Eugenol improves physical and chemical stabilities of nanoemulsions loaded with β-carotene

Food-grade nanoemulsions are potential vehicles of labile lipophilic compounds such as β-carotene, but much work is needed to improve physical and chemical stabilities. The objective of this work was to study impacts of eugenol on physical and chemical stabilities of β-carotene-loaded nanoemulsions prepared with whey protein and lecithin. The combination of whey protein and lecithin resulted in stable nanoemulsions with eugenol added at 10% mass of soybean oil. Nanoemulsions, especially with eugenol, drastically reduced the degradation of β-carotene during ambient storage, heating at 60 and 80 °C, and UV radiation at 254, 302, and 365 nm. The droplet diameter of the nanoemulsion without eugenol increased from 153.6 to 227.3 nm after 30-day ambient storage, contrasting with no significant changes of nanoemulsions with eugenol. Heating or UV radiation up to 8 h did not significantly change the droplet diameter. Therefore, eugenol can be used to improve the stability of nanoemulsion delivery systems.