PLA bilayer films containing lignin nanoparticles in combination with umbelliferone as active agent

M. IGLESIAS MONTES,; D. PUGLIA; V P CYRAS; L. B. MANFREDI

Buenos Aires

Simposio; XIII Simposio Argentino de Polímeros. SAP 2019,; 2019

The continue demand of semi-prepared natural and fresh food products with high nutritional value have promoted the development of new food packaging systems that improve the shelf-life of packaged foods. The packages must contain, cover and protect the foodstuffs from the external attacks as light irradiation, external contaminations and oxidation induced by the contact with the air. The most important processes of food deterioration are the oxidative ones, which are liable for the modification of flavor, the degradation of vitamins, and the deterioration of foodstuffs such as the browning of meat, fruits and vegetables. In this scenario, antioxidant active polymeric based packages are an interesting strategy to improve the quality and the safety of packaged foods by stopping or reducing the oxidation of different food components, principally, proteins and lipids. Their manufacture is centered on the incorporation of antioxidant compounds into the packages and their further migration to the food (Fabra et al., 2016). Moreover, bio-based and biodegradable polymeric systems are the main preferred materials for this application in order to reduce the amount of wastes in landfills. Unluckily, biodegradable polymers are characterized by some drawbacks when compared with petroleum base matrices, such as lower mechanical performance and poorer barrier properties. In this context, the development of bilayer films represents a valid strategy to modulate the moderate characteristics of biodegradable polymers. Poly(lactic acid) (PLA) is a thermoplastic linear aliphatic polyester, obtained from renewable resources, compostable and biodegradable. PLA is accepted by US Food and Drug Administration (FDA) as a food contact matter, non-toxic or carcinogenetic, easy to process, transparent and economically feasible. Then it is appropriate to be used as short shelf-life packaging. Lignin components provide specific food antioxidant properties and UV stabilization effect (Yang et al., 2016). It has been established that the radical scavenging activity is related to particle size and that the antioxidant effect increase decreasing the dimensions of fillers, i.e. by using lignin nanoparticles (LNP). Moreover, active ingredients such as umbelliferone (UMB), a natural phenolic extract extensively spread in plants of the coumarin family with antioxidant and antimicrobial effects (Luzi et al., 2018), could improve the antioxidant response of polymeric films even in a multilayer approach. The aim of this work is therefore the design and characterization of PLA based bilayer films containing LNP in combination with UMB as active ingredient (AI) for food packaging applications (Iglesias Montes et al., 2019). The effect of the nanoparticles and the AI on the properties of the bilayer systems was studied, emphasizing the determination of antioxidant and light transmission results according to the proposed use of the materials as packaging.