Fish is one of the principal protein sources in the human diet. From an economic standpoint, people want to meet their need for animal proteins from cheaper food. As a result of the increasing number of working women and rapid urbanization, the demand for ready-to-serve food products is rising. Ready-to-serve food products do not spoil for a period of time due to the processing techniques used. The natural antioxidant system is divided into two ma¬jor groups, enzymatic and non-enzymatic antioxidants. Regarding enzymatic antioxidants they are divided into primary and secondary enzymatic defences while the primary defence is composed of three important enzymes that prevent the formation or neutralise free radicals: glutathione peroxidase, catalase, superoxide dismutase and the secondary enzymatic defence includes glutathione reductase and glucose-6-phosphate dehy-drogenase.