الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Catfish is popular fresh water fish with an economically important group of fresh and brackish water fish worldwide several species have been successfully introduced in aquaculture. African catfish (Clarias gariepinus L.) is perhaps the most important one, not only in Africa but also in Asia and Europe. Due to catfish lower market price and its less quality attributes, it is not desirable for Egyptian consumers. This work was carried out to study the effect of freezing and smoking on the quality of catfish fillets during different methods of storage. Catfish fillets were treated with 2% rosemary oil (RO) and/or 5% sodium tripolyphosphate (STPP) then frozen at -40°C and storage at -18±1°C for eight months. Meanwhile, the other sample of catfish fillets was treated with 1, 3 and 5% of STPP thin smoked and stored at 4±1°C and 25±2°C for 30 days. The results indicated that throughout different storage periods, moisture, protein and fat contents of frozen and smoked catfish fillets were gradually decreased, while ash content was increased for all frozen and smoked samples. Trimethelamine nitrogen (TMAN), total volatile bases nitrogen (TVBN), peroxide value (PV) and thiobarbituric acid (TBA) levels were gradually increased in frozen and smoked fillets that stored at chilling throughout storage periods. Moreover, the increase was sharply in smoked fillets stored at 25±2°C. Also, results declared gradual decrease in all microbial counts except psychrophilic was increased in frozen samples while, in smoked samples all microbial counts were increased at the end of storage. The sensory scores were decreased during storage for all frozen and smoked samples. Finally, frozen fillets were treated with mixture of 2% RO+5% STPP showed the best quality at any given time of frozen storage up to the end. Cold-smoked catfish fillets treated with 5% STPP can be safely stored under refrigeration more over 30 and about 24 days under room temperature.