Preparation, characterization and slow-release behavior during in vitro digestion of rice porous starch-based microencapsulated camellia oil.

Microcapsules laden with camellia oil (CO), utilizing rice porous starch (PS) as the core material carrier, were successfully prepared through spray drying, employing whey protein isolate (WPI) and maltodextrin (MD) as composite wall materials. This study delved into the rheological characteristics, zeta potential, and physical stability of the CO emulsions. The results indicated a notable reduction in the apparent viscosity of the CO emulsions upon the incorporation of MD. During the WPI and MD compounding process, the W7M3 emulsions system exhibited optimal particle interactions, deformation resistance, and physical stability. Furthermore, the formation process, structural properties, and in vitro simulated digestion and release behaviors of various PS-based CO microcapsules were characterized. The encapsulation efficacy and physicochemical attributes of CO were closely associated with the characteristics of the PS carriers. FT-IR analyses confirmed the encapsulation of the essential oil in microcapsule form. PS-based microcapsules possessed a higher thermal stability. During the in vitro simulated digestion and release process, the gastric release of PS-based CO microcapsules was delayed, while the intestinal release was relatively gradual, exhibiting a superior sustained release effect. The final release amount of CO ranged between 82.60 % and 91.18 %.