Influence of liposome encapsulated essential oils on properties of chitosan films

The effect of the encapsulation of eugenol and cinnamon leaf essential oil (CLEO) in lecithin liposomes on the losses of these compounds during the chitosan film formation process by casting was evaluated. Film-forming dispersions and films with eugenol or CLEO (either free or encapsulated) were obtained and characterized. The content of eugenol in active films was quantified by means of solvent extraction and gas chromatograph analysis. The encapsulation of eugenol or CLEO in lecithin liposomes led to the films retaining 40% - 50% of the incorporated eugenol, whereas only 1% - 2% was retained when eugenol was incorporated by direct emulsification. Films with liposomes exhibited a lamellar microstructure which improved film extensibility and increased water vapour barrier capacity with respect to those with free emulsified compounds. Liposomes also modified the optical properties of the films, reducing their gloss, increasing colour saturation and making them redder in colour. The encapsulation of volatile active compounds in liposomes appears to be a good strategy for obtaining antimicrobial films with essential oils. (c) 2016 Society of Chemical Industry