Dual role of phloretin in inhibiting 2-amino-3-methylimidazole[4,5-f] quinoline (IQ) formation and modulating flavor in a Maillard reaction model system

IQ (2-amino-3-methylimidazo[4,5-f]quinoline), a heterocyclic aromatic amine (HAA) formed via the Maillard reaction in thermally processed foods, poses safety concerns. Polyphenols can inhibit HAAs and modulate flavor, but their dual efficacy and IQ-flavor interplay are limited. This study identified phloretin as the most potent IQ inhibitor (70.27 % reduction at 0.5 mmol/L) among the nine candidates in chemical model systems; it impacts precursors and key carbonyl intermediates and significantly suppresses pyrazine formation. Chemical calculations confirmed that hydroxyl/carbonyl oxygens and aromatic rings are potential active sites. The correlation of the precursor and intermediate products demonstrated that the distinctive acyclic carbon bridge structure of phloretin enables multiavenue inhibition by reducing precursor reactivity and critically scavenging essential carbonyl compounds, thereby blocking synthetic pathways and reducing IQ/pyrazine yields. This research reveals the structural basis for the synergistic coregulation of safety and flavor by phenolics during the Maillard reaction, providing a new strategy for developing dual-function food additives for hazard mitigation and flavor preservation.