Domiszewski, Bienkiewicz, and Plust (2011) have reported that boiling (without salt) had no effect on the total n-3 content and other cooking methods (boiling with salt, microwave cooking and frying) caused significant reduction. It seems that oil absorption by fish is the most important factor reducing the total n-3 content during frying.The effect of other cooking methods (boiling, frying and microwave cooking) on the reduction of n-3 content depends on the fatty acid composition and their sensitivity to oxidation. Testi et al. (2006) defined PI (peroxidisability index) for evaluating the relationship of fatty acid composition and its sensitivity to oxidation as follows: PI = (0.025 × monoenes) + (1 × dienes) + (2 × trienes) + (4 × tetraenes) + (6 × pentaenes) + (8 × hexaenes).