(P01-011-23) Carotenoid Encapsulation Increases Astaxanthin Ester and Lutein Ester Bioaccessibility and Caco-2 Cell Uptake

Objectives: Fat-soluble nutrient encapsulation with a mixture of lecithin and medium chain triglycerides can improve solubility in aqueous food products. However, it is uncertain if such an encapsulation approach will improve bioaccessibility and intestinal cell uptake of carotenoid esters. It is also not known spray-drying of this product (producing a powder) influences bioaccessibility and cell uptake of carotenoid esters, relative to the aqueous-based product. We sought to determine if novel encapsulation of carotenoid esters improves bioaccessibility and Caco-2 cell uptake, relative to a non-encapsulated carotenoid ester oleoresin control.

Methods: Lutein and astaxanthin ester-rich oleoresins were tested separately in these experiments and served as our positive controls. They were tested with an aqueous encapsulated product (VitaSperse) and powdered encapsulated product (VitaDry) formulation by digesting with 100 mg soybean oil. In vitro gastric, duodenal, and jejunal digestion were mimicked for 1 hour each, with cholesterol ester lipase added during the intestinal phase. Following digestion, the micellular fraction was isolated, and mixed with media, and then incubated with differentiated Caco-2 cells for 4 hours at 37 °C. Chyme, micelle, and cell extracts were made using nonpolar solvents, and analyzed using high performance liquid chromatography-diode-array detection equipped with a C30 column. External calibration curves were used for quantitation. ANOVA followed by Tukey's post-hoc test was used to evaluate differences (P < 0.05 considered statistically significant).

Results: Vita products increased astaxanthin bioaccessibility 2-2.5x, relative to control. VitaDry and VitaSperse improved astaxanthin cell uptake 2.2x and 1.9x, respectively, compared to control. The Vita products also increased lutein bioaccessibility by 2.4-3x, compared to control. The Vita products also improved lutein cell uptake by ~1.9x as compared to control (with no difference between VitaDry and VitaSperse).

Conclusions: The novel encapsulation approach not only functions to improve lutein- and astaxanthin-ester solubility, but also to increase bioaccessibility in an in vitro model of digestion and subsequent Caco-2 cell uptake.

Funding Sources: This work was supported by a research grant from 3i Solutions, Inc.