Do Traditional Culinary Methods Alter the Lipid Content and Fatty Acid Profiles of Mytilus galloprovincialis?

The effect of five cooking methods (barbecue-grilling, boiling, microwaving, oven cooking and frying) on lipids and fatty acids composition (FAs) of the mussel Mytilus galloprovincialis was investigated. Moreover, in order to assess the nutritional quality of raw and cooked mussel, several lipid nutritional quality indices (LNQI) of dietary importance (e.g. the ratio polyunsaturated to saturated fatty acids, the ratio omega-3 to omega-6 index, the atherogenicity index, the thrombogenicity index, the hypo-cholesterolemic to hyper-cholesterolemic index, the health-promoting index, the unsaturation index, the flesh lipid quality and the polyene index), by determining the fatty acid composition, were studied. All cooked samples showed a significant decrease in moisture and increase in lipid content compared to raw mussel. Total lipids exhibited the highest value in fried product with 13.75 g/100 g wet weight.

All cooking treatments significantly (p < 0.05) modified the fatty acid profiles of mussels, showing major changes in fried samples, which exhibited the lowest saturated fatty acids (SFA) and n-3 polyunsaturated fatty acids (PUFAs) and highest n-6 PUFAs content. A significant decrease in the n-3 PUFA from the raw sample to five cooking methods was also observed. The n-3/n-6 ratio decreased from raw (6.01) to cooked mussels, exhibiting the lowest value in fried ones (0.15). Comparison of the LNQI of raw mussels with cooked ones, revealed that cooking caused significant changes in the nutritional indices, indicating a decrease of nutritional quality. However, all samples, raw and cooked, exhibited LNQI within the optimal range to meet the need of consumers. As a conclusion, except for frying, cooking does not damage the nutritional quality of mussels, despite the fact that it reduced the atherogenic and thrombogenic indices.