most trials, sea b ass were stored at 4 or 1 degreesC with ice cover and evaluated every 24 h after death until spoilage for the EU freshness classes and for a large num ber of physical and chemical quality traits (rigor index, dielectric proper -ties, muscle and eye liquor pH, water-holding capacity (WHC), water, prote in, ash, total, neutral and polar lipids, cholesterol, fatty acids, malonal dehyde, adenine nucleotides and biogenic amines). Fillets showed on the ave rage isometric growth, but the dorsal muscle grew faster and the ventral on e slower than the body weight. A moderate corpulence increase in fish shape during growth emerged. The size range from 500 to 940 g-when incidences of fillets and dorsal muscle were higher than 48% and 31% and that of viscera was lower than 10%-can be suggested for having sea bass with the better ed ible portion yield. Protein and ash contents of muscle remained constant wi th body weight increase, while moisture and cholesterol content decreased; total lipid moderately increased along with the triglyceride incidence. On the whole, the muscular fatty acid pattern determined good indexes of ather ogenicity (IA) and mostly of thrombogenicity (IT). Sea bass stored at 4 or 1 degreesC with ice cover had a 6- and 10-day shelf life, respectively. In the first 2 and 3 days, respectively, sea bass were Extra (always with 100% rigor index) and had Fish Tester values decreasing to 64 or 73, respective ly, and negligible levels of malonaldehyde (MDA) and biogenic amines. In th e following 2 and 3 days, respectively, sea bass became A fish (good qualit y), with decrease of rigor index (IR) and Fish Tester (FT) and slight incre ase in malonaldehyde and putrescine contents. In the following 2 and 4 days , respectively, sea bass became B fish (bad quality), with further decrease of rigor index and Fish Tester and moderate increase of malonaldehyde and putrescine. Thereafter, fish were unfit for human consumption. No differenc e in quality parameter of fish reared in aerated (4.3 ppm O-2) or hyperoxic (9.3 ppm) conditions was found. Stress shortened the pre- and post-rigor p hase and shelf life. (C) 2001 Elsevier Science B.V. All rights reserved.