The effect and mechanism of four drying methods on the quality of tilapia fillet products

Abstract

Tilapia (Oreochromis niloticus) holds a major position in the fishery market worldwide. This study aimed to investigate the effect of four drying methods, namely vacuum freeze (VFD), vacuum microwave (VMD), hot air (HAD) and microwave (MD), on texture, amino acids, microstructure, lipid oxidation and protein degradation of tilapia fillets. The results showed that vacuum combined with refrigeration (VFD) or VMD had better color, chromatic aberration, shrinkage ratio and microstructure. The total essential amino acid content (31.16%), α-helical (28.06%) structure and protein denaturation temperature of nonthermal VFD were higher than the VMD, HAD and MD methods. In thermal drying processing, VMD had some advantages in protein stability, microstructure, lipid oxidation and flavor compared with HAD and MD products. Therefore, a combined drying method was discovered to have prospects for use in tilapia processing. VFD was considered the appropriate nonthermal drying method of fillets with high product quality and protein stability. Meanwhile, considering the advantages of its efficiency, quality and energy consumption, the VMD had the best potential of the four methods employed to dry tilapia fillets.