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.