Mechanisms underlying the loss of anti-inflammatory activity in honey-processed licorice: a...

Thermal processing strongly influences the bioactivity of phytochemical-rich foods, but the mechanisms behind functional loss under different conditions are not well understood. We used honey-processed licorice as a model to explore the process-structure-function relationship by simulating the honey processing of four key compounds: isoliquiritigenin, liquiritin, glycyrrhizic acid, and 18β-glycyrrhetinic acid. UPLC-Q-TOF-MS/MS, molecular docking, dynamics simulations, DFT calculations, and RAW264.7 macrophage assays identified a narrow processing window where moderate glycosidic cleavage creates an optimal pool of fragments, while extended heating causes over-fragmentation. These fragments, but not over-cleaved ones, maintain multi-target engagement along the TLR4-MyD88-TRAF6-IKK/IκB-NF-κB signaling axis through a conserved 'anchor-clasp' motif, explaining why raw monomers are more effective than honey-processed ones in macrophages. Our findings provide a framework for optimizing thermal food processing to preserve the health benefits of functional ingredients.