Regulating protein structure by Ligustrum robustum (Rxob.) Blume polyphenols during thermal processing: A potential strategy

The effects and mechanism of polyphenols, identified from Ligustrum robustum (Rxob.) Blume, on the structure of myofibrillar protein (MP) and pea protein (PP) during thermal processing were investigated. The thermal analysis revealed that polyphenols enhanced thermal stability of MP while reducing that of PP. Multispectral analysis showed PP required lower polyphenol concentrations for fluorescence quenching than MP, while elevated polyphenols reduced MP's random coil structures but increased PP's. Computational simulation demonstrated that polyphenols had more binding sites with PP but more hydrophobic interactions with MP. Furthermore, polyphenols improved fried protein foods' texture and microstructure by regulating proteins' structural changes during processing. The findings clarified the regulatory effect of L.robustum polyphenols on different protein structures at high temperatures, which altered MP and PP structures through distinct molecular interactions. The present results provide a new perspective for using LRE polyphenols to improve the quality and safety attributes of protein-based foods.