Abstract: Objective: The effect of precooling treatment with slurry ice on the quality change of fresh Japanese seabass was investigated during simulated circulation (precooling, transportation and storage). Methods: The fish were randomly divided into three groups: 1) precooling with slurry ice, transportation and storage (SI), 2) slurry ice precooling, transportation without ice and storage in crushed ice (SNI) and 3) precooling with crushed ice, transportation and storage (control). During storage, sensory attributes and physiological properties such as pH, salinity, texture profile analysis (TPA) and thiobarbituric acid (TBA) as well as total viable count (TVC) were measured at regular intervals. Scanning electron microscopic and sodium dodecyl sulfate polyacrylamide gel electrophoresis were performed. Furthermore, the quality change of Japanese seabass was evaluated. Results: The internal temperature of seabass was reduced to 0 ℃ by precooling with slurry ice for 1.0–1.5 h and the final temperature was ?1.1 ℃; the rate of temperature decrease was significantly higher than that of crushed ice treatment. Compared with the control group, SI maintained better sensory quality and texture properties, inhibited the increase in TBA, pH and TVC, and delayed the degradation of protein and muscle tissue during the mid-late storage period. The shelf-life of SI was about 18 d, which was 6 d longer than that of the control group. The fish in the SNI group were kept at a temperature below 0.8 ℃ during transportation without ice and no significant differences in texture properties, microbial quality or protein degradation were found compared with the control group. The shelf-life of both groups was 12 d. These findings suggested that slurry ice precooling could control temperature, thereby maintaining the quality of seabass. Conclusion: Slurry ice provides a rapid and efficient way to preserve aquatic products. SNI treatment can increase the loading amount of fish, thus cutting down the cost of transportation. The results of this study can provide valuable information for short-distance transportation of aquatic products during circulation.

Key words: slurry ice, precooling treatment, Lateolabrax japonicus, circulation