Physical, antioxidant and antimicrobial properties of chitosan cinnamon leaf oil films as affected by oleic acid

Abstract

The physical, antioxidant and antimicrobial properties of chitosan (CH)-cinnamon leaf essential oil (C) films, containing or not oleic acid (OA), were evaluated. The addition of OA led an increase in surface charge and particle size of the film-forming dispersions. This is in agreement with a greater CH adsorption on the droplets containing OA and the entrapment of C compounds in the non-polar core of the OA molecule associations. OA contributed to a better retention of C in the film during its drying, diminished the changes in colour parameters provoked by C addition and reduced the film transparency. Water vapour permeability of CH films was reduced by OA incorporation while it increased when they contained only C. Every film containing C showed antioxidant and antifungal properties, depending on the C content (the higher the C content, the greater the effect). OA reduced the antifungal effectiveness of C containing films in line with its encapsulating effect on C compounds. All the coatings were effective in extending the shelf-life of cold-stored strawberries, mainly when CH was combined with C at the ratio 1: 0.5.