β-carotene bioavailability from differently processed carrot meals in human ileostomy volunteers

Abstract

Background: Carotenoids contribute to the beneficial effects of fruits and vegetables consumption; however, the bioavailability of these compounds from fresh or processed foods is not well established. Aim of the study: We evaluated the bioavailability of β-carotene (15 mg) from a single meal composed of cooked, pureed carrots and compared it to raw, chopped carrots. Methods: Test meals were given to overnight-fasted-ileostomy volunteers (n = 8) along with skimmed-milk yogurt containing 40 g of added sunflower oil. Blood and complete ileal effluent samples were collected over a 24 h period. Samples were solvent-extracted and the β-carotene content measured by HPLC. Results: Kinetics of excretion of cis and trans β-carotene were similar. More β-carotene was absorbed from puree as compared to raw carrots. Carotenoid mass-balance calculations indicated that 65.1 ± 7.4% of the β-carotene was absorbed from cooked pureed carrot meals, vs. 41.4 ± 7.4% from raw, chopped carrot meals. Gastrointestinal transit parameters did not differ significantly among the volunteers. As expected, the calculated lag phase was five times longer for raw vs. cooked carrots. Mean t-end, t-1/2 and rate of mass transit resulted in similar values for both raw and cooked carrot meals. A moderate response in carotenoid plasma profile was observed for cooked carrot test meals. Conclusions: Significantly more β-carotene was absorbed from meals containing cooked, pureed carrots than from meals containing the raw vegetable. Moderate carotenoid plasma response was detected within 6 h following the administration of cooked processed carotenoid-containing single meal.