In this paper, oxidized xanthan gum with different aldehyde
content is successfully prepared by periodate oxidization. X-ray
diffraction measurements and atomic force microscopy images
demonstrate that degradation is concomitant with the oxidization
process, leading to the decrease in crystallinity and the structure
changes. Blended with xanthan gum or crosslinked with oxidized
xanthan gum, glycerol-plasticized gelatin edible films are prepared
using casting techniques. The optical properties studies show that
all films are very transparent and have excellent barrier properties
against UV light. Moreover, xanthan gum can drastically reduce the
total soluble matter, moisture content and water vapor permeability
and greatly improve the mechanical properties and thermal
stabilities of gelatin films, resulting from the interactions and
entanglement between both biopolymers. Compared to xanthan
gum, with the increase of oxidization level, oxidized xanthan gum
can further improve the water barrier properties, mechanical
properties and thermal stabilities of gelatin films. However, the
excessive degradation of oxidized xanthan gum will reduce the
mechanical properties and thermal stability of films.