Development of bioactive PVA/Sargassum muticum composites for sustainable packaging applications

The presence of brown Sargassum muticum (Phaeophyceae) along European coastlines provides an abundant biomass source rich in bioactive compounds. In this study, we report the fabrication of a novel composite material based on polyvinyl alcohol (PVA) incorporating an ethanol-soluble extract of S. muticum. Unlike conventional extraction protocols that typically require elevated temperatures, the process was carried out at room temperature, allowing ethanol to selectively solubilize specific molecular fractions naturally present in the alga. The resulting bio-based composite was processed into polymeric films and characterized optically, in chemical composition, and surface properties. The incorporation of the extract into the PVA matrix enables the formation of a material suitable for packaging applications. Since PVA is a recyclable and, in many formulations, biocompatible polymer, integrating marine-derived components provides a pathway toward more sustainable packaging materials with added functional properties originating from the algal extract. This work, therefore, introduces a strategy for valorizing S. muticum while producing an innovative PVA-based composite aimed at recyclable and potentially biocompatible packaging solutions.