Interaction between tocopherols and phytosterols in vegetable oils and their antioxidant effects: A multi-scale investigation using molecular simulation and machine learning

The antagonistic effect of tocopherols and phytosterols was verified in three typical plant oil systems. • The antagonism mechanism where phytosterols disrupt tocopherol-triglyceride interactions was revealed. • A multi-scale framework was established to link molecular mechanisms with macroscopic performance. This study elucidates the interaction mechanism between tocopherols and phytosterols in vegetable oils and its influence on oxidative stability. The bond dissociation enthalpy (BDE) of α/γ-tocopherol and four phytosterols were calculated by density functional theory. It was found that the BDE of tocopherols were significantly lower than those of phytosterols, indicating the superior antioxidant activity of tocopherols. Molecular dynamics simulations show that the presence of phytosterols weakens the interaction between tocopherol and triglycerides, and the hydrogen bond density related to tocopherol in the system decreases. The experimental results further confirmed that the tocopherol-phytosterol combination exhibits a significant antagonistic effect. Furthermore, machine learning models with high accuracy (≥0.95) were constructed to predict the antioxidant performance of vegetable oils. These findings reveal the microscopic mechanism by which phytosterols interfere with tocopherols/triglyceride interaction, providing a theoretical basis for the combined application of antioxidants in vegetable oils.