Bioaccessibility in risk-benefit analysis of raw and cooked seabream consumption

The composition of raw and cooked gilthead seabream (Sparus aurata) was analysed. The bioaccessibility of arsenic (As), selenium (Se), mercury (Hg), and methylmercury (MeHg) in raw and cooked fish was studied by an in vitro model. A risk-benefit assessment was performed taking into account bioaccessibility. The content of contaminants Hg and As displayed a significant increase for every culinary treatment, only As content in boiled fish did not increase. Regarding bioaccessibility, while bioaccessible As was high (over 96%), the share of Hg (and MeHg) available for intestinal absorption was reduced by cooking, especially by grilling, 39% (60%) and roasting, 38% (55%). The risk-benefit probabilistic assessment leads to an advice of not exceeding one weekly meal of gilthead seabream. This recommendation concerns mainly pregnant and nursing women. However, Se bioaccessibility was high —minimum of 85% in boiled seabream—, thus helping to balance the deleterious effects of MeHg.Highlights: Hg & As increased for every culinary treatment with exception of As in boiled fish; As Bioaccessibility was always very high (exceeding 96%); MeHg bioaccessibility was lower after grilling, 60%, & roasting, 55%; Risk-benefit assessment leads to advising not exceeding one weekly meal of seabream; Se bioaccessibility exceeded 85% and balanced the deleterious effects of MeHg.This work was supported by the project “GOODFISH”, Ref. PTDC/SAU-ESA/103825/2008 and the individual Post Doctoral Grants for the authors Cláudia Afonso, Ref.: SFRH/BPD/64951/2009, and Carlos Cardoso, Ref.: SFRH/BPD/102689/2014, all of “Fundação para a Ciência e a Tecnologia” (FCT).