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Development of sustainable protein-based paper and paperboard coating systems to increase the recyclability of food and beverage packaging materials

Final Report Summary - BIO-BOARD (Development of sustainable protein-based paper and paperboard coating systems to increase the recyclability of food and beverage packaging materials)

Executive Summary:
The overall goal of the project is to replace existing plastic coatings in multilayer paper and board-based packaging and enhance their recyclability. A coating system based on renewable raw materials derived from agrofood waste (based on whey proteins from cheese production and potato pulp from starch production) and its technological application by extrusion and lamination with paper or board to produce packaging materials for both solid and liquid food products were developed.
The first achieved target of the project focused on defining the technological needs of paper and board packaging converters in different food and beverage application sectors in a close cooperation of the industry and research partners.
In parallel, the lab scale trials stated. They firstly focused on the development of processes for extracting proteins from potato fruit juice (PFJ) and pulp. For this a number of process variations and combinations were evaluated and optimized. The most promising technology was selected and transferred into pilot scale. At the same time activities on protein modification started resulting in the development of a protein-based formulation suitable for extrusion processing. Further building on previous results, the extrudability of the proteins was achieved by applying a bio-based plasticiser as well as reactive additives. This initial formulation was continuously optimized throughout the project. This covered trials with potato proteins, the screening for alternative plasticisers and additional reactive additives as well as the application of blend partners such as potato pulp fibres and conventional polymers biodegradable or not. This resulted in the final BIO-BOARD formulation used for scale-up of the extrusion process whereby further adjustments were also made.
Extruded protein based layers were laminated with other materials such as paper, cardboard, aluminium foil and/or plastic films using adhesives to obtain multilayer packaging structures. The different laminates were used to carry out in-depth material characterisations and to recycling tests as well as packaging trials with different solid and liquid foods.
For characterisation of the laminates, resp. the stand-alone films, packaging relevant properties such as oxygen and water vapour permeability and mechanical properties were determined. Furthermore migration studies to ensure compliance with food contact legislation were carried out. Based on these results, the most appropriate laminate structures were selected for packaging trials. In these trials storage tests with four model foods were conducted. After storage time the food products were characterized regarding changes in their chemical and physical properties as well as their microbial load. Furthermore a sensorial evaluation was conducted. These tests revealed that BIO-BOARD material is well suited for packing most of the food products used: in comparison to the references used, most properties were similar of even better with BIO-BOARD material. However the sensorial properties of cocoa were affected by the novel material, and the non-aseptic conditions of milk packing at lab scale prevented a long term good microbiological state also in the reference material.
In addition, the BIO-BOARD material was also evaluated regarding its environmental performance. For this, recycling tests were carried out and an LCA was conducted. In comparison to conventional laminates, the novel structures have an improved recyclability and a suitable recycling process was identified to recover each fraction in the laminates. The significant potential for reduced environmental impact was also pointed out when reducing the amount of material used as well as when using a bio-sourced blend partner.
The public website of the project informs the target audiences on the basics of the technology, latest news and the progress of the project. The project partners also took part in number of events including 4 demonstration activities organized as part of the project, as well as a TV coverage by Euronews.

Project Context and Objectives:
About 7 million tons of coated paper, paperboard and cardboard are currently manufactured annually worldwide. The standard coating material is petrochemical based polyethylene (PE). Typical laminate packaging contains about 20 mass percent of this material. Increased political, legislative and consumer pressure to reduce the dependency on fossil fuel based plastics, but also to produce recyclable solutions, poses a major challenge for packaging producers to seek alternative materials that do not harm the environment in their manufacture and end of life, are based on a sustainable resource, and offer similar performance to their conventional plastic counterparts. To this end, there is a great need to provide producers of coated paper, paperboard and cardboard manufacturers with a bio-based material that will enable them to substitute much of the currently used PE coating without compromising the humidity barrier properties of the resulting packaging materials and overcoming the current challenge to the recycling of such packaging.
The overall goal of the project is to replace existing plastic coatings in multilayer paper and board-based packaging and enhance their recyclability. A coating system based on renewable raw materials derived from agrofood waste (based on whey proteins from cheese production and potato pulp from starch production) and its technological application by extrusion and lamination with paper or board to produce packaging materials for both solid and liquid food products were developed.
To this end, the specific objectives can be summarised as follows:
1. To analyse the needs and specifications of European coated paper, paperboard and cardboard manufacturers and end-users to define the specifications for the BIO-BOARD system.
2. To develop the process for extracting suitable proteins and pulp from potato waste to complement whey protein to be used in the bio-based coating for paper and board.
3. To develop bio-coating and bio-composite formulations additivating and modifying the previous raw materials as required, and to carry out process development work in order to extrude and laminate the formulation.
4. To characterise the thermo-mechanical and barrier properties, as well as convertibility properties of the resulting coated board. To characterise the recyclability of the new packaging material and to study its biodegradability, compostability and environmental impact by a Life Cycle Assessment in comparison with commercially available packaging.
5. To study the nutritional, sensory and microbial quality preservation of food and beverages using BIO-BOARD packaging as well as its compliance with legislation.
6. To scale-up the production process at near-industrial and to validate the resulting materials before carrying out a series of demonstration activities to show the benefits of the new technology.
Regarding the development of the protein based formulation a significant progress versus the state-of-the art was achieved. This is especially concerning the challenges related with protein extrusion and thus processability to obtain a coating and finally a laminate. In BIO-BOARD a number of paper and cardboard based laminates were produced and tested. These were structures with and without aluminium or other plastic layers included. Several of these laminates provided good oxygen and water vapour barrier properties as well as suitable mechanical characteristics. The protein based coating showed a good adhesive strength both with paper and cardboard and resulting laminates complied with food contact legislation, but also allowed a suitable conservation of beverages such as fruit juice and food products such as dehydrated soup.
As a part of BIO-BOARD project, the novel bio-based coating was also evaluated regarding recyclability and its environmental impact. In fact, due to the proven easy separation of the layers the need of mechanical shearing during the pulping process is reduced. This might very likely result in a better quality of the recycled fibres. Furthermore a life cycle analysis (LCA) of the new BIO-BOARD packaging solution characterized environmental impact showing a good potential for optimization versus conventional counterparts.
Finally the BIO-BOARD production, especially flat film extrusion, was upscaled in semi-industrial environment and resulting material was characterized pointing out required improvements. In particular, further research work is needed to allow an industrial production at equivalent thickness and speed to synthetic coatings conventionally used, as well as in terms of reaching a neutral smell.

Project Results:
Different elements of foreground from the project have been defined which will be described in details subsequently below:
1. Raw materials suitable for the BioBoard application
2. Coating formulations
3. Coating production process set up
4. Derived laminates suitable for different applications
5. Environmental aspects (specific recycling or composting process and data, data of LCA...)

o Raw materials suitable for the BioBoard application
In BIO-BOARD project, three different raw materials all of them by-products from food industry were used. These were in particular whey, potato fruit juice and potato pulp.
Whey is a by-product of cheese production with a dry matter content of 7%. This dry matter consists of 13% proteins, 75% lactose, 8% minerals, 3% organic acids and 1% fat. Whey protein, as used in the project, can be separated and purified by membrane filtration process followed by spray drying and is widely commercially available at different grades of purity ranging from Whey Protein Concentrate (WPC, protein concentration 65-80 % in dry matter d.m.) to Whey Protein Isolate (WPI, protein concentrations over 90% in d.m.). The specific raw material used in the BIO-BOARD coating formulation was commercial WPI: BiPro from Davisco Foods International (Le Sueur) (d.m. 93.52 %; protein 98.74 % of d.m.; fat = 0.21 % of d.m.; minerals = 1.94 % of d.m.; Lactose = 0.02 % of d.m. with 22.8 % of α-lactalbumin and 67.7 % of β-lactoglobulin).
Potato fruit juice and potato pulp are both residues obtained during starch production. Potato fruit juice (PFJ) is a liquid by-product with a dry matter content of 5.6%. As analysed in the project, the dry matter mainly consists of protein (52.3%) and inorganics (15.7%). In contrast potato pulp is a solid residue with a dry matter content of 14.8%. It mainly consists of crude fibres (21.1%) and starch (15.2%). Furthermore it contains 8.1% proteins as well as 4.1% inorganics.
Novel applications for food packaging for whey and potato proteins as well as pulp fibres in composite formulations were developed within the project. Indeed, as opposed to whey protein which is widely used as food supplement, purified potato proteins have limited commercial availability. Therefore significant efforts have been invested aiming at the definition of suitable process for extracting proteins from potato fruit juice resp. pulp purification.
The application of hydrolytic enzyme activities as well as a drying procedure was evaluated for pulp purification. For protein extraction of potato proteins from fruit juice, different processes and process combinations were applied. These included filtration, precipitation, centrifugation, adsorption etc.
The protein products obtained by applying the different separation technologies were characterized regarding yield, purity and their techno-functional properties, in particular film forming ability, solubility and color. Based on these results further potential for process optimization was elaborated and implemented in lab scale.
For process evaluation, the above mentioned figures as well as cost estimation were taken into account. Based on the results, the most suitable processing for potato fruit juice and pulp was selected and transferred into pilot scale.

o Coating formulations
A key objective of BIO-BOARD project was the development of suitable formulations for extrusion processing. As proteins lack the required thermoplastic properties and would inherently cross-link in the extruder, a modification procedure had to be established as a pretreatment step. For this, different strategies were evaluated.
Several processes for protein modification have been evaluated in BIO-BOARD project. These included chemical derivatisation in aqueous and organic media, an enzymatic modification procedure as well as the application of reactive additives. The protein products obtained from these different treatments have been evaluated regarding their relevant properties such as film forming ability, thermoplastic behavior etc. Based on the results of this characterization, the different modification methods were adjusted. These process variations carried out included the use of enzyme combinations, the utilization of different additive types and concentrations as well as the application of different molecules and molecule concentrations for chemical derivatisation. As an outcome of this work, the most suitable parameters in terms of modification procedure, reaction partners and reactants concentration was selected for the further work carried out in BIO-BOARD.
Although the application of a pretreatment of the proteins by a modification procedure resulted in extrudability of the material, it was not sufficient to achieve the desired processing and product properties. Therefore a further improvement of the protein based formulation was necessary. Hence intense work on optimizing the formulation in terms of extrudability as well as an improved flexibility was carried out. This work mainly focused on the application of different additives in BIO-BOARD formulation. For this, several chemicals were screened regarding their relevant properties such as their plasticizing effect. This screening did not only focus on the selection of the most suitable substances but also on the definition of the best concentration for their application. Bio-based plasticizers, lipids, fibers as well as other biopolymers were evaluated. Relevant aspects such as bio-sourcing and/or biodegradability as well as food contact legislation of the additives as well as end of life options of the product were taken into account during all stages of coating formulation to maximise the post-project exploitation potential of the results by the industrial partners.
The difficulty in extruding proteins provided opportunities for the RTDs to develop novel modification strategies (e.g. to obtain suitable thermoplastic properties of the proteins, tailored preliminary modification, reactive extrusion, etc. were combined) and the resulting coating formulations selected in the BIO-BOARD project is kept trade secret.
As a result of combining protein modification and tailored additives, a material suitable for extrusion processing became available. This formulation could be processed by single and twin screw extruders repeatedly and converted into stand-alone films applicable for lamination with other packaging substrates (e.g. paper, cardboard) into multilayer structures.

o Coating application process set up
There are number of parameters that are variable in terms of obtaining the BioBoard coating, and as much as possible, the aim was to be able to substitute the currently converted PE by BioBoard just adjusting the process without large modification of extruding equipment. For each of the stages (compounding, film extrusion, lamination) of the process, parameters regarding the suitable machines type and parameters were defined at pilot scale.
In the first lab scale compounding step, additives were incorporated to form a thermoplastic whey protein based granulate, which provides the starting material for the second compounding step leading to pellets at pilot scale. During this step, the pre-dried first formulations were blended with different amounts of thermoplastic biopolymers, pelletized and compounded again with different potato pulp ratios and pelletized again. Films were extruded at pilot scale from the pre-dried pellets. Different multilayer structures were produced in pilot scale using a lacquering and laminating plant at FRAUNHOFER. Corona-discharge-treatment was performed when necessary followed by wet chemical application of adhesives, drying, lamination in the lamination unit and rewinding. This process was repeated in order to create the different multilayer films containing the BioBoard films and PE layers and Paper or Board. All combinations were produced with or without aluminum foil to produce multilayer for the different intended applications.
Prototype pellets and films were also produced at semi-industrial scale and the process could be optimized in 1-step in terms of compounding as a key optimization in that stage followed by a large scale film extrusion. Upscale lamination and pouch production were also tried but lead to the identification of new challenges and the definition of number of required improvements before validating the industrial feasibility.

o Derived laminates suitable for different applications
Number of laminates structures were derived from BioBoard. These are for instance laminates with paper or cardboard, with aluminum or without and with an additional PE layer or without. The nature and number of layers were varied depending on required properties such as barrier, tightness to liquids and sealing.
For each type of laminates, a case study of application in terms of food/beverage storage was tested in order to demonstrate the wide potential of the prototype materials developed in the project. For this, four different model food were used. These were cocoa powder, instant tomato soup, pasteurized orange juice and UHT milk.
For a complete evaluation of the properties of the novel bio-coating, studies on its barrier and mechanical properties were complemented by qualitative studies on nutritional, sensory and microbial quality preservation, as well on the compliance of the new materials with regulatory aspects. This included tests on the packaging material (coating thickness, mechanical strength (adhesion, delamination), sealability/sealing strength, heat resistance, O2 barrier, water vapour barrier, light barrier, water resistance, grease barrier), on the packed food (sensorial, chemical and microbial evaluation over storage time) and on food-packaging interaction in term of migration studies. The evaluation of suitability of the BIO-BOARD laminates developed at lab scale as packaging materials for food contact demonstrated no significant change in the rate of grease permeation and water absorptiveness properties vs. conventional paper- and board-based materials.
In order to evaluate whether BIO-BOARD material is in accordance with European food contact legislation, in particular Directive EC 10/2011, migration test were carried out. These tests revealed that for all laminates tested, migration was far below the maximum level allowed of 10 mg/dm2. Therefore BIO-BOARD laminates showed compliance with the overall limit of migration of substances from the new materials to food according to European legislation.
For a further evaluation of the BIO-BOARD material, storage tests with four model foods (cocoa, instant soup, orange juice and milk) were conducted. During storage physico-chemical quality parameters were monitored. These were in particular pH, solubility, dispersibility, bulk density and dry matter and color for the dry food products. For orange juice quality parameters were browning, pH-value, titratable acidity, cloud loss, ascorbic acid content and dry matter whereas for milk pH, color, titratable acidity, dry matter and protein content were monitored. Furthermore a microbial assessment was conducted repeatedly with all four model foods. The different quality parameters monitored were in general not affected by the use of BIO-BOARD vs. reference material and quality changes were in most cases similar to the reference materials.
From the microbiological point of view, cocoa powder, tomato soup and orange juice samples packaged with BIO-BOARD showed equally good results than samples packaged with conventional laminates. Only UHT milk packed in BIO-BOARD laminates showed a higher microbial content than reference samples, probably due to a poor sealability of the sachet.
To complement microbial and physico-chemical assessment of BIO-BOARD laminates, sensory evaluations of the four model foods were carried out three times during storage tests. The first evaluation was at the beginning, the second in the middle of storage (6 weeks) and a third after storage was completed (12 weeks). Tests revealed that storage in BIO-BOARD laminates altered the aroma of cocoa powder. On the other hand, sensory acceptability of orange juice or UHT milk packaged in BIO-BOARD laminates was equally valued as samples packaged in reference materials. Specifically, in the case of the former, BIO-BOARD packaged samples obtained better results on appearance, odour and overall acceptability at final time of storage.
All data considered, this project showed the suitability of BIO-BOARD packaging laminates developed at pilot scale (containing a biopolymer layer based on whey proteins) for food packaging as an alternative approach to conventional paper and board-based packaging for preserving and extending the shelf life of both solid (soup) and liquid (orange juice) food products. It was not possible to conclude in case of milk due to difficulties to ensure aseptic conditions for lab scale packing. Further research is although needed especially to reach a neutral smell and sufficiently low thickness to allow forming packaging as with reference material.

o Specific recycling process, compostability, data of LCA...
Depending on the structure (eg. presence of aluminum or not), different end of life scenario (material recycling vs. composting mainly) could be respectively envisaged. The current recycling processes for cartons was mapped to define improvements that could be achieved thanks to the easier separation of the BioBoard laminates. In terms of paper based laminates, if allowed by the overall structure, a composting ability is seen as a major improvement as many of those can only be valorized energetically, if not land filled, currently.
In BIO-BOARD of end-of-waste criteria for waste paper and thus the technical requirements hat have to be fulfilled in order allow recycling were defined. For assessing recyclability initially an enzymatic treatment of the BIO-BOARD material and different lamininates with and without aluminum was carried out. These tests revealed that a separation of the fractions PE (incl. aluminum), BIO-BOARD material (BB51) and fibers was feasible. The required duration of treatment was reduced by mechanical pre-treatment of the laminates and stirring of the enzymatic solution during treatment. However this process, although successful from a scientific point of few, had the disadvantage of requiring enzymes, a still rather costly catalyst. Therefore alternative methods were investigated. In this context the treatment with warm water proved to be the most successful strategy. By stirring grinded laminates in moderately heated water for a few hours a complete separation of all four layers fibres, PE, aluminum and BIO-BOARD material was achieved. A recovery of the different pure fraction was done by density separation thus proving full recyclability of the BIO-BORAD laminates.
In addition to recycling studies, the biodegradability resp. compostability of BIO-BOARD laminates was assessed. This study was based on the EU standard as defined in BS EN 13432and thus taking criteria such as biodegradability, degradation kinetics as well as quality of the degradation products into account. Composting tests were conducted using a model soil and complete disintegration of the samples was monitored during composting process. A germination test determined the absence of toxic compounds derived from disintegrated BIO-BOARD material. Therefore the BIO-BOARD layer is compostable also when associated only with paper.
In order to determine the environmental impact of materials developed in BIOBOARD a Life Cycle Assessment (LCA) from cradle to grave was conducted. In this LCA, the BIO-BOARD laminates were compared to the conventional multilayer structures following ISO standards (ISO 14040, 14044). It was calculated that the production of BIO-BOARD material is less favorable in terms of environmental impact mainly due to the utilization of synthetic blend partners with although the prospect to become bio-sourced in the future. Regarding the application of BIO-BOARD material in multilayer structures, the environmental impact was also determined to be higher than the currently used conventional structures using PE. This is strongly related to the thickness of BIO-BOARD material in the laminates which was around 200µm, while PE layers usually have a thickness of 30-50µm. Furthermore it must be considered that when a new material is industrially developed most of the time the impact of its production are considerably worse than those of products on the market whose production has been optimised, thus the benefits from the use of BIO-BOARD materials have margin of improvements. The LCA pointed out the required areas of improvements and was also performed in a future scenario showing that after reaching a thickness closer to the current range of PE and using a bio-sourced blend partner, BIO-BOARD would have a much lower environmental impact than currently used fossil-fuel derived coatings.

Potential Impact:
The BIO-BOARD project was developing a bio-based material and its application process to allow substituting currently used plastic coatings for paper and board (mainly PE, but also PVDC, EVOH...) with improved functionality and significant environmental assets. The final results of the project includes know-how exploitable by the industrial partners in terms of: Raw materials suitable for the BIO-BOARD application; Coating formulations; Coating application process set up; Derived laminates suitable for different applications; Environmental aspects.
There are numerous socio-economic impacts that will be derived from the results of the BIO-BOARD research project beyond the consortium in Europe and beyond.
As previously mentioned the project contributes with a solution to the environmental problems originating from the disposal of by-products from cheese production and potato processing. Moreover the use of materials from renewable resources residues of agrofood industry such as potato and whey protein is of significant value for the material processing industry. Thus the bio-based carbon content in packaging is in agreement with the objectives of Horizon 2020. EC is promoting the use of biobased carbon in materials by deducting the biological/biobased carbon contained in bio -based products in the calculation of the total CO2 equivalent emissions of the products aligned with CO2 cutting objectives under the Kyoto Protocol.
Of particular relevance to the uptake of the BIO-BOARD project results is the recent Lead Market Initiative for Bio-based Products completed in 2011. Indeed, it encourages green public procurement favoring renewable, biological raw materials to substitute products based on other raw materials by introducing requirements for environmental sustainability in tender specifications. It also encompasses non-food new bio-based products and materials such as bio-based-plastics. In comparison to conventional materials, reduced environmental impact and improved recyclability for BIO-BOARD laminates were determined as part of the project. However other sustainability aspects should be considered as well. For a food packaging material this is above all, the protection of the food and thus the protection of resources and a contribution to food security. In addition, when 925 million people go hungry in the world each day, and with the world population expected to reach 9.1 billion by 2050, it is absolutely imperative that research moves us away from the use of food competing resources as is the case when valorizing food by-products.
The project can further contribute in terms of enlarging the basis of materials for packaging, industry and decreasing the need for valuable non-biobased raw materials with better use of resources. Furthermore, in light of the contribution of the different industries covering the supply and value chain and represented in the project to the economy, BIO-BOARD will contribute to raise their competitiveness leading to impacts for the European economy, growth and jobs as well as sustainability at European level and beyond. Packaging is one of the key growing markets for plastics and consumes over 70% of the bioplastics in Europe. Food packages represent 60% of the total packaging market. When BIO-BOARD will be price competitive, its position is promising in the very large market, especially since the global bioplastics market grows at a rate of 20-30 % per year, jumping from 400m lb (200,000 tonnes) in 2006, to 10bn lb by 2015. The main drivers of this growth are consumer demand for environmentally-friendly products and the volatile price of petroleum. Europe’s crude oil and natural gas resources are limited so the reduction of the dependency on the current high imports of raw oils in Europe, being the domestic production not sufficient for satisfying the demand is high on the agenda, via the increased use of renewable sources as raw materials.

In terms of dissemination, the target audience was follows:
a) Packaging manufacturers and food producers
b) Food packaging equipment manufacturers
c) Other industry stakeholders and multipliers
d) Consumers and Retailers
e) Other market actors and stakeholders, such as the policy makers, regulatory and standards bodies
f) The academic community and early stage researchers, etc.
g) The general public.
The main dissemination materials are annexed to the report including a project poster, a leaflet- which was translated into English, German, Spanish, Catalan, Italian, Turkish-, an initial and final factsheet which gives an overview of main final results from the project as is as such considered as the publishable summary. Furthermore the project website ( which was visited by approximately 3000 persons per year gave updates on the project to the public. The presence of the project in a Euronews programme Futuris ( shall also be highlighted.
A total of 272 activities were reported (only selected ones have been entered in the participant portal in the second project period as agreed with the project officer, but a full list is annexed). They are quite well distributed along the 3 years of the project and of different types, including:
• 6 industry trade shows and exhibitions
• 91 posters and oral presentations in conferences
• 15 consultations from research community
• 70 face to face meetings
• 6 policy makers reached
• 91 press releases and articles published in the press/web
• 4586 hits on the project website in second reporting period
• 2 social media networks (Linked in; facebook)
• 3 scientific papers submitted (the last of which could not entered in the system as it is in press).
In addition, 5 demonstration events were organized.

In terms of exploitation, the target market for BioBoard technology (materials and processes) is following an upward trend towards more sustainable solutions and highly open to innovations. The foreground is broad and covers the whole supply and value chain and gives rise to potential exploitation opportunities for each member of the consortium. The results obtained in the project are promising but require significant further improvements to reach the demanding requirements of laminate packaging sectors. Nevertheless, they can also serve number of other applications and converting technologies, such as injection molding, extrusion or co-extrusion of multilayer plastic films, etc. In keeping with the need for further improvements of the BioBoard material to reach its industrialization (tests were done at TRL6 showing current limitation to overcome), selected partners have applied for proposals that would allow further developing the potato waste derived materials, one of which has just been approved for funding under the WASTE call.

List of Websites:

Dr. Elodie Bugnicourt
Avda Carl Friedrich Gauss 11
08860 Castelldefels
Tel: 00 34 935542503
Fax: 00 34 935542511