Characterisation and evaluation of PLA films containing an extract of Allium spp. to be used in the packaging of ready-to-eat salads under controlled atmospheres

Abstract

New food packaging systems are been developed by food industry. The present work proposes the use of polylactic acid (PLA) containing different percentages of an Allium spp. extract (2%, 5%, and 6.5% Proallium®) to be used in the packaging of ready-to-eat salads. Mechanical and optical properties of PLA films studied did not show remarkable changes when the active substance was incorporated. Additionally, no significant antioxidant activity was observed, although remarkable antimicrobial activity was recorded, mainly in films containing 5% and 6.5% of the Allium spp. extract. Moreover, the antimicrobial effect in vivo was observed in lettuce. All developed films decreased enterobacterial growth in a concentrationdependent manner. Regarding aerobic bacteria, film with the highest concentration of active agent (6.5%) was found to be effective up to 5 days of storage, and even 7 days for moulds. Therefore, the PLAProallium® film could be a promising antimicrobial active material, especially for ready-to-eat salads.