The effect of plasticizers on the functional properties of biodegradable gelatin-based film: A review

Food packaging derived from a petroleum base represents a serious environmental problem. Finding alternative sustainable solutions is a must. Therefore, the current study has focused on the production of biodegradable food packaging from renewable materials, primarily gelatin. The effect of the biomaterials used on functional properties of the films produced needs thorough investigation. Gelatin represents interesting biomaterials for developing biodegradable food packaging, mainly due to their good film forming properties and abundantly in nature. However, the incorporation of gelatin in biodegradable films for food packaging may give some drawback on certain properties of the film such as tensile strength and water vapour permeability. Thus, addition of plasticizers into the film materials improves the functional properties of films by increasing their extensibility, dispensability, flexibility, elasticity, and rigidity. This study aims to review the current findings on how plasticizers impact the functional properties of biodegradable gelatin-based films. Plasticizers incorporation in the films may affect the continuity of the polymer matrix, leading to physical changes, where the films become more flexible and stretchable. Generally, the plasticization effect of plasticizers strengthens the film structure, in which the tensile strength and elongation of the films are improved and water barrier properties are reduced.