Antioxidant properties of ferulic acid-based lipophenols in oil-in-water (O/W) emulsions

Butyl ferulate (BF) and octyl ferulate (OF) were investigated to enhance oxidative stability of 1.0% vegetable oil-in-water (O/W) emulsions at pH 3.5 and 7.0 at different concentrations (5, 10, 15, 20, and 25 mg/L of emulsion). Particle size distribution, droplet surface charge, hydroperoxides (PV), hexanal and nonanal were monitored for 14 days at 35 °C. Higher concentrations of BF and OF generated smaller particles at pH 7.0 but not at pH 3.5. Control showed the highest negative surface charge (−58.38 ± 0.31 mV, pH 7.0) compared to BF and OF (−46.71 ± 0.06 mV at levels >0.10 mg/L). Both alkyl ferulates counteracted lipid oxidation, especially at pH 3.5, where PV decreased up to 96% compared to the control and delayed hexanal and nonanal formation. A low content of lipophenols allowed to achieve a tremendous shelf-life extension, demonstrating that BF and OF could be of great interest for food application.