Unveiling synergistic antioxidant combinations for α-tocopherol in emulsions: A spectrophotometric-mathematical...

This study presents a novel method based on a spectrophotometric assay coupled with mathematical modeling (Weibull interactions modeling CAT) to evaluate synergistic interactions of antioxidants in an oil-in-water model emulsion. The approach addresses a major limitation in current assays by eliminating interference from pro-/antioxidant pathways induced by exogenous radical initiators or buffers, allowing for a more accurate assessment of antioxidant efficacy. Using the Weibull equation, key kinetic parameters (LagP, α, β) were extracted to characterize the impact of antioxidant combinations on lipid oxidation. Results showed that certain combinations, such as α-tocopherol with carnosic acid, dieckol, and myricetin, exhibited concentration-dependent synergistic effects. Among these, carnosic acid in equimolar ratios demonstrated particularly promising interactions. In contrast, ascorbic acid revealed antagonistic behaviour when combined with α-tocopherol. Additionally, the presence of ferrous ions significantly influenced antioxidant interactions, highlighting their role in modulating underlying mechanisms. Overall, carnosic acid and dieckol emerged as strong candidates for use in combination with α-tocopherol under specific conditions. This method provides a refined approach for screening antioxidant synergies and contributes to the development of more effective antioxidant formulations in emulsified systems.