**4.2 Edible coatings and films**

Increased use of synthetic packing material poses an environmental threat during its disposal, hence some coating techniques evolved that satisfy both the product shelf life and less threat to nature (**Table 3**). The materials used or coating must full fill some features such as acceptable sensorial characteristics, appropriate barrier properties, good mechanical strength, reasonable microbial, biochemical, and physicochemical stability, safety, low cost, and simple technology for their production [23].

Mostly used coating materials are polysaccharides of starch, proteins, the cellulose that does not pose any harm to human health. Carboxymethylcellulose is one of the materials that gained attention because of its wide applications. The materials used may be extracted from plants such as (corn zein, wheat protein, soy protein) or from animals (casein, whey protein). Pullulan, produced by *Aureobasidium pullulans*, is capable of forming edible films but it is been largely exploited as a coating material, because of its high water solubility. One example of pullulan used as a coating hydrocolloid was for strawberries and kiwifruit [23].


#### **Table 3.**

*Oxygen and carbon dioxide permeabilities of edible films.*
