Impact of Lipid Content on the Ability of Excipient Emulsions to Increase Carotenoid Bioaccessibility from Natural Sources (Raw and Cooked Carrots)

The influence of lipid concentration on the ability of excipient emulsions to increase carotenoid bioaccessibility from raw and cooked carrots was investigated using a simulated gastrointestinal tract (GIT). Excipient emulsions were fabricated using whey protein as a natural emulsifier and a long chain triglyceride (corn oil) as a digestible lipid. Changes in particle size, charge, and microstructure were determined as the carrot-emulsion mixtures were passed through simulated mouth, stomach, and small intestine. Carotenoid bioaccessibility increased with increasing digestible lipid concentration in the excipient emulsions (from 0 to 8 %). Carotenoid bioaccessibility was higher from boiled carrots than for raw carrots, which was attributed to disruption of plant cell structure facilitating carotenoid release. In conclusion, excipient emulsions are highly effective at increasing carotenoid bioaccessibility from carrots, which can be attributed to the ability of the small lipid droplets to rapidly solubilize the carotenoids.