Effects of drying methods on qualities and microstructure of tilapia fillet

Tilapia fillets were dried by hot-air drying, vacuum freezing drying and supercritical carbon dioxide drying and the effects of three drying methods on qualities and microstructure of tilapia fillets were investigated. Qualities (nutrition, microbe, sensory, rehydration, texture) and microstructure of tilapia fillets were determined and analyzed. The results showed that, compared with hot air drying and vacuum freezing drying, the content of crude protein of tilapia fillet was higher and the content of its crude fat was lower by supercritical carbon dioxide drying. Supercritical carbon dioxide drying had the better effect of sterilization than hot air drying and vacuum freezing drying. Shrinkage and rehydration rates of tilapia fillet by supercritical carbon dioxide drying were slightly less than those by vacuum freezing drying. But sensory, texture and microstructure of tilapia fillet by supercritical carbon dioxide drying were similar to those by vacuum freezing drying. The qualities of tilapia fillet by supercritical carbon dioxide drying were much better than those by hot air drying. From the view of drying economics, supercritical carbon dioxide drying of tilapia fillet is feasible. The results can provide a reference for choosing the drying method of tilapia fillet.