Preliminary study into the factors modulating β-carotene micelle formation in dispersions using an in vitro digestion model

β-Carotene is an active compound associated with prevention of heart disease, cancer and cataracts. For absorption in vivo, β-carotene must be incorporated in mixed micelles. Micelle formulation varies widely and depends on various factors. The aim of this study was to identify and study the main factors governing the bioaccessibility of β-carotene incorporated into dispersions, using an in vitro digestion model. β-Carotene dispersions were prepared by high-pressure homogenization or by combining emulsification and evaporation. The average particle sizes of the dispersions obtained ranged from 45 to 18315 nm. Results show that the concentration of β-carotene, bile extract and pancreatic lipase, pH, and the particle size of the dispersions significantly affected the transfer of β-carotene from dispersions into micelles. The transfer of β-carotene was inversely related to the particle size and the concentration of bile extract and was highest at pH 6 and 0.4 mg/mL pancreatic lipase. Bile salt played different roles depending on the particle sizes of the dispersion. When the mean diameter of β-carotene particle was below 100 nm, the addition of bile extract and pancreatic lipase did not significantly affect bioaccessibility of β-carotene passing through in vitro digestion model. At larger particle sizes, the transfer efficiency of β-carotene increased with bile extract concentration. The outcomes suggest that there is potential to improve the bioavailability of β-carotene by micronizing lipid droplets.

We have identified the effect of the addition of bile extract and pancreatic lipase, pH, β-carotene concentration and dispersion particle size on the bioaccessibility of β-carotene dispersions using a in vitro digestion model. Results indicate that the initial particle size of the dispersion significantly influences the bioaccessibility of β-carotene. The smaller the particle size, the higher the transfer of β-carotene, suggesting that controlling particle size has potential for improving the bioavailability of β-carotene. Meanwhile, it is interesting to note that the transfer efficiency of β-carotene from the two nanodispersions used in the present work was significant higher than in micro-scaled dispersions, and was not affected by the presence of bile salt and pancreatic lipase.Figure optionsDownload as PowerPoint slide