Effects of nisin concentration on properties of gelatin film‐forming solutions and their films

Summary The addition of nisin into a gelatin matrix can change properties of the film. The aim of this work was to develop gelatin‐based films containing different nisin concentrations in order to study their influence on the film's antimicrobial and physical properties and their rheological properties as a film‐forming solution (FFS). The FFS was characterised by rheological assays, and the gelatin‐based active films were characterised and assessed by the effects of nisin concentrations on their various properties, including antimicrobial activity. Nisin's concentration affected not only its viscoelastic properties of FFS but also its film solubility in water, film surface roughness and light barrier. The addition of nisin also slightly modified the water contact angle and the mechanical properties of the gelatin films. Finally, the films demonstrated activity against Staphylococcus aureus and Listeria monocytogenes at concentrations above 56 mg of nisin g −1 of gelatin.