Effects of different kinds of polysaccharides on the properties and inhibition of Monilinia fructicola of the thyme essential oil-chitosan based composite films

Abstract

In order to investigate the controlled release and antifungal effect of thyme essential oil on peach fruit, the four polysaccharides such as xanthan gum, gum tragacanth, arabic gum and pullulan were used to construct the essential oil-chitosan based composite film. The physical and chemical properties of composite film and its inhibition effect on Monilinia fructicola of peach fruit in vitro and in vivo were evaluated. The results showed that thyme essential oil contained some antifungal compounds such as 2-methoxy-3- (2-propenyl)-phenol, D-limonene and thymol. The addition of four polysaccharides decreased the tensile strength and elongation at break of composite film, and caused obvious fluctuation in the peak at 3263, 2884, 1552 and 1025 cm^-1. Particularly, the strong interaction was found between chitosan and arabic gum which improved the antifungal effect of thyme essential oil in vitro. Moreover, the chitosan composite film combined with arabic gum exhibited the best inhibition effect on Monilinia fructicola of peach fruit in vivo regardless of the coating of film solution or film fumigation method. The work showed that chitosan-arabic gum composite film would be a potential application for improving the antifungal effect of essential oil on the preservation of peach fruit.

Keywords:
thyme essential oil; polysaccharide film; Monilinia fructicola; peach fruit