Bioaccessibility assessment of Mn, Cu, Fe, and Cd in Henan Province wheat using physiologically based extraction

As an important crop in China, wheat serves as a crucial source of micronutrients and a potential vector for toxic elements in human diets. This study systematically collected wheat grains from 54 counties in Henan Province and conducted in vitro physiological extraction experiments to assess the bioavailability of Mn, Cu, Fe, and Cd in wheat samples. Results turned out that the bioavailability of Cd significantly decreased from the gastric to the intestinal stage. The bioavailability of Mn exhibited similar trends to Cd in the two phases, whereas Cu and Fe showed a higher bioaccessibility in the intestinal phase compared to the gastric phase. Correlation analysis revealed that higher total metal concentrations always resulted in a higher bioaccessible fraction, and the bioaccessibility of Cd was positively correlated with Mn and its bioaccessibility. Eventually, health risk to Cd from wheat consumption evaluated by Monte Carlo simulation indicated that children exhibited a heightened vulnerability to health risks in comparison to adults and risks could be decreased significantly by introducing bioaccessibility. Consequently, it is evident that refining the relationship between bioaccessibility and biotoxicity of elements could provide the methodology to accurately and efficiently assess human health risks.