Insights into the in vitro digestion, antioxidant, and antibacterial properties of hawthorn polyphenol nanoparticles

Hawthorn polyphenols (HP) have various physiological functions; however, they are unstable in nature and are easily degraded by environmental changes. In this study, hawthorn polyphenol-chitosan nanoparticles (HPN) were prepared using dynamic ultra-high-pressure microfluidization (DHPM) and ion gelation methods, and their stability, in vitro sustained-release performance, antibacterial performance, intestinal bacterial fermentation characteristics, and cellular antioxidant properties were investigated. HP was successfully loaded into chitosan nanoparticles, with an average particle size of 301.12 nm. HPN exhibited higher thermal stability than unem-bedded HP. Molecular self-assembly dynamics simulations demonstrated the stability of HPN through electro-static, van der Waals force, and hydrogen bond interactions. Intestinal fermentation studies revealed that acetic, propionic, and butyric acids were the main free fatty acids in the intestine and that their contents increased with increasing fermentation time (p < 0.05). Additionally, HPN exhibited strong antibacterial properties, and its antibacterial effect was greater against Gram-positive bacteria (Listeria innocua) than Gram-negative bacteria (Escherichia coli). The cytotoxicity assay showed that HPN prepared using DHPM and ion gelation has high biological safety. Cell antioxidant assays showed that HPN effectively ameliorated oxidative stress induced by H2O2. Overall, the prepared HPN has potential applications in the development of new multifunctional food ingredients and realizing functional factor homeostasis.