**5.2 Colour property**

Colour property is mostly used for selecting proper food packaging material [51]. Chitosan has its natural colour; due to this, chitosan edible film has higher greenness and yellowness and has lower lightness than commercial films [166]. Due to the presence of polyphenol in extract of chitosan-gelatin, the composite film became yellow [167]. The colour of the developed edible film can change the overall appearance of the food inside the packaging films. The edible film not only improves sensory quality but also affects the food quality due to that comes in contact with outer light.

Therefore, the colour property requires proper and careful design to avoid this and for higher consumer acceptance [155].
