Fat content affects bioaccessibility and efficiency of enzymatic hydrolysis of lutein esters added to milk and yogurt

- We evaluated in vitro bioaccessibility of lutein esters added to dairy products.
- Fortified milk and yogurt provide similar lutein levels as fruit and vegetables.
- Only fat content affected in vitro bioaccessibility of lutein esters.
- Skimmed milk showed lower lutein micellization levels than other milks.
- Lutein esters were probably hydrolyzed by action of pancreatic lipase.

Addition of lutein to dairy products is an alternative that widens the range of foods which could be lutein sources. However, bioaccessibility is an essential aspect to be considered during the development of products with added bioactive substances. We evaluated the in vitro bioaccessibility of lutein esters added to milk and yogurt with different fat contents, and determined the efficiency of enzymatic hydrolysis of the esters during digestion. Bioaccessibility of lutein and efficiency of hydrolysis were significantly lower in skimmed products than semi-skimmed and whole products, indicating that a minimal amount of fat is required to allow micellization and hydrolysis. The efficiency of ester hydrolysis ranged between 12 and 35%, which was attributed to pancreatic lipase. Whole and semi-skimmed samples were shown to be good vehicles for the addition of lutein, since presented bioaccessibility indices (38.3-47.5%) are similar to those found in natural food sources of xanthophylls.