Structural Characterization of the Catechin–Papain Complex and Its Activity Toward Meat Tenderization

Papain is recognized for its cost-efficient meat tenderization. However, its strong tenderizing capability requires careful application to avoid a mushy texture. This work examines an innovative combination of papain with catechin to enhance meat tenderness while preserving the cooking yield. Papain was incubated with catechin, and the resulting precipitate was discarded. The remaining catechin–papain complex was subsequently analyzed using multispectroscopic methods, demonstrating activity across a broad pH range (3–9) and stability from 4 to 60 °C. The calculated bimolecular quenching constant suggests static quenching through hydrogen bonding and van der Waals interactions, which agrees with molecular docking findings. The marinated chicken samples displayed consistent pH levels, high cooking yields, and comparable protein solubilities. Overall, this combination significantly improves meat functional properties beyond those of individual treatments, and the laboratory-scale prototype warrants further investigation for enhanced meat tenderness in the food industry.