The synergistic inhibitory effect of co-digestion of gallic acid, catechin, β-glucan on lipid digestion in vitro.

This study explored the innovative mechanism of polyphenol-polysaccharide coordination in inhibiting lipid digestion during co-digestion of gallic acid (GA), catechin (CA), and β-glucan (BG). Among all co-digestion patterns, the CA + BG combination emerged as the most effective inhibitor, based on its lowest average FFA release rate and lowest FFA amount. The underlying mechanism involves pancreatic lipase (PL) activity suppression, coupled with viscosity-induced both stability of colloidal systems and molecular interactions. Polysaccharide-polyphenol interactions reduced emulsion stability via zeta potential reduction and post-digestion particle aggregation. CA/GA altered PL conformation through non-catalytic binding, inducing structural loosening (UV red shift 280 → 313 nm) and unfolding (fluorescence blue shift 340.8 nm), with BG potentiating these effects. Synergy analysis confirmed CA + BG's superior coordination (γ = 0.40, IC50 = 1.05 mg/mL). CA + BG interacted with non-catalytic sites of PL via hydrogen bonding and hydrophobic forces, supporting a non-competitive inhibition mechanism. Multi-component interplay governs inhibition efficacy, providing a new paradigm for designing lipid digestion modulators.