A Review on the Effect of Different Plasticizers on the Properties of Whey Protein-Based Films

Over the recent years, many efforts have been conducted towards replacing the fossil oil-based materials with biomaterials as eco-friendly and renewable alternatives due to the importance of attention to the environment. Regarding this, proteins is of great importance to be utilized in many different fields such as food packaging, pharmaceutical and agricultural applications. However, extensive applications of these bio-based materials are still challenged by one or more of their inherent limitations, such as poor process ability, brittleness, poor moisture and gas barrier and poor thermal and physical properties. The incorporation of additives such as plasticizers into the biopolymers is a common practice to modify these limitations. Generally, plasticizers are added to both synthetic and bio-based polymeric materials to impart flexibility, improve toughness, and lower the glass transition temperature. The free volume-induced plasticizer’s addition into polymer matrix could enhance the permeability property. This review is targeted to introduce different plasticizers used in food packaging for thermoplastic processing of whey protein as an excellent oxygen barrier material that also provides suitable mechanical properties.