Preparation and Properties of Whey Protein Concentrate and Egg White Protein Composite Film

In this study, whey protein concentrate (WPC) and egg white protein (EWP) were used as film forming substrates and 5 U/g protein transglutaminase (TG) was added to prepare WPC/EWP composite film. The effects of the mass ratio of WPC and EWP, pH of film-forming solutions and glycerin content on the properties of WPC/EWP composite film were investigated. Result showed that, when the mass ratio of WPC/EWP was 1:3, the pH of the film-forming solutions was 8, and the glycerol content was 35%. The results of electron microscope showed that the structure of composite film was compact without porosity. The infrared results showed that WPC and EWP had good compatibility. The water vapor permeability of WPC/EWP composite film was 2.08×10⁻¹⁰ g·s⁻¹m⁻¹Pa⁻¹, the transmittance was 73.90%, the tensile strength was 1.60 MPa, and the elongation at break was 151.96%. WPC, EWP and glycerol had good fusion at pH8, which could significantly (P<0.05) improve the mechanical properties of WPC/EWP composite film.