Edible polyethylene glycol modified chitosan nanoparticles: Separation and controlled release of tea polyphenols from...

Tea polyphenols have potent antioxidant and lipid-regulating properties but suffer from low bioavailability and instability. Here, we present a novel PEG (polyethylene glycol)-modified chitosan nanoparticle system to adsorb and separate tea polyphenols from tea extract. It incorporates a hydrophilic PEG layer to enhance stability and adsorption efficiency compared to traditional chitosan nanoparticles. Under optimized conditions (pH = 5.0, 120 min, 35 °C), PEG-CS NPs with 0.3 % PEG achieved an adsorption capacity of 81.01 mg/g. Kinetic analysis revealed that the adsorption process conforms to the Elovich model (R² = 0.947), and the isotherm data fits the Langmuir model (R² = 0.995), indicating chemisorption and monolayer adsorption. In antioxidant assays, PEG-CS NPs maintained sustained activity compared to free polyphenols, while simulated gastrointestinal tests showed a controlled release profile (10.41 % in gastric juice within 60 min and 90.05 % cumulative release in the intestinal phase). These findings underscore the efficiency of PEG-CS NPs in enriching and protecting tea polyphenols while demonstrating their potential as targeted delivery carriers. Future applications may extend to functional foods and drug delivery systems, where eliminating complex elution steps simplifies processing, reduces polyphenol loss, and enhances bioavailability.