Characterization of the interaction between capsaicin and porcine myofibrillar proteins

Flavor binding or release behavior acts as an important role in the sensory characteristics of meat products. The interaction between capsaicin and porcine myofibrillar proteins (MPs) was investigated using spectroscopic methods and molecular docking simulations. The capsaicin quenched the fluorescence of MPs via static quenching mechanisms, indicating the interaction between MPs and capsaicin. The binding constant (1.20 × 105, 3.98 × 105 and 16.98 × 105 L/mol for 298, 303 and 310 K, respectively) and the number of binding sites (1.57, 1.74 and 2.01 for 298, 303 and 310 K, respectively) for capsaicin binding to MPs increased with the increase of temperature. Fluorescence and Raman spectroscopic analyses suggested that capsaicin exhibited no obvious effect on the conformation of MPs. The thermodynamic analysis revealed that interactions between capsaicin and MPs were spontaneous processes. The positive ΔH (169.05 kJ/mol) and ΔS (0.66 kJ/(mol·K)) indicated that the binding of capsaicin to MPs was predominantly driven by hydrophobic force, which was further corroborated by molecular docking simulations. The study provides insights into the mechanism of the interaction between capsaicin and MPs, which can guide the modulation of the spicy flavor during the meat processing to improve the sensory characteristics of meat products.