Development and characterization of cassava starch films incorporated with blueberry pomace

This work is focused on the development of renewable and biodegradable films by the valorisation of wastes from food processing industries, with the aim of contributing to the development of more sustainable films. In this context, different contents of blueberry pomace (BP) were incorporated into cassava starch (CS) film forming solutions and the functional properties of the films prepared by solution casting were investigated, specifically, thermal, optical and physicochemical properties. BP-incorporated films showed good barrier properties against light, indicating their beneficial effect to prevent food deterioration caused by UV radiation when these films are used for food packaging applications. These results were related to the presence of aromatic compounds in BP, which can absorb light at wavelengths below 300nm. Furthermore, all films maintained their structural integrity after immersion in water (24h) and the maximum swelling displayed was lower than 300%. Additionally, the release of active compounds from BP into food simulants (after 10days) showed higher migration into the acetic acid medium in comparison with the ethanol medium. Therefore, the incorporation of BP into CS film forming solution resulted in the improvement of film performance, suggesting the potential application of these films as active packaging.