Pectin-encapsulated amorphous naringenin with enhanced aqueous solubility prepared by simple coacervation and precipitation

Abstract

This study presents a sustainable approach for enhancing the solubility and processability of naringenin, a poorly water-soluble bioactive flavonoid, through fruit peel-inspired encapsulation. Amorphous naringenin nanoparticles were first prepared by anti-solvent precipitation using polyvinylpyrrolidone (PVP) as a crystallization inhibitor. Subsequently, ethanol-induced coacervation with pectin, a biopolymer abundant in citrus peel, was employed to encapsulate and recover the nanoparticles under ambient conditions, avoiding energy-intensive drying methods. The process yielded microcapsules with significantly reduced crystallinity, as confirmed by X-ray diffraction, and improved dissolution behavior in both deionized water and simulated intestinal fluid compared to pristine naringenin. High-methoxy pectin demonstrated superior encapsulation efficiency (up to 76%) and produced more compact and spherical microcapsules than low-methoxy pectin, highlighting the influence of pectin structure on encapsulation performance. This simple, low-energy, and scalable technique not only improves the functional properties of naringenin but also valorizes pectin from fruit by-products, providing a sustainable strategy for the development of functional food ingredients.