Trade-off between chemical safety and bioactivity during cocoa roasting revealed by multivariate modeling.

Cocoa roasting triggers coupled thermal reactions that shape bioactive composition and promote neoformed contaminants (NFCs), but frameworks linking precursor dynamics and bioactivity remain limited. Here, multivariate relationships among Maillard precursors, physicochemical variables, bioactive descriptors and NFCs were evaluated during cocoa roasting at 110-130 °C across six roast progression (RP) stages. RP was the main driver of chemical change: sucrose decreased by >95%, while glucose and fructose peaked at RP1-RP2 (up to ∼2500 mg/g) before declining, alongside a decrease in asparagine to ∼0.1-0.2 mg/g. NFCs peaked at intermediate stages and then decreased with advanced roasting (40-95%), as did phenols, antioxidant activity (60-85%) and methylxanthines (∼90%). Pareto-PCA revealed a safety-bioactivity trade-off, identifying RP3-RP4 as relevant window. Partial Least Squares Regression showed that furfuryl alcohol (R2 = 0.83) and 5-hydroxymethylfurfural (R2 = 0.82) were well explained by information on precursors, physicochemical properties and bioactive compounds, while acrylamide (R2 = 0.34) remained poorly predictable.