Encapsulation of vitamin D in gum arabic to enhance bioavailability and stability for beverage applications.

Delivery of vitamin D (VD ) in foods should exhibit desirable physicochemical characteristics and improves absorption. In this study, gum arabic (GA) was investigated as a VD carrier to encapsulate VD . VD dissolved in 5 mL ethanol corresponding to 0.3 to 6.0% mass of GA, was blended in 5.0% w/v GA solution, followed by freeze drying. The encapsulation efficiency decreased while loading capacity increased with an increased amount of VD . At the highest VD level, the loading capacity (3.47%) was the highest, and the encapsulation efficiency (61.24%) was satisfactory, and the treatment was further studied. The magnitude of negative zeta-potential increased from 3.1 to 31.0 mV at pH 2.0 to 7.4. During the 100-day storage at 3 °C of capsules reconstituted at pH 2.0 to 7.4, the hydrodynamic diameter decreased at all pH conditions, most evident for reduction to 81.3 nm at pH 7.4, and no precipitation was observed, indicating the significance of steric repulsion on capsule stability. Bioaccessibility of VD in capsules (95.76%) was significantly higher than the nonencapsulated VD (68.98%). The in vivo pharmacokinetic study in Sprague-Dawley rats after a single-dose of 300 µg VD showed the area-under-curve of serum 25(OHD) level in 48 hr of the encapsulation treatment was 4.32-fold of the nonencapsulated VD and more than twice higher than the VD -GA physical mixture. During 2-week supplementation of 60 µg VD /d, rats receiving capsules or physical mixture had 25(OH)D levels of at least 81 ng/mL higher than that of the nonencapsulated VD group. The studied encapsulation system holds great potential as a value-added ingredient to supplement VD in beverages with a wide pH range. PRACTICAL APPLICATION: The findings of this study demonstrated the improved dispersion stability and absorption of vitamin D after encapsulation in gum arabic. The capsules exhibited good dispersion stability across a pH range between 2.0 and 7.4, showing potential application in beverages. Furthermore, the enhanced absorption of VD after encapsulation highlights the nutritional benefits of the studied encapsulation system.