Formulation and Characterization of Zein/Gum Arabic Nanoparticles for the Encapsulation of a Rutin-Rich Extract from Ruta chalepensis

Abstract Rutin, a plant flavonol characterized by a wide range of biological effects, has limited application in foods because of its low water solubility and scarce bioavailability. This work aimed to investigate the encapsulation of a rutin-rich extract (200.6±1.5 mg/g of rutin) from Ruta chalepensis in zein nanoparticles (hydrodynamic diameter of 80-170 nm) prepared by antisolvent precipitation and stabilized by gum arabic (GA). The addition of GA (1:1 mass ratio with zein) significantly reduced the instability phenomena of zein nanoparticles through the deposition of a negatively charged layer. It also contributed to enhancing the encapsulation efficiency of rutin and enabled a more sustained release during simulated digestion, likely because of the formation of hydrogen bonds between zein and GA, in addition to those observed between zein and the extracts. These findings show that zein/GA nanoparticles represent a promising delivery system for natural extracts, fabricated through a facile and versatile process.