Consumption of fermented Cd and Pb contaminated wheat flour increases potential health risk

Fermentation can increase the availability of heavy metals in wheat flour, however, its effect on the health risk of heavy metal contaminated wheat flour has not been fully investigated. A contaminated wheat flour (Pb = 0.26, Cd = 0.35 mg kg⁻¹) was fermented with yeast at 30 °C for 1 h, made into mantou and fed to mice for 14 days; a control without fermentation was also utilized. The mouse organ/tissue and feces were analyzed for Pb, Cd, Cu, Mn, Ni and Zn concentrations, and phytate concentrations of the fermented and unfermented wheat flour were also measured. Results indicated that mice fed contaminated fermented flour had 100 % greater liver and kidney Cd concentrations, and significantly greater liver Zn (9.40 %), kidney Pb (40.3 %) and Ni concentrations (40.6 %) than mice fed contaminated unfermented flour. Cadmium relative bioavailability of the contaminated fermented flour was 100 % greater than that in the contaminated unfermented flour. Thirteen days post-metal exposure, significantly lower Cd and Mn concentrations were found in feces from mice fed contaminated fermented flour than unfermented flour. Overall, results suggest a potential increased health risk of Pb and Cd contaminated wheat flour consumption following fermentation.