Epigallocatechin-3-gallate stabilizes aqueous curcumin by generating nanoparticles and its application in beverages

In this study, we addressed the limited water solubility of curcumin by utilizing epigallocatechin-3-gallate to form nanoparticles through self-assembly. The resulting particles, ranging from 100 to 150 nm, exhibited a redshift in the UV–visible spectrum, from 425 nm to 435 nm, indicative of potential π-π stacking. Molecular docking experiments supported this finding. Curcumin loaded with epigallocatechin-3-gallate showed exceptional dispersibility in aqueous solutions, with 90.92 % remaining after 60 days. The electrostatic screening effect arises from the charge carried by epigallocatechin-3-gallate on the nanoparticles, leading to enhanced retention of curcumin under different pH, temperature, and ionic strength conditions. Furthermore, epigallocatechin-3-gallate can interact with other hydrophobic polyphenols, improving their dispersibility and stability in aqueous systems. Applying this principle, a palatable beverage was formulated by combining turmeric extract and green tea. The nanoparticles encapsulated with epigallocatechin-3-gallate show potential for improving the applicability of curcumin in aqueous food systems.