Effect of high-voltage electrostatic field combined with composite preservatives on quality changes in rainbow trout during ice-temperature storage

Abstract To investigate diverse preservation techniques on aquatic products quality during storage, this study selected the rainbow trout as a representative. Total volatile basic nitrogen (TVB-N), total viable count (TVC), pH, and drip loss rate were used as key indicators. Preservation effects of four preservation methods were compared, including cold storage (4 °C), ice-temperature storage (−1 °C), high-voltage electrostatic field (HVEF, 3 kV/m) + ice-temperature storage (−1 °C), and composite biological preservative (CBP, 1.4% chitosan + 0.05% lysozyme + 1.3% tea polyphenols) + HVEF (3 kV/m) + ice-temperature storage (−1 °C). Results showed that the synergistic treatment with CBP and HVEF could effectively inhibit microbial growth. Samples under cold storage and ice-temperature storage had already decayed by day 10 (TVC: 7.12 lg(CFU/g)) and day 12 (TVC: 7.13 lg(CFU/g)), respectively. The TVC values of the HVEF+ice temperature and CBP+HVEF+ice temperature groups were only 6.32 and 5.89 lg(CFU/g) on day 12, respectively. On day 14, the TVB-N of the CBP+HVEF+ice-temperature group was only 20.17 mg/100 g, significantly lower than others. This study demonstrates that the preservation technology of CBP+HVEF can significantly delay the spoilage of fish and extend the shelf life of rainbow trout by 4 days.