Encapsulation of β-carotene in oleogel-in-water Pickering emulsion with improved stability and bioaccessibility

Abstract β-carotene (BC) is beneficial for human health. However, the low oxidative stability and bioavailability of hydrophobic BC limit its utilization as supplements in functional foods and pharmaceutical products. Herein a conventional oil-in-water Pickering emulsion (OPEs-1) and an oleogel-in-water Pickering emulsion (OPE-2) were prepared and determined to improve the chemical stability and bioavailability of BC. Cellulose nanocrystals were used as the emulsifier. Oleogel was developed by structuring soybean oil with beeswax. The freezing-thawing (FT) stability and physical stability of the OPEs-2 was improved compared to the OPEs-1. The OPE-2 seemed to be stable against three FT cycles. The OPEs-2 presented higher droplets size than OPEs-1, but they were more stable over a wide range of pH (4.0–8.0) and salt level (0.05–0.60 M). The chemical stability of BC encapsulated in OPEs-2 was higher than that in OPEs-1. For instance, the relative BC concentration decreased from 100% to 71.16%/90.12% in OPE-1/OPE-2 after stored at 25 °C for 15 days. The BC bioaccessibility in OPE-2 (68.17 ± 1.19%) was significantly improved compared with OPE-1 (53.15 ± 1.36%). The results obtained indicated that OPEs-2 was probably an effective delivery system for hydrophobic and indigestible bioactive compounds.