Survey of trace elements content of Tilpia, catfish and salmon in the Virginia market: risk, nutritional assessment and selenium health benefit values (Se-PhHBV)

By Razieh Farzad (PhD student of Water IGEP, under direction of Dr. Kuhn), presented at World Aquaculture Society (WAS) on Feburary 2017

Elemental food composition data are important to both consumers and health professionals. Aquaculture industry has experienced growth in recent years with the new health and nutrition trends that emphasize importance of seafood in diet. Fish has been acknowledged as an essential component of 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 Virginia market were analyzed for levels of Na, Cu, Mn, Se, Ca, Fe, As, Mb, Cd, Pb and Zn. The potential human health risks for the consumers and the nutritional value in regards to their mineral content 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 health benefit value (Se-HBVs) were also calculated for each species.

In this study, microwave assisted acid digestion method was optimized for digestion of fish fillet. Samples were analyzed for aforementioned minerals using ICP-MS method. Method 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 the species analyzed showed beneficial Hg:Se ratios and Se-HBVs. the contribution of these fish to the Recommended Daily Allowance (RDA) and adequate intakes of these elements ranges from % 0.06(Se) to 20.% (Mg) for  an adult. Intake of these elements through these fish would not pose any risk for the average consumer. The 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.