Preparation and evaluation of antioxidant packaging films made of polylactic acid containing thyme, rosemary, and oregano essential oils

Τhyme, rosemary, and oregano essential oils (EOs) were incorporated into Polylactic acid resin (PLA) at a concentration of 10% (w/w) using the solvent casting method to generate antioxidant packaging films. Pure EOs showed a radical scavenging activity (RSA) ranging between 84.57% and 87.92% at 10,000 mg/L (ppm) using the 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH) method. The antioxidant activity of film methanolic extracts was 4%–6% lower than EOs at the same concentration. A significant reduction (p 0.05) permeation, migration, and percentage elongation at break of film properties. On the contrary, tensile strength, and Young's modulus significantly decreased (p < 0.05) in films containing EOs. Practical applications The ability to prepare active packaging films that inhibit lipid oxidation and assist in shelf life extension of perishable foods is of great concern to the food industry and the research community. The incorporation of thyme, rosemary, and oregano EOs in PLA films resulted in the preparation of active packaging materials, as shown by: (i) the retardation of the lipid oxidation (ii) a considerable increase in the shelf-life of the product. PLA films, enriched with EOs, may serve as alternative solutions to synthetic antioxidants for food preservation.