Biobased active films aimed for food packaging

HERNANDEZ, M.F; MARCOVICH, N.E.; ANSORENA, M.R.

Rio de Janeiro

Conferencia; Fifth international Conference on Natural Polymers and Biomaterials, ICNP 2017 Rio; 2017

The aim of this work was to use wheat gluten (WG) to develop active, edible and suitable films for food packaging. The films were prepared by intensive mixing and compression molding; a thermoplastic process involving high temperature and high pressure. Thyme essential oil (TEO), which has very interesting antioxidant and antimicrobial properties, although intense aromas that could limit the organoleptic acceptability of the final product, was selected as the active ingredient. For this reason, the essential oil was microencapsulated in -cyclodextrins (-CDs) and then incorporated into the film forming mixture. Control films made by TEO added directly to the polymer were also prepared for comparison.The synthesized films were characterized in terms of water vapor permeability, water solubility, color, transparency, mechanical properties, antimicrobial and antioxidant activity. The results indicated that films containing free TEO are less soluble in water and more rigid (higher Young´s modulus) than those made with microencapsulated oil, although the water vapor permeability of the latter is lower. Moreover, active films containing 10 wt% free oil did not present inhibition against gram negative bacteria while 10 wt% encapsulated TEO inhibited both, gram positive and negative bacteria and native microflora of different vegetables and presented enlarged antioxidant properties. In addition, the films containing microencapsulated TEO exhibited antimicrobial effects that last longer. The results of the present study confirm the suitability of using TEO/-CD microcapsules incorporated in wheat gluten films for food packaging applications.