Co-assembled quercetin-proanthocyanidin nanoparticles for improved stability and flavor properties

Quercetin (QUE), a flavonoid with strong antioxidant activities, faces limitations in application due to poor stability, low bioavailability, and pronounced bitterness. Studies have shown that proanthocyanidins (PCs) can synergistically improve the stability and solubility of QUE via molecular interactions. Therefore, this study developed food-derived co-assembled nanoparticles of QUE and PCs (QUE/PCs@NPs) to improve stability, cellular uptake and sensory properties. The results showed that QUE/PCs@NPs had a spherical morphology with an average particle size of 207.43 nm, and possessed high loading capacity and drug encapsulation efficiency. These nanoparticles exhibited good hydrophilicity and remained stable under elevated temperature, ultraviolet radiation, and simulated in vitro digestion. They also showed significant radical scavenging activity against DPPH and ABTS radicals. In vitro cellular studies revealed that QUE/PCs@NPs effectively suppressed H₂O₂-induced reactive oxygen species generation, demonstrated favorable biocompatibility and were efficiently absorbed by cells. Moreover, the assembled nanostructures effectively masked the bitterness of QUE, thereby improving its sensory acceptability. This study provides a feasible strategy to enhance the efficient utilization and sensory acceptability of food bioactive components by applying co-assembled delivery systems.