Inherently acidic films based on chitosan lactate-doped starches and pullulan as carries of nisin: A comparative study of controlled-release and antimicrobial properties

•Inherently acidic (pH ≈ 4.5) chitosan lactate (CHL)-containing films were obtained.•Corn and wheat starch granule residues resulted in rough and opaque films.•Partially soluble starch/CHL carriers showed nisin (NIS)-trapping ability.•100% soluble CHL and pullulan/CHL films ensured fast and complete release of NIS.•Probably due to similar pH, the NIS-added films had similar antibacterial activities.