Antioxidant Migration Studies in Chitosan Films Incorporated with Plant Extracts

The aim of this work was to develop an active biopolymer based on chitosan by incorporating natural antioxidants. Five essential oils (ginger, rosemary, sage, tea tree and thyme) and six hydro-alcoholic extracts (from ginger, green and black tea, kenaf leaves, rosemary and sage plants) were tested. Migration assays were carried out to evaluate the films' activity, and total phenolic content and antioxidant activity were monitored in the simulant during storage. Interaction between natural compounds and polymeric matrix was evaluated by FTIR spectroscopy. The diffusion of the phenolic compounds was not detected in the films incorporated with hydro-alcoholic extracts (HAEs), indicating their entrapment in the chitosan. Migration was observed in the films with essential oils (EOs), and biobased films incorporated with ginger, sage or rosemary essential oils, presented the highest diffusion and antioxidant activity in the simulant, highlighting their functionality and potential to be used as food active packaging material.