Trace metals in marine foodstuff: Bioavailability estimation and effect of major food constituents

A simulated in vitro digestion method for the dialyzability assessment of trace metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, V and Zn) from different seafood and edible seaweed has been developed. Inductively coupled plasma-mass spectrometry was used for metal determination in the dialyzates and in the samples after a microwave assisted acid digestion pre-treatment. Trueness of the procedure for total metal determination has been assessed by analyzing different certified reference materials (DORM-2, BCR 279 and NIES-09); whereas, trueness for the in vitro bioavailability method has been established after performing a mass balance study. Low (2.6–10.8%) and moderate (21.5–41.3%) dialyzability percentages have been found in seafood samples. However, high dialyzability percentages (30.0–74.7%) have been found in edible seaweeds. Linear and quadratic models have shown that the bioavailability of some metals exhibited good positive correlation with the carbohydrate content and also with the dietary fibre level. Protein content showed good negative correlation with the bioavailability of certain metals, whereas, moderate negative correlation was found with fat content.