Evaluation of the properties of whey protein films with modifications

Whey protein concentrate (WPC) has been widely studied as a biodegradable bio-based packaging material in the food industry. In this study, different whey protein films were obtained through physical, chemical, enzymatic, and composite modifications. The molecular structure, micro-morphology, mechanical properties, barrier properties, and other characteristics of the films were evaluated. The results illustrated that the thickness of WPC with composite modification increased and the transmittance decreased, but the mechanical properties and barrier properties were more prominent. The WPC film prepared by physical modification combined with transglutaminase has the best film-forming effect, the tensile strength (TS) was 5.45 MPa, the elongation at break (EAB) was 25.19%, the WVP was 5.53 g·mm/m² ·hr·kPa, and the Oxygen permeability (OP) was 1.83 meq/K, and its microstructure was and uniform. In addition, based on the the results of SDS-PAGE and Fourier transform infrared spectroscopy (FTIR), the intermolecular and intramolecular interactions of various modification methods on WPC were studied, thus contributing to analyze the properties of the film. This study provides theoretical basis and technical support for the industrial production of protein-based films.