2.2. Preparation of CWP film forming solution
ACWPfilm forming solution, containing 0.8% w/v chitosan and 2.4% w/v lyophilized milk whey (11% WP), was prepared by mixing of chitosan dissolved in 0.1 N HCl and lyophilized milk whey dis- solved in distilled water under continuous stirring. The pH of the chitosan-whey solution was adjusted to pH 5.0 with 0.1 N HCl, and the solution was filter-sterilized through a Sterilcup filtration system (0.45 mm cut off, Millipore, Bedford, MA, USA).