Zein/chitosan nanocomplexes loaded with polyphenols from Polygonatum cyrtonema Hua improve Pickering emulsion stability and β-carotene protection

• Zein/Chitosan/ Polygonatum cyrtonema polyphenol nanoparticles were prepared. • The nanoparticles significantly enhanced the stability of P. cyrtonema polyphenols. • Pickering emulsions stabilized by ZCP-PCPP nanoparticles exhibited excellent lipid oxidation stability. • The addition of ZCP-PCPP improved the resistance of β-carotene in emulsions against UV light and temperature. • This work contributes to the new methods of polyphenol protection and delivery systems. This study successfully developed a ternary ZCP-PCPP nanocomposite using zein (ZN), chitosan (CS), and the polyphenols extracted from Polygonatum cyrtonema Hua (PCPP) to stabilize Pickering emulsions. The optimal ZN-CS was 2:1, which resulted in the ZCP-PCPP nanocomposite with the strongest encapsulation ability for PCPP, uniform particle size, and strong structural stability. Infrared spectroscopy, fluorescence spectroscopy, and X-ray diffraction confirmed that ZN, CS, and PCPP interacted mainly through hydrogen bonding and hydrophobic forces. Stability analyses demonstrated that ZCP-PCPP markedly enhanced the physical stability and oxidative resistance of the emulsions. Furthermore, ZCP-PCPP nanoparticles at 3–5% (w/v) effectively protected β-carotene against thermal and ultraviolet degradation. These findings highlight that combining natural polymers with bioactive polyphenols provides an efficient strategy for producing stable Pickering emulsions with strong antioxidant protection potential.