Comparison and determining the quality and evaluation of corruption of Frozen Fillets Tilapia Nile fish (Oreochromis niloticus) imported and cultured in Iran

One of the problems products produced of imported frozen fillets tilapia fish such as nuggets, bitterness of the products in during storage in freezing conditions. Since in this study, the quality of imported frozen fillets with fillets of tilapia that cultured in Iran, during two months was evaluated and the trend of corruption in the fillets was compared. According to the results of evaluation (proximate composition, thiobarbituric acid (TBARS), free fatty acids (FFA), Hypoxantin (HX), formaldehyde (FA), dimethyl amine (DMA), peptides soluble in trichloroacetic acid (TCA), protein solubility, electrophoresis and fatty acid profile) the DMA and TCA levels of imported fillets were 0.6 miligram DMA-N Per 100 g sample and 0.35 milimol tyrosine per g sample respectively, that were higher as compared to DMA and TCA cultured fillet zero time (0.2 miligram DMA-N Per 100 g sample and 0.18 milimol tyrosine per g sample respectively) and their protein contents was lower than cultured fillets (15.65 % in imported fillet and 18.60 % in cultured fillet). As a result, high levels of peptides and their production during subsequent processes in imported frozen fillets can be a source of bitterness for the products produced from them.