Development of Bioactive Polymeric Materials by Incorporation of Essential/Vegetal Oils into Biopolymer Matrices

Abstract

Microbial contamination represents an undesirable event in various domains. Bioactive natural compounds possess plenty of health benefits, including antimicrobial, antifungal and antioxidative activity; however, they are chemically unstable and susceptible to oxidative degradation. In this context, encapsulation or immobilization methods play a key role in enhancing efficiency. Therefore, in this paper are presented some results regarding the development of antimicrobial polymeric materials using surface-modification and emulsion-stabilization approaches. Two polymeric substrates, one biodegradable, poly(lactic acid), and one non-biodegradable polyethylene, functionalized by γ-irradiation have been modified with different active compounds in order to obtain bioactive food packaging materials. The bioactive agents (clove essential oil and argan vegetal oil) were incorporated into a biopolymer matrix (chitosan) then immobilized on the surface of the functionalized substrates by a wet-treatment involving carbodiimide chemistry. The resulted materials were physico-chemically characterized in order to evaluate the molecular interactions between the natural bioactive compounds and polymeric matrix, the stability of the immobilized surface layer, and their barrier properties. Antimicrobial and antioxidant activities were also evaluated. Moreover, the surface biofunctionalized polymeric substrates were tested as potential packaging materials for cheese preservation. The obtained materials have demonstrated improved barrier properties, good antioxidant and antimicrobial properties, which lead to a delay of the tested food spoilage.