Sunlight-induced antibacterial poly(vinyl alcohol) grafted 3,3,4,4-benzophenone tetracarboxylic dianhydride film for the preservation of Mongolian cheese

Mongolian cheese is a classic grassland specialty in Inner Mongolia. However, there are mildew, fat precipitation, and short shelf life phenomenon. Herein, we refabricated poly(vinyl alcohol) grafted 3,3 ',4,4 '-benzophenone tetracarboxylic dianhydride film (PBF) with antibacterial activity via solvent casting method. The content of the produced reactive oxygen species (ROS)by PBF was measured, and the preservation effect of PBF on Mongolian cheese was discussed. The prepared PBF has high antimicrobial efficiency (>99 %), can be recycled 3 times. Later, we characterized the microbial diversity of cheese by high-throughput DNA sequencing of 16 S rDNA libraries, and a series of quality indexes were determined for cheese. Results showed that PBF can effectively inhibited five pathogenic microorganisms and controlled the total number of bacteria on Mongolian cheese made it shelf stable for 8 days at 25 degree celsius. The PBF was considered a potential packaging film in the protection of Mongolian cheese.