Polyvinyl alcohol-based materials encapsulating carvacrol obtained by solvent casting and electrospinning

摘要

Carvacrol has been encapsulated in polyvinyl alcohol (PVA) matrices by electrospinning and casting. Aqueous solutions containing 15% PVA and 15% carvacrol with respect to polymer have been used, containing or not Tween 85 at 0.3 g/100 g carvacrol. Electrospun mats exhibited beads and thin fibres which became thinner and interrupted when carvacrol was present and retained up to 83% of this compound. The encapsulation efficiency in the electrospun mats decreased in the presence of surfactant, reaching values similar to those of casting (75-77%). The electrospun, surfactant free material was practically amorphous with 40% of the total carvacrol non-thermally releasable. In contrast, when surfactant was present and in cast material, with 40% crystallinity, the strongly bonded carvacrol ratio decreased. Specific PVA - phenolic hydroxyl interactions played an important role in the degree of carvacrol retention in the matrices, which depended on surfactant's presence and processing method.