Influence of food-grade biopolymers on the stability and in vitro release of microencapsulated Tithonia Diversifolia leaf extract

The instability and limited bioavailability of plant-derived bioactive compounds restrict their application in functional foods and in nutraceuticals. This study investigated the influence of food-grade biopolymers on the stability and in vitro release of microencapsulated Tithonia diversifolia leaf extract. Microcapsules were prepared using gum arabic (MGA), maltodextrin (MMD), and chitosan-NaTPP (MCT). The stability, release behavior under simulated gastric (pH 2.2) and intestinal (pH 7.4) conditions, release kinetics, and cytocompatibility were evaluated. All formulations exhibited different release profiles under the tested pH conditions, with lower release at pH 2.2 and higher release at pH 7.4. Release kinetics analysis suggested a predominantly Fickian diffusion mechanism. Among the tested formulations, MGA exhibited favorable antioxidant stability, release characteristics, and cytocompatibility (IC50 = 9112.67 μg/mL). These findings demonstrate that food-grade biopolymer selection significantly influences the stability, release characteristics, and biological compatibility of encapsulated phytochemicals, supporting their potential application as functional food ingredients.