Antioxidant Electrospun Poly(3-hydroxybutyrate--3-hydroxyvalerate) (PHBV) Films Loaded with Resveratrol Solubilized in Deep Eutectic Solvents.

The present study explores the remarkable capabilities of deep eutectic solvents (DES) for enhancing the antioxidant properties of films containing the natural antioxidant resveratrol (Res). A key achievement of this work is the unprecedented solubility of resveratrol400 mg/mLin a highly effective DES composed of choline chloride (ChCl) and ethylene glycol (EG), representing a significant enhancement over previously reported values. For the active and sustainable packaging development purposes, this was coupled with the creation of continuous and nonporous electrospun poly-(3-hydroxybutyrate--3-hydroxyvalerate) (PHBV) biopaper material through electrospinning and subsequent thermal annealing processes, featuring enhanced antioxidant properties. Remarkably, a second achievement of this paper is that electrospun biopapers containing DES-solubilized Res exhibited a 30% improvement in antioxidant activity and material efficiency compared to those containing the same amount of nonsolubilized resveratrol within the polymer. Additionally, characterization was made via wide-angle X-ray diffraction, optical properties, mechanical and barrier testing, demonstrating that the studied DES not only optimized the functional attributes of PHBV biopapers but also maintained their structural integrity and mechanical and barrier performance. Therefore, this study highlights the potential of DES as a potent tool for improving the effectiveness of poorly soluble natural antioxidants, paving the way for the development of innovative solutions in active and sustainable packaging.