Study On Preparation And Sustained Release Performance Of Tea Polyphenols Antioxidant Film

In order to guarantee the quality of food and prolong its shelf life,a new type of antioxidant activity food active packaging technology comes into being.In this paper,TP/PVA antioxidant film was prepared,choosing polyvinyl alcohol(PVA)as film-forming substrate,tea polyphenols(TP)as antioxidant,glycerol as plasticizer.Then,single factor experiment was used to study the impact of glycerol content,PVA solution concentration and TP content on the physical and mechanical properties of TP/PVA film and using the response surface analysis method to optimize these parameters.Diatomite,montmorillonite and kaolin were chosen as mineral fillers to fill TP/PVA film and the effect of different mineral fillers and additives on the properties of TP/PVA blend film.The morphology of the TP/PVA blend films was inspected by infrared spectroscopy and scanning electron microscopy.Further,the effect of related factors on the release of TP from TP/PVA blend film was studied by release test.The results are shown as follows:(1)The better film making process was explored by the response surface methodology.The research was shown that the mechanical properties,barrier properties and light transmittance of TP/PVA antioxidant films were the best when the amount of glycerol was 0.4%,the concentration of PVA was 7%and the amount of TP was 1.0%.(2)The barrier and water resistance of TP/PVA film were improved by filling montmorillonite with 2%,which was better,and water vapor transmission rate,oxygen permeability fraction,water absorption and DPPH free radical scavenging ability of the film were reduced by 7.30%?7.10%?9.51%and 8.39%.The results of infrared spectroscopy and scanning electron microscopy(SEM)were shown that the three minerals and PVA had certain interaction,the hydroxyl interaction between them forms hydrogen bonds and the mineral particles were uniformly dispersed in the TP/PVA film.The film structure was uniform and compact and the compatibility was better.(3)The study results about the sustained release performance of TP/PVA antioxidant film were shown that,in 95%ethanol simulating solution,with the different temperature conditions the release rate of antioxidant was different,and the higher temperature,the faster release rate.The TP release rate in TP/PVA film was decreased after adding mineral filler,which the TP/PVA film filled with montmorillonite with 2%was shown the better performance,compared with the original film at 23?,the cumulative release decreased by 12.64%.(4)The release data of montmorillonite(MMT)/TP/PVA blend film at 23 ? was used to simulate the mathematical model,choosing the zero-order model,the first-order model and the Higuchi model to fit the release process of TP,the result showed that Higuchi model had a better fitting result for the release of tea polyphenols,which was indicated that the release behavior of TP was determined by the diffusion effect.