Properties enhancement of packaging materials based on gelatin

Abstract

The main disadvantages of plastic materials are that they do not readily break down in the environment and cause harmful effects. For a specific use, biodegradable and/or edible films have been produced to totally replace some typical polymeric packaging materials. Protein and polysaccharides biopolymers have film-forming properties that are useful for food packaging. Gelatin is an example of a protein that has the ability to form a film, has strong functional qualities, and can be used as an exterior barrier to prevent drying. Gelatin has adverse effects on food packaging application, especially mechanical properties and water vapor permeability. The effect of the incorporation of plasticizers in gelatin films is reviewed and presented. The plasticizer can improve the extensibility, dispensability, flexibility, elasticity, and rigidity of biopolymers and biopolymers composites. The plasticizers reviewed are glycerol, sorbitol, lignin, root essential oils, bergamot oil, lemongrass oil, sucrose, oleic acid, malic acid, and citric acid, and others. These plasticizers have strengthened the film structure by continuity of polymer matrix where the gelatin films become more stretchable and also flexible. This study also discussed the effect of plasticizers on other properties of gelatin film such as water vapor permeability (WVP), thermal properties, water-solubility, moisture content, oxygen permeability, light transmission, and transparency.