Effects Lead Ions of on the Maillard Reaction in Flour: Implications for Heavy Metal Decontamination

Background The Maillard reaction is responsible for color and flavor development in baked goods and has been proposed as a potential mechanism for heavy metal sequestration due to the chelating capacity of melanoidins. This study investigated the influence of lead ions on the Maillard reaction under simulated bread-making conditions. Methods A glucose–lysine model system (pH 6.5) was heated at 100°C for 60 minutes in the presence or absence of 0.5 mg/L Pb²⁺. Browning development was monitored by measuring absorbance at 450 nm. Data were statistically analyzed using two-way analysis of variance followed by Tukey’s post hoc test. Results Lead ions significantly inhibited browning intensity at all time points, reducing absorbance values by 66–76% compared with controls (p < 0.001). Time-dependent browning was observed only in control samples, whereas Pb²⁺-treated systems showed no significant progression. Conclusion Pb²⁺ strongly suppresses the Maillard reaction, likely through sequestration of lysine or masking of reactive carbonyl groups, preventing early-stage Schiff base formation. Although partial metal binding may occur, the severe loss of sensory attributes limits the feasibility of Maillard-based lead decontamination in flour systems.