The development of active packaging is a result of the needs of modern times. The concept of active packaging involves its interaction with food through an active compound in or on the surface of the packaging material to improve the shelf-life and quality of food. The goal was to improve the functionality of an inert polypropylene (PP) film with two-layer coatings, with the first layer based on primary or quaternary chitosan and the second layer based on natural extracts, either brown algae (Padina pavonica), juniper needles or blackberry leaves. We prepared films with different combinations of coatings to obtain data on the impact of individual coatings and their effect in a two-layer application. We confirmed the presence of coatings on the films by weighing and by an XPS analysis. We determined the physico-chemical properties of foils, important for food packaging (wettability, oxygen permeability), and tested the antioxidant potential and antimicrobial activity against S. aureus and E. coli. Chitosan and the blackberry leaves and juniper needles extracts improved the antioxidant potential of films, while foils with a layer of algae extract showed a much lower antioxidant potential. Quaternary chitosan and extracts proved excellent antimicrobial activity against S. aureus. Only films with an individual layer of quaternary chitosan proved good antimicrobial activity against E. coli. The presence of both chitosan and extracts is important, as it not only introduces good bioactive properties into the bilayer and is key for the concept of active packaging, but it also improves wettability, i.e. reduces the contact angle, as also oxygen permeability, which are important for the functionality of food packaging.
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