Coffee silverskin and starch-rich potato washing slurries as raw materials for elastic, antioxidant, and UV-protective biobased films

•Potato starch and coffee silverskin from food industries are valorised.•Brownish films with enhanced elasticity and stretchability are produced.•Crude coffee silverskin improves the water tolerance of potato starch films.•Potato starch/coffee silverskin films show antioxidant and UV-protective ability.