SURVEY OF TRACE ELEMENTS CONTENT OF TILPIA, CATFISH AND SALMON IN THE VIRGINIA MARKET: RISK, NUTIRTIONAL ASSESMENT AND SELENIUM HEALTH BENEFIT VALUES (Se-HBV)

Elemental food composition data are important to both consumers and health professionals because they are useful for improving dietary guidelines. The aquaculture industry has experienced rapid growth in recent years with health and nutrition trends that emphasize the importance of dietary seafood.  Fish has been acknowledged as an essential component of a well-balanced diet and is an important source of minerals. However, determination of trace elements in complex matrices, such as food, often requires extensive sample preparation and/or extraction regimes prior to instrumental analysis. Traditional techniques for sample preparation are time consuming and require large amounts of reagents, which are expensive, generate hazardous waste, and might contaminate the sample with the analytes. In this study, a total of 12 fresh and frozen samples of the commercial catfish, tilapia and salmon available in the Virginia market were analyzed for levels of As, Ca, Cd, Cu, Fe, Mb, Mn, Na, Pb, Se, and Zn.  The potential human health risks for the consumers and nutritional values of the minerals were assessed. Since Se has high binding affinity to Mercury (Hg) and many researchers have demonstrated the antagonist interaction of Se and Hg in different animal models, the mercury-selenium ratios and the selenium Se-HBVs were also calculated for each species. Se-HBV shows both absolute and relative amount of Se an Hg in the diet. Positive Se-HBV is indication of no health risk.

Microwave assisted acid digestion method was optimized for digestion of fish fillet. Samples were analyzed for aforementioned minerals using ICP-MS. Methodology was verified by analysis of fish protein standard reference material for trace element analysis (DORM-4). Potassium (K) presented the most remarkable concentrations of these elements. The highest concentration of the essential metals analyzed was found for catfish. All species analyzed showed beneficial Hg:Se ratios and Se-HBVs (Table1) the contribution of these fish to the Recommended Daily Allowance (RDA) and adequate intakes of these elements for adults ranged from 0.06% (Se) to 20% (Mg).  Intake of these elements through these fish would not pose any risk for the average consumer. Information regarding the trace metal content of fish from this study can be used in developing new aqua feeds to enhance fish production while providing consumers a product that is healthier to consumer.