Effects of Different Processing Methods on the Preservation Effect of Tilapia Fillets

In order to extend the partially frozen storage time of tilapia fillets, the effects of temporary culture methods, different lethal methods, changing the sequence of partial freezing and vacuum packing, fillet thickness and vacuum degree on the partially frozen preservation effect of tilapia fillets were explored, and the sensory characteristics, water desorption rate and total volatile base nitrogen (TVB-N) in the course of storage were evaluated. The results showed that tilapias were best preserved by being temporarily cultured with 0.5% citric acid solution and shocked to death with 0℃ ice water. Tilapia fillets with the thickness of 10 mm had the lowest TVB-N value (191 mg·kg^-1) after partial freezing at -3℃ for 25 days. The water desorption rate of tilapia fillets was lower by adopting the method of vacuum packing before partial freezing. Therefore, if tilapias were temporarily cultured with 0.5% citric acid solution and then shocked to death with 0℃ ice water for 40 min, filleted into 10 mm thick, vacuum packed with -0.100 MPa and then partial freezed at -3℃, it would be conducive to the preservation of tilapia fillets.