Research On Antibacterial Composited Film With Humidity Sensitivity

Mix the natural plant oils of good antimicrobial properties with water-soluble resin to prepare coating liquid and dispose LDPE film. Then make the moisture sensitive and preservation packaging bags, at the same time study the preservation effect on the fruits.Qualitative and quantitative analysis about the main components of two essential oils by GC-MS, which are oregano and lemon grass. The result is that the main components of the oregano are carvacrol and thymol. The absolute content of those are 0.7962g/ml and 0.02998g/ml. The main component of the lemon grass is citral. The absolute content of that is 0.45786g/ml.By adding different amounts of oregano and lemon grass oil to PVA solution to make coating and adjusting the coating process parameters(pressure between the steel rod with plastic roller, pressure between the rubber roller and the rubber roller, steel roller model), acquire the packaging film of different content of antibacterial ingredients. The properties of air permeability, water vapor permeability and light transmission are tested by the machinery of densometer, cup and transmissometer. The results show that with the increased amount of oil coating, air permeability has improved, water vapor permeability has almost constant and light transmission has decreased. Analysis on the content of volatile oils in the moisture sensitive antibacterial composite film. The result shows that the concentration of PVA and oils and the environment have the great effect on the volatilization in the coating solution by GC-MS. Under the highly humid conditions, with the increasing storage time, the volatile concentration of the essential oils has increased. When in the tenth day, the oils volatilized completely out of the composite film.Antibacterial composite film is made of bags for preservation of cherries and grapes, then overall apparent,the decay rate,weight loss rate,breathing physical hardness,soluble solidsascorbic acid content,titratable acidity of cherries and grapes are tested and analyzed during storage by spectral photometry,optical measurement method and acid-base titration method, the results show that the best protection of HDcherry is composited film coated oregano essential oil concentration 3.75%, oregano and lemon grass compound essential oil concentration 3%,fresh period is extended to the sixth day at room temperature; the best protection of JF grapes is composited film coated lemongrass essential oil concentration 3.5%, fresh period is extended to the eighth day at room temperature,the shelflife both are improved to double compared blank group.