All-in-one: Harnessing multifunctional natural polysaccharide spray hydrogel loaded with polyphenol-metal nanoparticles for fruit preservation

Fruit preservation materials play an instrumental role in preventing fruit deterioration and extending shelf life. However, existing fresh-keeping materials often prove inadequate in simultaneously achieving antibacterial properties, maintaining freshness, antioxidant effects, good biocompatibility, and prolonged fruit shelf life. Therefore, we present the first preparation of a natural polysaccharide spray hydrogel (Q/O/Zn hydrogel), loaded with chlorogenic acid‑zinc nanoparticles (CA@ZnNPs), utilizing quaternary ammonium insect chitosan (QECS) and oxidized pullulan (OPUL) for the preservation of perishable fruits. The findings demonstrated that the Q/O/Zn hydrogel was highly effective in inhibiting the proliferation of S. aureus and E. coli, while also exhibiting remarkable scavenging capabilities about ABTS and DPPH radicals. Furthermore, the fruit preservation trials demonstrated that the Q/O/Zn hydrogel markedly reduced fruit respiration rates, decay rates, and weight loss across various temperatures while decreasing the species diversity and abundance of harmful bacteria on fruit surfaces. The Q/O/Zn hydrogel is promising for fruit preservation.