Abstract:

Purpose: To investigate the process of β-carotene micellarization and evaluate the effect of oil droplet size, oilphase content and β-carotene concentration on the bioavailability of β-carotene incorporated in emulsions as well as toelucidate the possible mechanisms. Methods: The β-carotene bioaccessibility was assessed by in vitro digestion model. Thefraction of β-carotene transferred from the emulsion to a micellar phase was investigated. Results: Within the first 30 min ofduodenal digestion, the majority of lipid hydrolysis and β-carotene micellarization occurred. There was a negative correlationbetween the ratio of β-carotene incorporated into micelles and oil droplet size in the range from 0.44 to 4.28 μm. When theoil phase content increased from 1% to 20%, the bioaccessibility of β-carotene in the micellar phases presented a S-typegrowth tendency. The ratio of β-carotene incorporated into micelles increased significantly when β-carotene concentrationincreased from 2 to 30 mg/100 g and then tended to decrease when β-carotene concentration was further increased. However,the absolute amount of β-carotene incorporated into micelles increased first and then tended to remain stable.

Key words: emulsion, oil droplet size, β-carotene, high-pressure homogenization, in vitro digestion, bioaccessibility