Electrospun hybrid TiO2/humic substance PHBV films for active food packaging applications

Sustainable packaging materials can play a key role in minimizing the environmental footprint of packaged food by preserving its quality and avoiding environmental persistence of plastic waste. Waste to wealth approach can cope with these major challenges by providing for bioavailable active compounds from waste residues. To this regard, humic substances (HS), derived from biowaste oxidative processes, exhibit intrinsic antioxidant and antimicrobial features, which can be significantly boosted by molecular combination with an inorganic nanostructured phase. Herein, this approach has been integrated with the electrospinning technology to design composite films made of electrospun biodegradable and bioderived polymers filled with nanostructured hybrid HS based materials. Therefore, electrospun composites made by including hybrid TiO2_HS nanostructures into PHBV matrix were first produced and then converted into homogeneous and continuous films to obtain an active layer which will be part of a multilayer food packaging solution. These were characterized in terms of morphology, thermal, crystallinity, optical, mechanical and barrier properties as well as antimicrobial performance against Staphylococcus aureus and Escherichia coli, two main strains of food pathogens. The results suggested that the combination of hybrid nanomaterials with electrospinning methodology is a promising and sustainable approach to convert biowaste into multifunctional materials for active packaging.