Abstract:

The aim of this work was to manufacture edible composite films by extrusion from xanthan gum and locust
bean galactomannan. Plasticizers and Chinese medicinal herbal extracts were added to improve the film flexibility.
The influence of the concentrations of rhubarb and Chinese gall extracts on mechanical properties, water resistance,
light transmittance, and color properties of edible composite films were investigated. The results indicated that with
increasing concentrations of both extracts, the tensile strength (TS) of films increased, whereas the elongation at break
(E), water vapor permeability and light transmittance decreased. Additionally, the films became darker and showed a
higher green value. In conclusion, composite films made from xanthan gum and locust bean galactomannan as well
as Chinese medicinal herbal extracts are edible, green and degradable and may have promising application prospects
in delaying the postharvest senescence and long-distance transportation during storage and extending the shelf life of
vegetables and fruits.

Key words: xanthan gum, locust bean galactomannan, Chinese herbal edible film, mechanical properties, barrier property