Quality and protein degradation of golden pompano (Trachinotus blochii) fillets during four drying methods

Abstract

Golden pompano (Trachinotus blochii) fillets were dehydrated by four drying methods including vacuum freeze (VFD), vacuum microwave (VMD), hot air (HAD), and microwave (MD) drying in this study. The quality, water distribution and states, protein degradation of dried fillets were determined. VFD fillets had looser microstructure and higher contents of protein (62.72 g/100g) than VMD, HAD and MD, while the VMD fillets had the highest lipid content (15.13%). The transverse relaxation time of immobilized water significantly decreased during the drying process, and the water content was uniform during VFD and VMD compared with MD and HAD processes. In addition, regarding protein degradation, VFD maintained a higher ratio of α-helical structure and higher protein denaturation temperature compared to the heating process (VMD, HAD and MD). Thus, VFD was considered as the appropriate non-thermal drying method of golden pompano fillets with the advantages of high product quality and protein stability. And in the thermal drying processing, the VMD fillets had better quality and higher efficiency.