Barley b-glucan-protein based bioplastic film with enhanced physicochemical properties for packaging

Cereal grains are sustainable sources of polymers that could be used to prepare environmentally friendly
biodegradable materials. Cereal b-glucans are molecules of interest in different fields, including the food
packaging industry. Whilst the grain as raw material is reasonably inexpensive, the extraction and purification
of b-glucans involve lengthy procedures and high cost. This work describes a simple method for
the simultaneous extraction of b-glucan and protein polymers from barley to prepare biodegradable
films. Physical, mechanical, thermal and barrier properties of the films were investigated and compared
with a reference film. This work demonstrates that films with high stiffness, high thermal stability,
decreased water solubility, and reduced water vapour permeability, can be obtained by manipulating the
extraction medium. The results show that such enhanced properties result from the formation of a strong
structural network established through physical and chemical interactions between the protein and bglucan
polymer chains.