EFFECT OF CHITOSAN INCLUSION ON THE PROPERTIES OF XANTHAN GUM-BASED EDIBLE FILMS

Researches in food preservation have evolved into use of edible polysaccharide products and the most utilized polysaccharide is xanthan gum. In this study, xanthan gum and chitosan were used in composite coating material. The composite films were developed by casting using xanthan gum and chitosan. The films were prepared in varying proportion of xanthan gum and chitosan thus; 90:10, 92.5:7.5, 95:5, 97.5:2.5, and 100:0. The films were analyzed for mechanical properties (Young’s modulus, elongation at break, strain at break, load at break, stress at break and energy at break). Using the elongation at break and Young’s modulus as reference variables, films with the following proportion of xanthan-chitosan; 90:10, 95.5:5, 97.5:2.5 were further evaluated for barrier properties (thickness, solubility in water, oxygen permeability and water vapour permeability) and optical properties (opacity and colour parameters). The elongation at break of each composite film increased with decreased young modulus. The xanthan gum-based films brought about changes in thickness, water vapor permeability and solubility of films but did not change significantly (p ≤ 0.05) the oxygen permeability. Furthermore, the produced films had low opacity values and the luminosity values of the films were directly linked to the transparency of the films. The films with the highest L* value had the least ΔE value and highest WI value. The findings showed that the developed composite polysaccharide films could be useful in reducing environmental problems associated with synthetic packaging.