Aqueous assembly of AgNPs with camellia seed cake polyphenols and its application as a postharvest anti-Penicillium digitatum agent via increasing reactive oxygen species generation

In this study, we developed a method for synthesizing silver nanoparticles (AgNPs) using aqueous assembly assay and anchoring them with camellia seed cake polyphenols (CPs). Zeta potential analysis demonstrated a higher binding affinity of CP-AgNPs to Penicillium digitatum , which could be attributed to the interaction between the hydroxyl group of CP-AgNPs and the polysaccharide present on the fungal cell wall. Compared to AgNPs, the CP-AgNPs outperformed conventional AgNPs in antifungal activity against P. digitatum . The mechanism underlying this antimicrobial effect involves raising the level of oxidative stress by regulating the expression levels of oxidative stress response genes. In addition, CP-AgNPs/CS showed highly effective in reducing citrus decay levels during chamber storage. In conclusion, the use of CPs as anchoring agent in the in-situ aqueous assembly of CP-AgNPs improved their biocompatibility and antimicrobial properties. CP-AgNPs hold great promise for applications in fruit preservation, especially citrus preservation.