The molecular nature of interactions between β-casein and p-coumaric acid was studied following exposure of their solutions to ultra-high temperature (UHT at 145 °C). Interactions were characterised by employing multi-spectroscopic methods, molecular docking and quantum mechanics calculations. FTIR demonstrates that the ligand lies in the vicinity of the protein, hence inverting the absorbance spectrum of the complex. This outcome changes the conformational characteristics of the protein leading to a flexible and open structure that accommodates the phenolic microconstituent. Results are supported by UV–vis, CD and fluorescence quenching showing considerable shifts in spectra with complexation. Molecular docking indicates that there is at least a hydrogen bond between p-coumaric acid and the peptide backbone of isoleucine (Ile27). Quantum mechanics calculations further argue that changes in experimental observations are also due to a covalent interaction in the protein-phenolic adduct, which according to the best predicted binding pose involves the side chain of lysine 47.

在β-酪蛋白和对-香豆酸之间的相互作用暴露于超高温（145°C的超高温）后，研究了它们的相互作用的分子性质。通过使用多光谱方法，分子对接和量子力学计算来表征相互作用。FTIR证明配体位于蛋白质附近，因此反转了复合物的吸收光谱。该结果改变了蛋白质的构象特征，导致了适应酚微成分的柔性和开放结构。UV-vis，CD和荧光淬灭法支持结果，显示复杂络合的光谱发生了显着变化。分子对接表明p之间至少存在一个氢键-香豆酸和异亮氨酸的肽主链（Ile27）。量子力学计算进一步证明，实验观察结果的变化也归因于蛋白质-酚类加合物中的共价相互作用，根据最佳预测的结合姿势，赖氨酸47的侧链参与其中。