Developing active poly(vinyl alcohol)-based membranes with encapsulated antimicrobial enzymes via electrospinning for food packaging

The present study addresses the immobilization of the GOX enzyme into a conventional polyvinyl alcohol (PVOH) membrane and a multi-layer membrane system (PCL/PVOH/PCL), both synthetized through electrospinning technique. More specifically, the enzyme was encapsulated inside a PVOH hydrophilic membrane, which was in turn protected by two hydrophobic polycaprolactone (PCL) membranes (multilayer system). The manufactured systems were characterized through IR spectroscopy, enzymatic kinetics and mechanical properties. Moreover, the morphology of the fibers composing the membranes was studied by Scanning Electronic Microscopy (SEM) and image analysis. Finally, the enzyme activity of the systems was in-vitro bacterial cultures using E. coli. The results obtained indicate that the addition of the GOX enzyme involves a slight reduction of the mechanical properties (maximum strain at break and maximum stress), which is associated with an increase of the polydispersity of the generated fibers. However, the mats showed antibacterial properties, which were evidenced by the inhibition of E. coli growth. These results indicate that this technique is suitable for the immobilization of enzymes with potential use in the active packaging industry.