Physical properties of oil-in-water nanoemulsions stabilized by OSA-modified starch for the encapsulation of lycopene

The principles of formation and stability of nutrient-loaded nanoemulsions have been extensively investigated in previous research. In this study, we focus on the impact of lycopene on the formation and physical properties of oil-in-water nanoemulsions stabilized by octenyl succinate anhydride (OSA) modified starch. Lycopene nanoemulsions were fabricated using high-pressure homogenization and using medium chain triglycerides (MCT) as carrier oils. The DSC and FTIR-ATR results showed lycopene was amorphous and was encapsulated in the nanoemulsion droplet successfully. When the lycopene concentration ranged from 0.1 wt. % to 0.5 wt. %, the particle size decreased significantly. Raman and NMR measurements suggested that lycopene molecules lie in the hydrophobic core of the O/W nanoemulsion droplets when the concentration of lycopene is low. As the lycopene loading increased, its molecules stretched into the O/W interface, strengthening the lateral packing of OSA molecules on the interfacial membranes, and then decreasing the mean particle diameters and improved the stability of nanoemulsions, which is consistent with the results of Turbiscan AGS stability analyses. In summary, the incorporation of lycopene and the interaction between the lycopene and OSA molecules play an important role on the physical properties of the nanoemulsions.