Mercury and methylmercury content, fatty acids profile, and proximate composition of consumed fish in Cananéia, São Paulo, Brazil

ABSTRACT

Fifty three individuals of four most commonly consumed fish species by the Cananéia city population, in São Paulo, Brazil, were analyzedto determine total mercury (Total Hg) and methylmercury (MeHg) levels, as well as, proximate composition and fatty acid profile. Themuscle of three carnivorous species Centropomus parallelus (Fat snook), Macrodon ancylodon (King weakfish) and Micropogonias furnieri(Whitemouth croaker), and one planktivorous species Mugil platanus (Mullet) were analyzed. MeHg and Total Hg determinations wereperformed by Cold Vapour Atomic Absorption Spectrometry (CV AAS). Fatty acid profile was determined by gas chromatography (GC) whilst AOAC methods were used for proximate analysis. The total Hg results (interval) in wet weight basis were Whitemouth croaker(114–442 μg kg-1), Fat snook (15-178 μg kg-1), King weakfi sh (12-100 μg kg-1) and Mullet (<10–25 μg kg-1), and none of the fish species exceeded the Brazilian legislation limits. MeHg values were below FAO/WHO (2007) recommendations. In nutritional terms, the resultsfor proximate composition for all four fish species proved to be an excellent protein source with very low lipid content as was expected. Fatty acids of all fish species were adequate. Total polyunsaturated fatty acid contents varied from 21.9% (Micropogonias furnieri) to26.4% (Mugil platanus). For the n-3 family, Macrodon ancylodon presented the highest value (20.9%) and Micropogonias furnieri thelowest one (15.8%). Mugil platanus (Mullet) species also showed good levels for all parameters analyzed and very low concentrations of contaminants, indicating it as a good nutritional choice in terms of risks and benefits.