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Final Report Summary - WHEYLAYER (Whey protein-coated plastic films to replace expensive polymers and increase recyclability)

The WHEYLAYER project developed a biopolymer-coating based on pure whey protein isolates (WPI) for plastic films able to replace currently used expensive synthetic oxygen barrier layers used in food packaging such as ethylene vinyl alcohol copolymers (EVOH). Indeed WHEYLAYER reached excellent oxygen transmission rate (OTR, Q100) down to ranges of 1 cm3/m2 d bar at 23 ºC and 50 % relative humidity (RH) but also interesting humidity barrier with water vapour transmission rate (WVTR, Q100) down to ranges of 2 g/m2 d (Q100 refers to the barrier properties normalised to a layer of 100 microns thickness). Such values out perform any existing biopolymer.

The developed enzymatic removal of the WHEYLAYER coating within two hours is easily integrable in the plastic recycling plants to allow multilayer films to become recyclable by separating the other combines layers. The performed life cycle assessment (LCA) at research stage showed that the WHEYLAYER material and process allow massive reduction of the resulting packaging environmental impact (by a factor up to four) especially thanks to the advantage of recycling WHEYLAYER-based materials as opposed to incinerating those containing EVOH but also due to used feedstock.

WHEYLAYER-based films were also validated for storing various foodstuffs (sausage, cheese and fresh pasta). Results showed that the shelf life was maintained even when using simpler multilayer films structures and certain sensory attributes were even better for cheese than when it is stored in conventional films. Preliminary tests also showed that WHEYLAYER fulfilled food safety regulations in terms of migration and emission of volatile compounds.

Lastly and in keeping with the process developed at pilot scale that led to a patent application, a WHEYLAYER prototype application machine was built and tested. It allowed reaching semi-industrial production speed (up to 20 m per minutes) while keeping satisfactory material barrier properties.
% Project context and objectives:

The WHEYLAYER project is included in a context whereby packaging market is demanding innovative and green technologies.

In addition, high requirements are put on food packaging in terms of barriers against light, moisture, water vapour and gases for a packaging material are specific to the type of food to be packed in order to guarantee a quality product throughout its shelf life. Protection against oxygen is a key factor in prolonging the shelf life of a product for as long as possible. The appropriate packing atmosphere is needed to avoid colour or taste deviation, oxidation of grease, formation of micro-organisms or damaging of nutrients.

To achieve these requirements expensive multilayer co-extruded or laminated plastic films are widely used in the packaging industry whereby EVOH are often used to obtain a sufficient oxygen barrier.

The plastic recycling process generally consists of the preliminary separation of the different types of polymers, the shredding of the plastic items, the washing of the resulting flakes and their re-compounding and processing into new, lower demanding applications.

However, while the combination of various layers is required for good food preservation, the recyclability of those multilayer packaging are compromised, as mono-materials of high purity are needed for reprocessing.

Furthermore, most packaging materials are synthetic plastics derived from fossil sources and currently available bioplastics do not meet the key requirements of food packaging especially in terms of barrier properties.

Thus research into sustainable packaging materials that maintain the performance of their composite structures has been recently intensified, for example in the WHEYLAYER project which targeted at developing a whey protein-coating for plastic films able to replace currently used expensive synthetic oxygen-barrier layers such as EVOH used in multilayer packaging. It solves multiple environmental challenges: finding new commercial use of currently discarded cheese by-product, replacing pertroleum-based plastics with natural bioplastics while safeguarding the performances and enhancing the recyclability of multilayer films, thus adding huge value for the European packaging and food industries.

Indeed, whey is a by-product of cheese manufacturing that contains approximately 7 % dry matter (d.m.). In general the d.m. includes 13 % proteins, 75 % lactose, 8 % minerals, approximately 3 % organic acids and less than 1 % fat. In general these whey proteins are used as additives in the agro-food industry but 40 % of the 50 million tonnes of whey produced annually in Europe is still unprocessed. Whey protein can be separated and purified from the liquid whey using a membrane filtration process followed by spray drying to obtain either whey protein concentrate (protein concentration 65 to 80 % in d.m.), or WPI (protein concentrations over 90 % in d.m.).

Therefore, the overall aim of the WHEYLAYER project is to develop a new barrier biopolymer based on whey proteins and its process. The subsequent objectives to reach this target are described hereafter.

First of all, the needs and specifications of the packaging industry were defined to drive the formulation of the product e.g. to fulfil OTR Q100 lower than 2 cm3/m2 d bar at 23 ºC, 50 % rH and WVTR Q100 lower than 20 g/m2 d (23 ºC, 85 % to 0 % rH). Formulations were developed through the screening and optimisation of number of whey proteins and natural additives such as plasticisers.

Furthermore, a cost effective and efficient application technique of the whey protein coating (including substrate pretreatment by corona to promote sufficient adhesion, WHEYLAYER coating and drying) on different substrates such as polyethylene terephthalate (PET) and polyethylene (PE) and polylactide acid (PLA) was developed first at the lab and pilot scale which was patented.

The functionality of the WHEYLAYER formulations was tuned by incorporating antioxidants such as ascorbic acid or natural antimicrobials such as lysozyme. The best combination of active agents and their sufficient concentration were tested in terms of the effect of such active packaging on the shelf life of different food stuffs.

Different formats of packaging solutions were derived from the WHEYLAYER coated films at laboratory level such as foil for wrapping, bags and blisters. The mechanical, oxygen and aroma barriers formed by these new packaging was tested. The WHEYLAYER material offered oxygen permeability and moisture barrier characteristics with acceptable mechanical integrity, approaching that of the EVOH polymer at low to intermediate relative humidity conditions. The nutritional, sensory, quality and microbial preservation of different selected foodstuffs was tested comparing WHEYLAYER-based packaging solutions to conventional ones. A study of the risk assessment and impact of WHEYLAYER on overall food safety was done showing no risk of the use of the new material in food contact by e.g. performing migration studies.

The coating formulation were also tested and optimised in terms of recyclability through enzyme-supported separation of the whey protein coating and the polymer substrates to demonstrate that the coating film can be washed off the polymer layer, which can then be recycled. Enzymatic separation techniques were optimised bearing in mind the requisites for industrial plastics recycling operations.

In addition, the biodegradability, compostability and toxicity of the newly developed packages when based on biodegradable substrates in combination with WHEYLAYER coating was investigated.

Furthermore, a LCA for the developed WHEYLAYER materials was made in comparison with commercially available products. While formulating the new material, concern was also given to the cost of selected ingredients to guarantee the future exploitation of the WHEYLAYER material by keeping it of sufficiently low cost to ensure its uptake by the food packaging sector. The developed material cost is in the range of EUR 10 per kg which is in the range of EVOH. Recommendations for future improvements in this area have been outlined for future improvements.

The process for the application of the WHEYLAYER coating was transferred at industrial scale to facilitate the take up and use of the results by industry. Therefore an industrial prototype was installed at the installations of one of the small and medium sized enterprise (SME) partners whereby it has been tested and validated to demonstrate its performance and features both within the consortium and beyond to a large number of industry stakeholders from the packaging sector.

The overriding goal of this project is to ensure that the resulting pre-competitive WHEYLAYER prototype material and process fulfils the set requirements to ensure its further development post-project into a fully industrial system that is taken to market, where its beneficial ecological impact will be felt at European level.

Project results:

The WHEYLAYER results consist of new coatings and new processes to obtain these materials keeping with the needs of industry for a new barrier bio-polymer in the food packaging sector.

The WHEYLAYER formulation is targeted at offering two main types of functional layers i.e. barrier layer and active layer. Each layer formulation being tuneable to meet both structural and functional requirements for their respective applications depending on type of food stuffs packed, its level of barrier requirements, the applicable legislations, etc.

The WHEYLAYER process comprises several successive stages. First of all, the whey is transformed into WPI, the obtained protein is then modified as needed and formulated thanks to the mixing of the necessary additives. The WHEYLAYER formulation is then coated on the substrate which then goes through lamination and eventually post-processes to obtain the packaging items to pack the selected goods before any required post-operation. The packed goods are then commercialised and at the end of the life of the packaging item, it is collected and recycled.

Each stage requires an adaptation for the new material and the generation of intermediary formulations, which could generate new business opportunities along the supply and value chains. The specific formulations and parameters are valuable know-how that are treated as trade secret and cannot be reported in details in this public report.

The anticipated exploitable results generated in the project are highly diverse including the five aspects that are summarised hereafter in general terms (note that each one is defined in greater detail in the related deliverables of the project, some of them confidential).

1. Process parameters for preparing the WPI usable in WHEYLAYER including the isolation and modification of the proteins
The process for transforming sweet and sour whey into WPI was developed using membrane technology and derived WPIs were obtained with high protein purity, nativity, at defined pH and bivalent ions level. They exhibited good processing properties resulting in outstanding film forming properties.

2. Formulation of the WHEYLAYER barrier coating
The addition of plasticisers has been demonstrated as mandatory in order to obtain coatings suitable to be used in multilayer films, i.e. to overcome the intrinsic brittleness initially observed for protein-based coatings. The formulation of the WHEYLAYER material is determined by the following parameters: d.m. content; WPI nature (and eventually further chemical or enzymatic modification of the proteins, the pH, minerals / salts addition), content; plasticiser nature and content; further additives may be needed to enhance functional properties.

3. Formulation of the WHEYLAYER active layer
Active layers incorporating either antimicrobials or antioxidants were developed in order to extend the shelf life of the packed foodstuffs. The active formulations are defined by the following parameters: dilution medium and application mode (coating or spraying); nature of the active ingredients (depending on legislation for the packed foodstuff); the required concentration of active ingredients depends on the foodstuff. Various antimicrobials and antioxidants were tested and validated for cheese and fresh pasta packaging.

4. Process parameters for applying the WHEYLAYER and eventual modifications to the equipment so it can handle the WHEYLAYER
Based on the tests at the lab and pilot scale and further scale up tests, engraved roller coaters were suitable for the application of the WHEYLAYER formulation on the carrier film. After application, the WHEYLAYER coating needs to be stabilised before the film can be winded. This curing / drying stage is done using a combination of infrared (IR) lamps and convective fans at a determined airflow and temperature. Both the amount of water in the formulation and the design of the drier used have been optimised in order to have an eco-efficient process following the patent filled during the project. It was furthermore showed that a preliminary corona treatment is needed in order to generate sufficient adhesion between the carrier film and the WHEYLAYER coating.

5. Process for recycling the multilayer plastic (changes to remove the WHEYLAYER)
The recycling process consists of the shredding of the films, the washing and the separation of the plastic flakes before each plastic can be recycled independently. The washing stage of the recycling process needs to be tuned to allow the hydrolysis of the WHEYLAYER. The modifications include the addition of an enzymatic detergent, the slight warming up of water or extended washing duration.

Potential impact:

Advantages of the WHEYLAYER technology compared to packaging available today:

The expected advantages of the WHEYLAYER packaging solutions compared to those that are available today on the market are summarised here.

In terms of technical properties WHEYLAYER achieved much superior barrier properties compared to other bioplastics. WHEYLAYER coating can substitute other synthetic barrier layers, such as EVOH, while providing recyclability to multilayer films.

In terms of use in the plastic / packaging industry, the conversion of the WHEYLAYER coating process is easily integrable at plastic films / packaging producers (with licensing to the WHEYLAYER patent) and further improvements will allow reaching real industrial production speeds. A range of packaging solutions can be derived from WHEYLAYER-coated films using post-processes available in the industry such as lamination, thermoforming, thermosealing, welding. Therefore WHEYLAYER will be available in tubes, laminated cans, tray, films, blister formats.

In terms of environmental advantages, the holistic 'cradle to cradle' environmental approach followed throughout the WHEYLAYER material and process development provided a new packaging solution, with increased sustainability, to environmentally aware producers and consumers. WHEYLAYER is based on bio-sourced materials obtained as a reuse of a by-product from the agro-food industry so not in food competition and resulting in lowering waste generation. WHEYLAYER allows recyclability of multilayer packaging thereby responding to a legislative request. WHEYLAYER is obtained through an eco-efficiency process. WHEYLAYER-based laminates have a much a lower environmental impact compared to those based on EVOH, with key savings in terms of raw materials and end of life.

In terms of market and economic advantages WHEYLAYER is expected to be cost competitive with other barrier plastics such as EVOH (EUR 8 to 13 per kg) in a short term. As the price of fossil fuel based plastics will continue increasing and as the production volume of WPI and WHEYLAYER will increase, the WHEYLAYER price could become even more advantageous in the midterm while still keeping the same technical performances and with unique environmental advantages. WHEYLAYER could be a preferred packaging material for food products and especially dairy products while reusing its by-product and thus closing the loop. This is expected to be a keep marketing message. WHEYLAYER can be extended to the packaging of other sensitive goods such as cosmetics and pharmaceutical products.

Potential impacts of the project results:

As both packaging producers and consuming industries alike continue to make valiant strives to attain environmental sustainability in light of a growing realisation that climate protection and conservation of resources are necessary pre-requisites to enable stable development of society and the economy, bioplastics are becoming a topic of global economic interest. Over the past five years packaging suppliers have been introducing various forms of biodegradable plastics made from a variety of plants based on projections that consumers and recycling regulations will drive demand for environmentally-friendly packaging. Some companies are predicting that the market will grow by about 20 % a year. Therefore WHEYLAYER offers huge potential to achieve beneficial impacts in terms of business opportunities and competitiveness, environmental protection and social enhancement.

There are three main potential markets for application of WHEYLAYER results:

1. Supplier of raw, processed material and equipment:
The European Union (EU) dairy industry as suppliers of whey for the manufacture of WHEYLAYER will benefit from increased income and a secure long-term disposal route for their whey, which is essential for avoiding production constraints and environmental risk. A major by-product of the dairy industry is whey. About 90 % of the milk used for cheese making ends up as whey and in the past the cost of disposing of whey has driven some of the smaller cheese makers out of business. This increased profitability and productivity will lead to economic growth and job creation within the cheese making industry at European level, as demand for whey increases, having a very positive impact on rural sustainability. Suppliers of bio-packaging materials will benefit from increased sales and turnover by being able to supply the European plastics processing and packaging industries with a new whey material. Suppliers of equipment and machinery to industry will benefit from increased sales and turnover via increased activity in the development and modification of equipment and machinery for the processing of the WHEYLAYER.

2. Plastics processing and packaging industries:
The EU plastics processing and packaging industries will experience multiple benefits by the uptake of the above results. Reduction in the amount of scrap produced overall in the plastic industry given that the use of the WHEYLAYER material will increase the recyclability of their processed plastics, enabling to recover valuable and expensive polymer materials, thus greatly boosting the profitability and performance. Consumers are more and more demanding to use sustainable materials with good recycling ability, so they will see this important advantage in the WHEYLAYER material. Increased sales and turnover by being better equipped to meet with increasing market and legislative pressures to improve the eco-friendliness of their packaging products and respond to growing concerns among more knowledgeable and responsible European consumers, who are increasingly taking into consideration the impacts of their purchasing decisions on such critical issues as the environment and climate change, while at the same time not wanting to make any trade-offs in terms of product quality or safety. To this end, manufacturers of packaging and plastics processors incorporating the novel WHEYLAYER can expect to boost their sales and market share, by using packaging materials that are suitable for use in a growing number of applications where packaging needs to be recycled after its use and by not causing recycling issues in any EU country and being acceptable internationally, especially as consumer concerns. Highly positive influence on public acceptance of plastic industry because bio-based materials (WHEYLAYER coating itself as well as coating of bio-based substrate films) will be used, materials with low environmental impact will be promoted, possibility of recycling will be widely disseminated using specific logo. Plastic industry will regain good reputation that was partly lost in the recent years due to low material recycling and waste problems on land (still a lot of plastics is being landfilled) and sea (marine litter).

3. End users of plastic packaging:
The European food industry and packaging users beyond will gain a significant competitive advantage by being using packaging that is not only more recyclable than conventional synthetic packaging, but which also offers suitable performance for the preservation of their products' quality, freshness and safety. All products will have good barrier properties and will be therefore suitable for packing sensitive products that demand packaging with specific properties. This will enable them to meet with increasingly exigent consumer, market and legislative demands, thus providing them with a powerful marketing weapon which will differentiate them from their competitors and assist them in boosting the sales and turnover. WHEYLAYER products will be verified for use as a packaging material in food, cosmetic and pharmaceutical industry. The plastic materials, packaging and manufacturing process markets will be broadened thanks to the introduction of novel products. Plastic industry will be provided with a new barrier material. The need for valuable raw materials will be decreased with consequent better use of resources in that WHEYLAYER will be produced by waste by-products, pose environmental impact via their disposal and do not involve food competition.

In addition to the economical impact within and beyond the consortium, WHEYLAYER addresses number of environmental and societal issues in Europe but indeed worldwide concerns. Given the free movement of goods within Europe, it is fundamental to provide solutions to common consumers asking for more sustainable and responsible products. In short, the following impacts could be derived by the WHEYLAYER material: as previously mentioned, the share of recycled plastics and bio-plastics will increase- this is important given that plastic that ends up in landfill (not to mention the plastic containers that end up in our seas and oceans) has a life measured in hundreds to thousands of years. The uptake of solutions such as WHEYLAYER used as a bioplastic material in packaging applications would help to redress the problem of growing and persistent volumes of plastic litter. The recyclability of packaging will be enhanced and this could heighten standards and practices in that area.

The image of plastics, especially in food packaging, will improve. Indeed WHEYLAYER will be based on a by-product from the agro-food sector and therefore not competing with food supply and which is still available in excess.

Scrap levels will be reduced throughout the involved stakeholder supply and value chain (from dairy to plastic and packaging industries), reducing environmental impact and increasing margin.

Further positive environmental benefits through the reduction of non-renewable / fossil resources depletion and a reduction of energy consumption and related carbon dioxide (CO2) emissions (as the price of oil continues to increase) contribute to the replacement of a significant portion of the over 250 million tonnes of petroleum-based plastics used worldwide today.

There are number of legislative incentives for recyclable films and packaging solutions at the European level that will be answered by the WHEYLAYER technology. Within the packaging sector, the recycling legislation is expected to be a key driving force for WHEYLAYER introduction. Indeed the European Directive on packaging and packaging waste (94/62/CE and 2004/12/CE) are targeted at promoting design for recycling, developing system for the return and/or collection of used packaging and prevention, with a recycling objectives of 22.5 % for plastics in 2008. The total volume of available post-consumer plastic waste arose in 2008 to about 24.6 million tons. In terms of plastic waste generation packaging with a share of approximately 63 % is by far the largest plastics waste fraction in the European countries. Furthermore the European Directive on waste (2008/98/CE) establish a waste hierarchy and waste management policy. As such when developing new products, end-of-life aspects - especially recycling ones - should be an integral part of the design process and this should be a key driver for selecting WHEYLAYER-based materials.

Various related actions have been performed during the course of the WHEYLAYER project. Those included ensuring that the recycling process for multilayer films would be easily integrable into recycling plants, while recyclers would be educated regarding the suitable handling of the new material that would be identified by a specific logo. Such actions will ensure that when the volume of the WHEYLAYER products increase after its market launch it is indeed recycled and specified by packaging designers at the source to meet their need of recyclable packaging.

Another environmental benefit that WHEYLAYER offers is the local supply of barrier polymers and solution to whey disposal. The new offer for local production and supply of barrier polymers is a really interesting evolution for the packaging industry in Europe since this market is under a quasi-monopole from Japan (producing over 80 % of EVOH) and whereby polyvinylidene chloride (PVDC), another important barrier polymer, is banned in several European countries.

In addition, WHEYLAYER could offer a local (European) solution to whey disposal. Indeed, the disposal of whey produced during cheese production has always been a major environmental problem due to its high organic content. Proper disposal is therefore essential given that untreated whey can cause serious water pollution. Over the past two decades or so technological advances have made it economically possible to recover soluble proteins from cheese whey. However, despite its nutritional value, data from the International Whey Conference 2008 shows that 40 % of total whey production in Europe continues to be discarded.

Main dissemination and exploitation activities:

As previously discussed, the foreground generated by the WHEYLAYER project is broad and covers the whole supply and value chain and gives rise to potential exploitation opportunities for each member of the consortium. Each partner has expressed its intentions and wishes for the exploitation strategy. In addition, it allowed a great deal of dissemination activities to be carried out.

The current status of the protection and exploitation strategy for the WHEYLAYER foreground within the consortium can be summarised as follows:

1. A patent related to the WHEYLAYER process was submitted with eight owners among the industrial partners.
2. SME associations (SME-AGs) are researching which of their members are interested in using the results of the project so they could get preferential access for them in correlation with guidelines from exploitation agreement.
3. The supply and value chain partners of the consortium are getting ready to route the results of the project to the market especially the companies forming the patent exploitation committee as described after. Mlang is looking at possible investments to upgrade their whey process to obtain suitable WPI for WHEYLAYER plastic. This could also involve the guidance and support from DUN. TUBA is looking for potential investments in new production lines, tooling and new staff and looking for appropriate partners in cosmetics and pharmaceutical industry for joint further research and development. Serviplast is making further trials with their customers to validate the use of WHEYLAYER in pharmaceutical application and possible investments to later produce the WHEYLAYER material by themselves.
4. A recognisable brand name and specific logo to build awareness around the new material with its improved recyclability potential has been registered by the companies forming the patent exploitation committee.

A really successful dissemination strategy has been carried out during the WHEYLAYER project maximising the exploitability of the material and demonstrating its potential to fill the gap for environmentally friendly packaging materials for sensitive food to reach the requirements of the increasing amount of 'green' consumers.

Over the course of the project, a total of 102 dissemination activities have been carried out including participation in conferences, trade fairs, publication of articles in the general and industrial press and on the web as well as interviews, the details of each can be found in the list annexed as well as in the plan for the use and dissemination of foreground (PUDF). In fact, the project has received a lot of interest from the packaging industry and its end users (e.g. during the participation of the whole consortium in the trade fair Interpack), all really keen in up-taking the new technology or using the new material to pack their products. In addition, the WHEYLAYER project has been recognised by the European Community (EC) among their star projects with high potential (Eunonews innovation programme 'Greener plastics').

Project website:

Contact details for general enquiries:
Mr Robert Carroll
PIMEC Patronal de la Petita i Mijana Empresa de Catalunya, Spain

For technical issues:
Dr Ing. Elodie Bugnicourt
IRIS Innovació i Recerca Industrial i Sostenible, Spain

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