Active packaging based on PLA and chitosan-caseinate enriched rosemary essential oil coating for fresh minced chicken breast application

Active packaging systems are considered an effective way to prolong the shelf life of fresh food products. This study compared five different biopolymer films for their ability to delay the lipid oxidation of raw chicken meat. New antioxidant poly lactic acid film was prepared by coating the film surface with chitosan or chitosan/caseinate blend enriched with rosemary essential oil at concentration of 1% and 2%. Films were characterized in terms of microstructure, water vapor permeability, mechanical properties, and antioxidant capacity. In vivo study was done using fresh minced chicken meats stored at 4 °C and analysed after 0, 4, 7, 11, 14, 21 days. Results indicated that water vapor transmission rate was reduced by the presence of the coating and assumed the lowest value (1.23 ± 0.03 × 10−4 g m-2 s-1) with coating enriched with 2% of rosemary essential oils. The films showed an antioxidant capacity of maximum 6% equivalent to the antioxidant capacity of 6,25 μg of REO/mL. Results from in vivo test showed that the active films were able to reduce meat oxidation during storage in anaerobic modified atmosphere condition: samples packed with active film showed constant malondialdehyde (MDA) and colour up to 14 days and reduction of heptanal and ethanol concentration compared to samples packed with control film (72 % and 90 % respectively). Overall, this study has demonstrated that PLA films coated with an active coating are a promising delivery method for providing antioxidant effects in packaging for fresh meat products.