Effects of cooking methods on the heavy metals, fillet proximate composition and fatty acid composition of Roach (Rutilus rutilus caspicus)

Fish is a potential source of vitamins and minerals and the cooking method play an important role in the final content of nutrients of it. The aim of the present study was to the effects of different cooking methods on the heavy metals, fillet proximate composition and fatty acid composition of Roach (Rutilus rutilus) fillet.

Four cooking methods such as deep frying, baking, steaming, and microwave cooking were applied on the fillet. Determination of the remaining heavy metals of the samples was carried out using atomic absorption. The proximate composition was assessed using the standard methods. To measure the composition of fatty acids, Gas Chromatography method (GC) was applied.

All treated samples had a significant decrease in moisture (frying) and ash (microwave) and a significant increase in fat (frying) and protein (baking). The polyunsaturated fatty acids (PUFA), ω‐3 fatty acids as well as EPA/DHA content increased in baked samples in comparison to raw fish fillets and other cooked. The frying process caused a significant increase in lead concentration content. While the steaming significantly decreased heavy metals concentration in comparison to raw fish fillets and other cooked.

Considering the increasing of EPA, DHA, and ω‐3/ω‐6 ratio in baked‐cooked and losses of heavy metals in steamed, these two cooking methods are the best cooking method for this type of fish and healthy diet.