Sustained antimicrobial polymer film from γ-CD-MOF humidity switch for fruit and vegetable preservation

To address the poor hydrolytic stability of CD-MOF in food applications, CD-MOF loaded with thymol (TCDM) was prepared and filled into a pectin (PEC)/sodium alginate (SA) substrate with the aid of zein to obtain a thymol-CD-MOF/zein-PEC-SA (TCDM/ZPS) polymer film. Characterization revealed that zein-PEC/SA (ZPS) protected TCDM by forming amphiphilic microspheres. TCDM was able to exist stably in the hydrophilic polysaccharide substrate and achieve a long-term slow release over 336 h. Besides, environmental humidity could also be used as a switch for regulating the thymol release rate, which was consistent with the first-order release model (R 2  > 0.99). TCDM and TCDM/ZPS showed excellent antimicrobial effects against E. coli , S. aureus , and B. cinerea , the most common fungi in plant-based foods. The preservation experiment maintained the quality of strawberry and Agaricus bisporus mushroom. This strategy holds the potential to broaden the application scope and enhance the utility of CD-MOF in food preservation.