Sensory, physical, chemical and microbiological changes in aquacultured meagre (Argyrosomus regius) fillets during ice storage

Commercial-sized meagre fillets were stored on ice at 4 °C for 18 days, in order to evaluate the loss of quality and freshness that occurs over this period of time. Physicochemical (pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVBN), trimethylamine (TMA), water activity, water-holding capacity, colour, texture and fatty acid profile), sensory and microbiological analyses were carried out at 0, 4, 7, 11, 14 and 18 days of storage. As part of the sensory analysis, attributes associated with fillet appearance, odour and texture were examined. Variations in pH, TBA, TVBN and TMA were observed throughout the storage period, although only TBA displayed a significant correlation with time (r = 0.96). L∗ and b∗ values increased, and the chroma and hue values decreased, reflecting the colour changes experienced by the fillets over time. With regards to the texture profile, hardness was significantly correlated with time (−0.68). All the sensory analysis attributes exhibited significant variations and correlations close to 1.00 with storage time, which is a reflection of the fillets’ loss of freshness. The correlation coefficients between aerobic mesophilic and psychrophilic bacteria, enterobacteria and coliform counts on the one hand and storage time on the other were also very high (0.99–1.00). A regression analysis using the acceptability limit set by the ICMSF standard (1986) for total aerobic mesophilic counts (7 log cfu/g) yielded a shelf-life for meagre fillets of 9 days. The TBA, sensory and microbiological analyses displayed very strong correlations with storage time, and they may be considered suitable indicators for evaluating meagre fillet spoilage during refrigerated storage.