Alkynyl silver modified chitosan as a novel antimicrobial coating material for potential food applications

Authors: MEI, LEI - University Of Maryland; ZHANG, FUWU - University Of Maryland; ZHANG, JINGLIN - University Of Maryland; LI, YUAN - University Of Maryland; LIU, YIJING - University Of Maryland; Luo, Yaguang - Sunny; WANG, QIN - University Of Maryland

Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2020
Publication Date: 11/22/2020
Citation: Mei, L., Zhang, F., Zhang, J., Li, Y., Liu, Y., Luo, Y., Wang, Q. 2020. Alkynyl silver modified chitosan as a novel antimicrobial coating material for potential food applications. Carbohydrate Polymers. 254:117416. https://doi.org/10.1016/j.carbpol.2020.117416.
DOI: https://doi.org/10.1016/j.carbpol.2020.117416

Interpretive Summary: Silver-based antimicrobial agents have strong efficacy against a broad range of microorganisms. However, the potential uncontrolled and untimely release of silver ion and the concerns over heavy metal pollution to the environment limit its application in the food industry. To overcome these challenges, a coating material was developed by substituting alkynyl Ag onto chitosan through chemical modifications. The physicochemical property, antimicrobial activity, cytotoxicity, and potential food application of this silver-chitosan coating was further examined. Results demonstrate improved silver stability and controlled release. Findings benefit food industry in developing novel coating materials for improving microbial inactivation, and food quality and safety.

Technical Abstract: Silver (Ag) based antimicrobial agents are known for their strong antimicrobial activity against a broad spectrum of microorganisms without leading to drug resistance. However, most of these agents suffer from uncontrollable release of Ag; some of these agents contain Ag cores can potentially cause heavy metal pollution to the environment due to incomplete degradation of their Ag cores. To overcome these challenges, we developed a novel antimicrobial coating material by substituting alkynyl Ag onto chitosan (Ag-CS) through chemical modifications. The physicochemical property, antimicrobial activity, cytotoxicity, and potential food application of Ag-CS were systematically investigated. It was found that Ag-CS presented a smooth sheet structure, and demonstrated stronger antimicrobial effects than either AgOAc or AgNO3 against both Gram+ and Gram- bacteria strains. Ag-CS also demonstrated a controlled release of Ag for over 5 days. Using shrimp as a model food, Ag-CS coating significantly extended its shelf life. Overall, our results revealed that the novel Ag-CS antimicrobial coating material possesses strong antimicrobial efficacies with a sustained Ag release, and its ability to slow down the spoilage rate of food products indicates its potential for processing preservation applications.