Features and performance of edible films, obtained from whey protein isolate formulated with antimicrobial compounds

► Antimicrobial efficacy of additives to whey-protein based edible films was tested. ► Effects of said additives upon mechanical and optical properties were assessed. ► Chitooligosaccharide (COS) was strongest against Gram-negative bacteria. ► Lactic acid was strongest against Gram-positive bacteria. ► COS produced the highest change in optical properties.