Effect of the added polysaccharide on the release of thyme essential oil and structure properties of chitosan based film

In order to evaluate the effects of microbial polysaccharides and plant polysaccharides on the release of essential oil from chitosan-based composite films, the xanthan gum, pullulan, gum tragacanth and arabic gum were used to prepare the chitosan-thyme essential oil composite films. The results showed that the addition of four polysaccharides reduced the tensile strength and swelling degree, but increased the film solubility. The addition of arabic gum and pullulan delayed the release rate of essential oil from composite films in 95 % ethanol, but not in 50 % ethanol and distilled water. The film swelling was inconsistent with the release of essential oil in different food simulants. Chitosan-arabic gum composite films had better antifungal effect on the nectarine by the way of exposure of thymol released from the film. SEM analysis implied that four polysaccharides affected the microstructure of films. The release of essential oil could be regulated by the interaction between polysaccharides.