Most of the common edible film-forming materials can be classified as either polysaccharides based (e.g., agar, alginate, carrageenan, cellulose and their derivatives, chitin, chitosan, pectin, and starch) or proteins based (e.g., collagen, gelatin, keratin, whey, casein, zein, wheat gluten, and soy protein ).
![gelatin edge blending gelatin edge blending](https://www.dick-blick.com/items/006/18/00618-slowdri-blend-grp2ww-m.jpg)
Edible films are generally thin layers, which can be consumed, coated on a food or placed as barrier between the food and the surrounding environment to preserve its natural organoleptic properties and to prolong its shelf life. The biopolymers used as raw materials of edible films should be capable of forming a continuous matrix and normally are obtained from renewable and abundant sources. The increase in consumer demand for environmental-friendly food packaging and longer shelf life has encouraged further research into use of natural biopolymer materials such as packaging materials especially edible films. All three factors were significant taken individually and interactions of the three factors were also significant ( or 0.10) except for the interaction between adhesive concentration and sealing temperature. A sealing time of 1 s was used for all samples. The model was statistically significant and an optimum combination of sealing parameters was obtained to be 24.4% adhesive concentration, 0.28 MPa pressure, and 153☌ temperature. The seal was evaluated for seal strength and a quadric regression model to predict seal strength as a function of adhesive concentration, pressure, and temperature during sealing was established.
![gelatin edge blending gelatin edge blending](https://i.pinimg.com/736x/41/87/86/418786a19ff8410cb039809c4e4de3b8.jpg)
The edible film was prepared from blend of three polymers (sodium alginate, sodium carboxymethyl cellulose, and gelatin) based on previous research work.
![gelatin edge blending gelatin edge blending](https://ars.els-cdn.com/content/image/1-s2.0-S1751616117300644-fx1.jpg)
Three important sealing parameters, namely, adhesive concentration, pressure, and temperature during sealing, were investigated to assess sealing performance of the edible film. One of the hurdles in the use of edible packaging for moisture rich foods is its ability to successfully seal the package, which is critical due to the lower strength and elastic characteristics of edible films compared to plastic based films. Edible packaging has been successfully used for packaging of low moisture foods such as wrappers.