The Study Of Vacuum Coating On Antimicrobial Packaging Film

Ag and TiO₂ were coated on all kinds of polymer films by vacuum coating, and then prepared antimicrobial films and packed fresh beef in order to prolong its' shelf life.The sensory quality and biochemical changes of fresh beef which were packed by the antimicrobial films were discussed. And the changes included pH and TVB-N of beef. The antimicrobial effect of two films was studied. The content of Ag on antimicrobial films was analyzed by AAS. The content of H₂S from beef which packed by antimicrobial films was also analyzed by GC. The article designed indicative antimicrobial films order that the spoilage beef could be displayed. In the end, the physical quality of antimicrobial films was studied including of intensity of tension, tension rate and coefficient of oxygen permeation.The results showed that the pH and TVB-N of beef which were packed by two antimicrobial films decreased with the content of Ag and TiO₂ on films increasing. What's more, the content of H₂S released from the beef had the same change trend. The beef's shelf life was prolonged from one day to three days. Compared with the uncoated films, the intensity of tension of antimicrobial films was increased slightly, but tension rate was unaffected and coefficient of oxygen permeation decreased. The films coated by Ag and TiO₂ had distinct antimicrobial effect. Both the content of Ag above 33 mg/m² and the time of coating TiO₂ above 5 seconds, the microbial inhibitory rate of two films reached 99%. The Ag₂S produced by reaction between Ag and H₂S had indicative function to the beef's spoilage degree.