Abstract:In this study, the temperature changes of catfish fillets in the processes of actual e-commerce logistics and simulated logistics were measured, and the effects of different termination temperatures on the quality of pre-frozen catfish fillets during cold storage were investigated. By simulating the temperature changes of catfish fillets in the actual e-commerce logistics with different transportation distances involving different ice amounts, packaging materials and environmental temperatures, it was found that the termination temperature of frozen catfish fillets in the logistics was between 0 ℃ and 8 ℃. Three e-commerce termination temperatures (0, 4, 8 ℃) were set in the experiment to simulate the continuous refrigeration of catfish fillets. The results showed that with the extension of storage time, drip loss, b* value, trimethylamine content, thiobarbituric acid (TBA) content, total volatile base nitrogen (TVB-N) content, freshness (K value) and total viable count of catfish fillets increased significantly, with the pH value and color being affected insignificantly. In addition, when the termination temperature of cold stored catfish fillets was 0 ℃, the tenderness, trimethylamine content, TBA content, TVB-N value and K value were the lowest, followed by the catfish fillets with the termination temperature at 4 ℃, whereas, the total number of bacteria reached 7.12 lg CFU/g (which exceeded the maximum safety limit value of fresh fish, indicating the fish was not suitable for intake), when the cold storage was longer than 6 days and had a termination temperature of 8 ℃. The termination temperature at the end of e-commerce logistics would influence greatly the quality of refrigerated products in the later period. The lower the termination temperature is, the slower the deterioration of quality in the later refrigeration period would be.
