Carotenoid Bioaccessibility and Caco-2 Cell Uptake Following Novel Encapsulation Using Medium Chain Triglycerides

Carotenoids are especially hydrophobic and dissolve poorly in water. Encapsulation is used to increase their solubility in water-based food products. However, it is not yet known whether encapsulation with a combination of lecithin and medium-chain triglycerides improves carotenoid bioaccessibility and intestinal cell uptake. The relative bioaccessibility and Caco-2 cell uptake of two water-soluble carotenoid (i.e. lutein and astaxanthin) dispersions in a liquid form (VitaSperse^®) and a powdered form (VitaDry^®) were compared to the carotenoid ingredient alone. An in vitro digestion model was used to assess bioaccessibility, measuring the micellarized fraction postdigestion. The micelle fraction was incubated with Caco-2 cells to assess intestinal uptake of carotenoids. Encapsulation (by either VitaDry^® or Vitasperse^®) increased total astaxanthin bioaccessibility 2-2.4× and cell uptake by ∼2× relative to control. Encapsulation also increased total lutein bioaccessibility by 3-5× and cell uptake 2.3× relative to control. There was no significant difference between VitaDry^® and VitaSperse^® products in regards to Caco-2 cell uptake. Increased bioaccessibility largely drove increased carotenoid cell uptake from the encapsulated formulations. These results suggest further study is warranted to determine if this encapsulation approach increases carotenoid bioavailability in human studies.