As part of the project, the whey proteins are being developed to replace currently used synthetic oxygen barrier layers, without compromising the oxygen or moisture barrier performance of conventional plastic films, whilst increasing their recyclability.
The European Commission’s Seventh Framework Programme under ‘Research for SME Associations’ is funding the project, which officially began in November 2008.
According to the WheyLayer project team, recent academic studies have revealed that whey, the milk protein by-product of cheese production acts as a good moisture-barrier film with acceptable mechanical integrity.
Also, the use of whey coating on plastic films enables the recyclability and reuse of the plastic layer by removing the whey protein chemically or enzymatically.
Preliminary tests on the oxygen permeation properties of whey-protein-coated plastic films carried out to date have revealed that whey protein isolate or concentrate coating solutions displayed excellent oxygen barrier properties, the team claims.
Moreover, common synthetic polyolefin films such as PE and PP block moisture, but have to coated or laminated with synthetic polymers such as EVOH (Ethylene Vinyl Alcohol Polymer) and PVDC (Polyvinylidene chloride) to provide the barrier.
The resulting polymeric structures, whilst effective in minimising oxygen, water vapour, and odour permeation, are characterised by their poor reuse because of the difficulties in separating each layer for its individual recycling.
On the environmental impact of the whey protein coating, the team commented that the use of the cheese by-product could be a commercial use of currently discarded whey.
It could also replace harmful petroleum-based plastics with a natural by-product and meet growing consumer environmental concerns.