Effect of Harvesting Techniques and Refrigerated Storage on the Quality of Nile Tilapia (Oreochromis niloticus) Fillets

This study was performed to investigate the effect of harvesting techniques and refrigerated storage on the quality of the Nile tilapia (Oreochromis niloticus) fillets. Two harvesting techniques were conducted; high water column (200 to 100cm) unstressed and appropriately harvested with live transported tilapia (LT), and low water column (up to 30cm) stressed harvested with iced transported tilapia (IT). Tilapia samples harvested by two techniques were filleted and stored at 5±0.5ºC in the refrigerator and analyzed after 0, 3, 6 and 9 days, respectively. Results indicate that the yield of fillets of LT was more than IT samples. For ITFs,  a gradual increase was recorded in the values of TBA, pH, and TVBN, associated with a gradual decrease in WHC compared to LTFs.  The sum of polyunsaturated fatty acids (PUFAs) decreased gradually, while the sum of both saturated (SFAs) and monounsaturated fatty acids (MUSFAs) increased with increasing the storage period, especially for ITFs relative to LTFs. In conclusion, tilapia fillets of the unstressed, appropriately harvested, and live transported tilapia (LTFs) showed a higher yield, longer shelf life, and better quality than the stressed-harvested and ice- transported tilapia (ITFs). Hence, this study recommends that transferring of harvested fish live in oxygenated water tanks is better than the other technique to prevent high economic losses and increase the profitability of tilapia processing in Egypt and all over the world.