Characterization of edible films from whey proteins treated with heat, ultrasounds and/or transglutaminase. Application in cheese slices packaging

•Whey protein film properties were modified by ultrasound treatment.•Ultrasounds produced slightly less water vapor permeable films than heating.•Ultrasounds increased film tensile and puncture strengths compared to untreated films.•Transglutaminase addition did not modify tensile and puncture strengths of films.•Heat treated films can be suitable as separation material in cheese slices packaging.