abstract
This paper compares the effect of adding different high barrier nanostructured interlayers with adhesive
properties, made of electrospun whey protein isolate (WPI), pullulan, zein and zein blends with WPI and
pullulan, to a polyhydroxyalkanoates material, specifically, polyhydroxybutyrate-co-valerate with a
valerate content of 3% (PHBV3) in a multilayer form. The attained morphology, thickness and inherent
permeability of the electrospun nanostructures played an important role on oxygen and water barrier
properties of these multilayer systems, since both permeability values were only improved when fibrillar
morphologies (pullulan and/or zein fibres) were obtained. More specifically, oxygen and water vapour
permeability values were improved between 38e48% and 28e35%, respectively, in multilayer systems
prepared by the addition of electrospun zein and/or pullulan nanofibres. However, the electrospun WPI
nanostructures, exhibiting a beaded morphology, did not significantly decrease the water vapour and
oxygen permeability values of the PHBV3-multilayer systems as did zein and pullulan (fibres). These
results add new insight, to other previous studies, into the potential of this processing method for the
development of biodegradable PHBV multilayer systems of significant interest in food packaging
applications.