ANIMAL-DERIVED PRODUCTS AS SOURCE OF BIOACCESSIBLE XANTHOPHYLLS
Xanthophylls are oxygen-containing carotenoids associated with reduced risk of developing chronic diseases, including age-related macular-degeneration. Carotenoids are primarily consumed from fresh and processed fruits and vegetables but some animal-derived foods also present considerable amounts of such compounds. However, the estimative of carotenoid composition of food is not necessarily an indicative of the quantity of carotenoids that is accessible for absorption in the small intestine, which is considered bioaccessible. The aim of this work was to evaluate xanthophyll bioaccessibility in commonly consumed animal foods. Hard-boiled egg yolks and pan-fried wild salmon were subjected to in vitro digestion according to the INFOGEST method adapted for carotenoids. Lutein, zeaxanthin and astaxanthin were quantified by HPLC-DAD in homogenized samples, chyme and micellar fraction. Carotenoids were stable during digestion conditions (recovery > 85%). The efficiency of micellarization of astaxanthin in salmon was 36%, whereas lutein and zeaxanthin from egg yolk were, respectively, 83 and 90% bioaccessible. The highest carotenoid bioaccessibility observed in egg yolk was expected since this sample naturally presents high amounts of lipids, known to enhance carotenoid bioaccessibility. Moreover, carotenoids are found in a lipid-dissolved state in yolks, which likely contribute to their high efficiency of micellarization. Although the amount of astaxanthin in salmon (41.8 µg/g fw) was higher than those of lutein (15.4 µg/g fw) and zeaxanthin (11.8 µg/g fw) in egg yolk before the in vitro digestion, similar amounts of all the xanthophylls were found in micellar fractions (15.0, 12.8 and 10.6 µg/g fw for astaxanthin, lutein and zeaxanthin, respectively). In summary, both the animal products were ratified as source of bioaccessible xanthophylls that may play role in health-promoting activities in the body. To the best of our knowledge, this is the first time that the INFOGEST method was applied to study the carotenoid bioaccessibility in animal-derived food.