Enrichment of mayonnaise with plant-based antioxidants enhances phenolic bioaccessibility and oxidative stability

This study aimed to investigate the in vitro bioaccessibility and antioxidant activity of Satureja montana (SM) and Lavandula × intermedia (LI) plant extracts incorporated in mayonnaise. Ultrasound-assisted extraction from both plants was optimized via response surface methodology. HPLC-HRMS characterization of the optimal extracts showed high levels of rosmarinic, lithospermic, and salvianolic acids in SM and glycosylated hydroxycinnamates in LI. In a mayonnaise model, SM and LI extracts both extended oxidation induction time achieving an inhibition rate constant of 2.2 × 10 4 and 1.7 × 10 4 M −1 s −1 , respectively, both exceeding BHT (1.2 × 10 4 M −1 s −1 ). In vitro digestion of the enriched mayonnaise improved the bioaccessibility of phenolics and flavonoids by 285 % and 295 % for SM and 445 % and 280 % for LI. These findings demonstrate that oil-in-water emulsions preserve extracts functionality, and increase gastrointestinal release, supporting the application of plant-based extracts as natural antioxidants in functional foods. • Optimized extraction variables: time, ethanol concentration, ultrasound amplitude. • SM extracts had higher phenolic and antioxidant activity than LI. • Plant extracts showed potential as a natural alternative in mayonnaise model. • Mayonnaise model protected phenolics and improved in vitro bioaccessibility.