Abstract
Sichuan-style meat products are typical representatives of traditional and characteristic meat products in China. Piper longum L. is one of the commonly used spices in its processing, and piperine (PIP) is one of its main alkaloid components. The interaction between myofibrillar proteins (MPs) and PIP was investigated using multispectral analysis, molecular docking, and molecular dynamics simulations. Fluorescence quenching mechanisms reveal that the fluorescence of PIP on MPs is static, demonstrating a strong binding affinity. Circular dichroism analysis shows that interaction enhances the α-helical structure of MPs. The particle size of the formed complex initially increased before decreasing, while zeta potential first decreased, then increased. Additionally, molecular docking and dynamics simulations disclose that non-covalent interactions (electrostatic forces, van der Waals forces and hydrophobic interactions) are pivotal to the PIP-MPs interaction, with ARG202 and PHE622 being the most significant amino acid residues involved. We found that PIP's methyldioxophenyl selectively disrupts disulfide bonds in MHC, while its piperidine cyclic amide bond system promotes structural rearrangement in MPs through π-π stacking and hydrogen bonding networks. This research provides a theoretical foundation for optimizing natural spice applications in Sichuan-style meat products.