Influence of bioaccessibility of total mercury, methyl-mercury and selenium on the risk/benefit associated to the consumption of raw and cooked blue shark (Prionace glauca)

• Se bioaccessibility was high in blue shark.
• Hg bioaccessibility was lower in cooked blue shark compared to raw.
• For the bioaccessible fraction, all molar MeHg:Se ratios >1 and all Se-HBV negative.
• A yearly meal of blue shark presents very low risk.

This study aimed to identify the benefit and risk associated with raw and cooked blue shark consumption taking into account the bioaccessibility of Se, Hg and MeHg, by using in vitro digestion method. Selenium, Hg and MeHg levels were higher in cooked samples, particularly in grilled blue shark. Whereas Se bioaccessibility was above 83% in grilled samples, Hg and MeHg bioaccessibility was lower in grilled samples with values near 50%. In addition, all Se-Health Beneficial Values were negative and the molar MeHg:Se ratios were higher than one. The risk-benefit assessment yielded a maximum consumption of one yearly meal for raw or cooked blue shark, thus emphasizing the need to recommend the consumption of a wider variety of seafood species in a balanced and healthy diet.