Nutritional quality traits of raw and cooked Ark shell (Bivalvia: Arcidae): balancing the benefits and risks of seafood consumption

Biochemical composition and fatty acid profile of raw Ark shells (RA) were compared to Ark shells submitted to three different cooking methods (BA: baking in the oven; PF: pan-frying in butter and MW: cooking in a microwave). Moisture (%) was significantly higher in RA (79.66) with respect to PF (65.09), BA (48.63) and MW (47.02). Protein (mg/g of flesh) decreased significantly from 18.62 in RA to 15.40 in MW, 13.76 in PF and 13.33 in BA. However, lipids significantly increased in MW (43.32 mg/g of flesh) and PF (63.63 mg/g of flesh) with respect to RA (35.05 mg/g of flesh). Pan-frying affected considerably triacylglycerol (TAG) and the fatty acid composition (FA) of Ark shell flesh. The most changes occurred in saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid fractions after this process. The n-3 PUFA decreased significantly from RA (16.40 mg/g dry weight) to PF (10.02 mg/g DW). While, the opposite trend was observed for n-6 PUFA, revealing that this cooking method had considerable effects on the nutritional characteristics of this edible shellfish. The analysis of lipid peroxidation markers such as thiobarbituric acid reactive substances, free fatty acid and peroxide value confirmed that both heat treatment and time of cooking caused lipid degradation, which had been more accentuated during pan-frying treatment. For the populations who consume Ark shells occasionally or frequently, baking and microwave cooking could be then considered as wiser and healthier cooking methods since they conserve better the nutritional value of this marine product. The present study will be of practical value from a health perspective for Mediterranean populations.