Research into cheese by-product makes packaging greener
13 June 2013
Plastic films are used for packaging a wide range of products, offering protection against humidity and potential contaminants. Over time, however, these films let in air, diminishing the properties of the packed products.
While multilayer films combining several plastics are often used to improve protection, most of this packaging cannot be recycled. The researchers behind the EU-funded WHEYLAYER project found a cheese-based biodegradable alternative to conventional multilayer films.
The project team developed a novel packaging material based on whey, a liquid by-product obtained from the production of cheese. The whey is used as a bio-coating – a biodegradable film – for the plastic, offering additional protection while also being recyclable. Tests ran on the Oxygen Transmission Rate (OTR) of the packaging showed that a layer of whey improved the protection level 30-fold compared to conventional plastic films.
The WHEYLAYER project convincingly researched and developed a biopolymer-coating based on whey protein for plastic films able to replace currently used expensive synthetic oxygen barrier reaching OTR, Q100 of 1cm3/m2d bar at 23ºC and 50% RH and Water Vapour Transmission Rate (WVTR, Q100) of 2 g/m²d. The WHEYLAYER-based multilayer films materials are easily recyclable, as opposed to their conventional counterparts.
The LCA showed significant reduction of the environmental impact of the resulting packaging and preliminary evaluation showed that it fulfilled food safety regulations. A patent application was filled regarding the coating process and a WHEYLAYER prototype application machine was built to reach semi-industrial production speed while keeping satisfactory barrier properties.
What makes whey such an interesting material for packaging is that it contains 6.5 grams of ‘protein’ per litre. “Protein molecules are very long and during the drying process they form a structural barrier that is impermeable to oxygen,” said Elodie Bugnicourt, Ecomaterials group leader at IRIS, the research company that co-ordinated the WHEYLAYER project from Barcelona. The Irish partner involved in the project is Dunreidy Engineering in Kilkenny, which provides mechanical and electrical services to the pharmaceutical, biotech, chemical, food and drinks industries.
In packaging applications, the whey product is placed between two layers of plastic – either synthetic or bio-based – thus preserving the flexibility and mechanical strength of the packaging material. As it is much less permeable to oxygen, the whey product provides additional protection against humidity and oxidation, the chemical reaction resulting from the interaction between the wrapped product and air that effectively speeds up ripening and rot.
Europe produces more than 45 million tonnes of whey every year, but 45 percent of it is discarded. Additionally, the plastic based on whey is easily recyclable because the whey product can be ‘washed’ off from the plastic layers by treating it with special enzymes (protease and alcalase), the biological catalysts that help it decompose.
For Europe’s packaging industry, such a recyclable product is important because they have to comply with waste legislation. “Many packaging companies are trying to turn to greener solutions, which makes this product attractive,” said Bugnicourt. Also, the reuse of an existing waste product lowers the carbon footprint.
On the one hand, the increasing amount of green consumers around the world as well as the need to comply with the related legislative pressure has led to market demand for environmentally friendly packaging materials that still meet the need of sensitive food as well as pharmaceutical and cosmetic products. On the other hand, whey can be highly polluting if not properly handled due to its high organic content and 50% of the 50 million tons of whey produced annually in Europe is still unprocessed.
Since WHEYLAYER exceeds the barrier properties of existing biopolymers and due to the demand for recyclable packaging, the market opportunities for WHEYLAYER appear huge as a potential substitute for currently used expensive synthetic oxygen barrier layers such as EVOH used in multilayer packaging.
KEY PACKAGING INNOVATION
The use of the WHEYLAYER barrier biopolymers will be a key innovation in the packaging sector and also result on a very positive impact on the environment as it solves multiple challenges: finding new commercial use of currently discarded cheese by-product, replacing petroleum-based plastics with natural bioplastic while safeguarding the performance and enhancing the recyclability of multilayer film, thus adding huge value for the European packaging industries and their end users especially in the food, cosmetics and pharmaceutical sectors.
In such context, the WHEYLAYER project has received a lot of interest from the packaging industry and its end-users, as the whey protein-coating offers good oxygen barrier properties and can be removed enzymatically, thus the resulting multilayer films presents a greatly improved recyclability.
“We’ve finished the research and development and now we have to get the technology successfully onto the market,” Bugincourt continued, adding that the project consortium has now patented the technology. “There’s an early-stage business strategy and it addresses plans for different sectors and different applications,” she explained. She expects that some of the flexible packaging products could reach the market in the coming years.
The WHEYLAYER project team included 14 industrial and academic partners from Spain, Hungary, Slovenia, Italy, Germany and Ireland, and was co-ordinated by PIMEC, the SME association of Catalonia that represents over 100,000 Spanish companies. The project ran from November 2008 to October 2011 and received an EU grant of €2.8 million.
WHEYLAYER 2, a follow-up project, started in August 2012 within the Demonstration Activity programme. Also funded by the EU, it will focus on up-scaling the results obtained in the WHEYLAYER project, to prove their industrialisation potential and lead to their commercialisation. It will target not only packaging producer and food packer SMEs, but also other, larger businesses seeking more sustainable wrapping methods, including pharmaceutical and cosmetic companies.
WHEYLAYER 2 will focus on final packaging items such as films but also trays, blisters, tubes and cans, and additional packaging functionalities such as convertibility, printability and UV barrier. It will be evaluated as packaging solution for food, cosmetics and pharmaceuticals.
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