Insights into the dynamics of edible oil oxidation: From molecular interactions to oxidation kinetics

Current research investigates the impact of molecular organizations on the oxidation kinetics of canola oil under thermal and photo oxidation conditions. By combining experimental measurements with computational simulations, we provided a molecular perspective on the oxidation process. The findings revealed that higher temperatures resulted in shorter lag periods and faster oxidation rates, consistent with prior research. Interestingly, the photo oxidation system exhibited the shortest lag period but the lowest oxidation rate during the exponential phase, suggesting that initial oxidative stress alone cannot predict the oxidation stability of oils. Viscosity measurements further clarified differences in the lipid hydroperoxide (LOOH) self-assembly behavior between thermal and photo oxidation systems. We observed that temperature influenced micelle formation, with higher temperatures leading to higher critical micelle concentrations (CMC). Surprisingly, the calculated CMC in the photo oxidized system was significantly higher than in the thermally oxidized system. Such observation was explained by molecular dynamics simulations, in which stronger LOOH-water interactions in thermal oxidation compared to photo oxidation were revealed. Analysis of mean-square-displacement revealed higher LOOH diffusion rates in thermal oxidation compared with photo oxidation, at lower temperatures. These observations suggest that faster oxidation kinetics in thermal oxidation systems may be attributed to the stronger tendency of thermal oxidation LOOHs to self-assemble and their higher diffusion rates, which enable them to propagate the oxidation process throughout the oil. Overall, these findings contribute to a deeper understanding of oxidation kinetics in oils, offering valuable insights for the development of strategies to retard oxidation and preserve food quality.