Antioxidant activity of PLA/PCL films loaded with thymol and/or carvacrol using scCO2 for active food packaging

Abstract

Present study was aimed to produce biodegradable films with antioxidant activity for active food packaging. Films of poly(lactic acid) (PLA) with 5 wt% of poly(ε-caprolactone) (PCL), denoted as PLA-5, were loaded with thymol, carvacrol and their mixture using supercritical CO2 at 40 °C and 10 MPa for 5 h, with 27.53, 21.18, and 21.49 % of loading achieved, respectively. Morphological, structural and mechanical properties of the obtained PLA-5 films were analyzed. The highest total polyphenol content and the best antioxidant activity as well as good storage stability, acceptable physical properties and the lowest release rate (44.51 mg/L released after 6 weeks) were observed for PLA-5 film loaded with thymol and carvacrol mixture. Mixture of thymol and carvacrol loaded into PLA-5 film showed synergy and low percentage of migration into distilled water, revealing great potential for application as a food packaging material with aim to decrease requirements for amount of the active ingredients.