Improved quality and shelf life of farmed trout (Oncorhynchus mykiss) by whole processing in a combined ozonised flow ice refrigeration system

A combined refrigeration system consisting of ozone and flow ice was evaluated for the sacrifice, cooling and chilled storage of continental trout. The batch processed in ozonised flow ice exhibited significant ( P  < 0.05) reductions (0.97 and 1.51 log CFU cm⁻²) in skin aerobes and psychrotrophs on days 6 and 9, respectively, and significant ( P  < 0.05) reductions (0.94 log CFU g⁻¹ and 0.96 log CFU g⁻¹) in aerobes, and proteolytic bacteria in muscle on day 13. A significant ( P  < 0.05) inhibition of TMA-N formation after 9 days was also observed, with an average reduction of 28.4% along the storage period, Slight reductions in autolytic breakdown mechanisms were also observed in the ozonised batch, a maximum reduction of 14.82% being reached on day 13. The microbial and biochemical changes were well correlated with the sensory evaluation, which revealed relevant differences between the batches on day 13 and a shelf life extension of the ozonised batch up to day 16.