Reciprocal modulation between beef protein and wine phenolics during in vitro co-digestion: a proposed ternary complex-mediated mechanism modulated by cooking technique

Abstract

Background Beef and red wine form a classic dietary combination, yet how their components reciprocally influence each other during digestion remains unclear. Methods This study co-digested steamed, boiled and grilled beef with red wine using the INFOGEST 2.0 in vitro digestion model, combined with molecular docking, to investigate bidirectional modulation between beef proteins and wine phenolics. Results Wine co-digestion suppressed gastric carbonyl formation by 21.5%−30.8% and preserved free sulfhydryl groups by 27.7%−50.5% across cooking methods. Two-way analysis of variance indicated significant cooking × wine interactions for protein oxidation and amino acid release. The largest improvement occurred in grilled beef, whose gastric digestibility and intestinal amino acid content increased by 20.9% and 67.2%, respectively. Docking simulations predicted that selected phenolics bound to myosin heavy chain and pepsin through hydrogen bonding and hydrophobic interactions, supporting a proposed phenolics-pepsin-myosin ternary complex that may strengthen enzyme-substrate association. Reciprocally, the beef matrix enhanced ABTS antioxidant activity by 24.9% (gastric) and 125.3% (intestinal) relative to wine alone, and was associated with selective phenolic regulation: gastric gallic acid increased by up to 135.7%, whereas intestinal epicatechin and resveratrol rose up to 3.5- and 11.6-fold, respectively. Conclusion These findings support the proposed ternary complex as a plausible molecular hub governing protein–phenolic reciprocity, providing a proposed mechanistic basis for optimizing cooking methods and meat–wine pairing strategies in mixed meals.