β-Carotene (BC), a naturally occurring lipophilic carotenoid, is beneficial for human health. However, its water solubility and bioavailability are low. In this study, organogel-based nanoemulsion was successfully prepared to improve the loading amount, solubility, and bioavailability of BC. Corn oil was selected as the oil phase for the organogel as a result of the greatest release amount of BC. Tween 20 was optimized as the emulsifier based on the highest extent of lipolysis and BC bioaccessibility. The nanoemulsion was a better alternative than the organogel according to both the extent of lipolysis and BC bioaccessibility. Cellular uptake of BC was significantly improved through organogel-based nanoemulsion compared to BC suspension. Caveolae-/lipid-raft-mediated route was the main endocytosis pathway. Pharmacokinetic results confirmed that the in vivo bioavailability of BC in nanoemulsion was 11.5-fold higher than that of BC oil. The information obtained suggested that organogel-based nanoemulsion may be an effective encapsulation system for delivery of insoluble and indigestible bioactive compounds.
Keywords: bioaccessibility; bioavailability; organogel-based nanoemulsion; β-carotene.