Effect of a Preservative Mixture Consisting of Chitosan and Chlorogenic Acid Composite on the Eating Quality of Refrigerated Catfish Fillets

The catfish fillets were soaked in sterile water (CK), 3.0 mg/mL chlorogenic acid (CGA) solution, 1.0 mg/mL chitosan (CTS) solution, or a mixed solution of 3.0 mg/mL CGA and 1.0 mg/mL CTS (C +) and stored at low temperature. The effects of the CTS-CGA preservative mixture on the eating quality of catfish fillets were analyzed by comparing the changes in cooking loss rate and the changes in shear force, microstructure, water distribution and volatile components of cooked fish fillets as a function of storage time. The results showed that with increasing storage time, the cooking loss rate of catfish fillets increased; for cooked fillets, the shear force decreased, the arrangement of muscle fibers changed from ordered to disordered, and the mobility and relative content of water decreased gradually. After 6 days of storage, the relative content of off-flavor substances was markedly higher in the CK group than in the C + group. The relative contents of hexanal and trimethylamine in the CK group were 40.11% and 8.87%, respectively. The relative content of hexanal in the C + group was only 5.33%, and no trimethylamine was detected, indicating that the CTS-CGA preservative mixture could effectively inhibit the production of undesirable flavor. In conclusion, the CTS-CGA preservative mixture can effectively delay the texture deterioration and maintain the eating quality of catfish fillets.