Intelligent and active composite films based on furcellaran: Structural characterization, antioxidant and antimicrobial activities

•Furcellaran films with yerba mate/green tea extracts and nanoparticles were prepared, characterised and evaluated.•Tea extracts improved the antioxidant activity of furcellaran films.•The furcellaran films with SeNPs showed excellent antimicrobial activity.•Modification of furcellaran film with ZnONPs and yerba mate extract improved UV barrier properties.•Films with tea extracts have potential to be used as intelligent fish spoilage sensors.