A new green self-assembly strategy for preparing curcumin-loaded starch nanoparticles based on natural deep eutectic solvent: Development, characterization and stability

At present, the primary solvents in nanocarrier systems for curcumin encounter challenges related to rapid degradation, and biosafety of organic reagents, surfactants and lipids, which are not suitable for food applications. Therefore, this research proposed an eco-friendly method for the first time, using choline chloride-lactic acid deep eutectic solvent as a solvent for curcumin and a self-assembly medium for short-chain amylose to prepare curcumin-loaded starch nanoparticles. This study investigated the interactions between curcumin and short-chain amylose as well as improved stability. Curcumin was successfully loaded into starch nanoparticles as demonstrated by scanning electron microscopy and confocal laser scanning microscopy analyses. The loading capacity of curcumin-loaded starch nanoparticles on curcumin reached up to 7.99 mg/g, with an encapsulation efficiency of 56.18%. 13C nuclear magnetic resonance spectroscopy peaks at 93–107 ppm and Fourier transform-infrared spectroscopy signals at 3386 cm−1 indicated the formation of a non-inclusion complex through hydrogen bond interactions between curcumin and short-chain amylose. While A-type crystalline pattern and weakening ordered crystallization structure were also probed. Additionally, the formation of non-inclusion complex improved the pH stability and photostability of curcumin through physical barrier of starch nanoparticles and the hydrogen bond interaction between curcumin and starch. Overall, this study established a novel and eco-friendly technique for loading and stabilizing curcumin with nanoscale dimensions, offering potential applications in edible packaging and functional foods.