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Valorisation of legumes co-products and by-products for package application and energy production from biomass

Final Report Summary - LEGUVAL (Valorisation of legumes co-products and by-products for package application and energy production from biomass)

Executive Summary:
The public awareness on sustainability and the implementation of environmental regulations especially regarding waste disposal which limit the use of petroleum based plastics in applications where recycling is not easy, push the industry to find new alternative to such materials. According new market demands, bio-based plastics have found wider acceptance in the industry because they lead the reduction of greenhouse emission and reduce the dependence on crude oil, however the concern for the use of raw materials competitive with the food have increased.

Food waste valorisation has attracted a great deal of attention as alternative. In general, vegetal residues are rich in various added valued which under extraction could constitute a source of interesting revenues for these industries. In particular LEGUVAL project targets the valorisation of by-products from the legume processing industry which are currently discarded to be used in the preparation of materials for agriculture, packaging and automotive applications for the plastic industry.

In particular, this project adopted the following three strategies:
1. Use of protein for bioplastic production. The protein-rich fraction was extracted from legume by-products to develop new biodegradable protein films and coatings with enhanced barrier properties for packaging applications.
2. Remaining fibres were used for composite production by incorporation into a polymer matrix to improve mechanical and barrier properties of biodegradable polymers.
3. The leftover biomass was used for energy generation by anaerobic digestion.

The most relevant achievements of the LEGUVAL project were the following:

1. A simple and sustainable method for extracting proteins and fibers from legume by-products, achieving high percentages in the final extracts.
2. A recyclable, non-toxic and environmentally friendly multilayer system based on PLA and LEGUVAL coating with improved barrier properties.
3. A biodegradable formulation to convert legume protein powder into thermoplastic material, and suitable processing conditions for its plasticization and transformation.
4. A formulation to prepare bio-based and biodegradable composites based on a plasticised bio-based polymer matrix added with legume fibres, and suitable processing condition for the transformation of the developed biodegradable formulation.
5. Fibers-rich fractions isolated during the treatments of legumes by-products were used as source of biogas in continuous mode reactors.
Project Context and Objectives:
The overall objective of the LEGUVAL project is to develop a series of bio-based materials from legume by-products to replace conventional fossil fuel-based plastics. This green strategy will reduce residues from legume industry, will add new value to legume by-products as well as greatly improve the sustainable production of plastics.

In order to achieve the above, the technical and operational objectives that needed to be fulfilled over the course of the project are provided bellow:

1 Valorise co- and by-products of legume conserve production
2 Optimise protein extraction from the legume by-products
3 Use the legume proteins for the production of films and coatings to be applied on plastic film or paper (barrier properties) in multilayers packaging by wet process
4 Use the legume protein in plastic processing as a nitrogen rich, biodegradable additive for applications such as agriculture pots, packaging films or edible packaging
5 Use the biomass leftover from protein extraction for application as a filler in bio-composites
6 Use of the final leftover biomass from protein extraction for biogas production
7 Evaluation of aerobic (composting) and anaerobic decomposition (biogas production) of bio-based products (multi-layers films, blends and composites), based on legume protein and biopolymers as preferential disposal pathway and Life Cycle Assessment of developed products selected for industrial production
8 Demonstration of protein extraction feasibility and use of biomass in eco-compatible products
9 Validation of the innovative packaging materials performance in automatic Packaging Lines
10 Disseminate project results without compromising patent applications (rule for dissemination), and organise workshops and training courses to make legume producers aware of the possibilities to valorise their by-products and plastic producer aware of availability of biodegradable material from renewable resources with no food competition and valuable properties of protein materials and cheap filler derived by left over biomass

Project Results:
The project started by reviewing the current situation of the legume processing business and analysing the needs of the plastic industry in WP1 (State of the art and definition of stakeholder needs and industrial specifications). To this aim, both the industry and research partners worked closely in developing questionnaires and contacting stakeholders to gather information first about the composition, amount and current uses of legume by-products and second about market demand specification of bio-plastic materials. In addition, a comprehensive literature review was carried out in order to determine current processing methods and final properties of target materials. Additionally, a patent review was carried out and concluded that LEGUVAL does not infringe upon existing protected intellectual property (IP).

As part of WP2 (Legumes by-products treatment), legume by-products types to be used for the project were identified by considering different criteria, mainly production volumes, percentage of by-products obtained, origin and seasonality. From each family of legume by-products, representative samples of the different lots were taken and characterized. On the basis of the results obtained at lab scale, by-products from peas, lentils and beans were pre-selected as starting raw materials for proteins and fibres extraction at pilot scale. Finally, pea by-products were selected due to the simplicity of the matrix, good processability, availability and quantitative yield as raw material. An innovative method to extract proteins at Pilot scale from such by-products with a purity degree close to 80% was developed and optimized.

As part of WP3 (Legume Protein Films and Coating by WET Processes), starting from legume proteins, several studies at lab scale were carried out in order to establish the most appropriate way to denature the different protein received and obtain an optimal film forming solution for each protein under consideration. The most appropriate additives were selected in order to develop protein based edible films by wet process, and films from lentil and peas were prepared by choosing the most appropriate parameters. The optimum protocol for both types of legumes was established. Edible film based on pea proteins with a barrier properties improvement factor of 7-10 vs PET at 50% humidity was developed. Good adhesion on PLA film surface was achieved in application at lab scale. Application of the coating formulation developed on a PLA film produced a significant reduction of Water Vapour Permeability and Oxygen Permeability with respect to uncoated PLA. The migration tests performed indicated that this material can be used as a packaging material for fresh products with a short shelf-life or for dry foods with a longer shelf-life. A PLA/LEGUVAL coating/PLA multilayer system was obtained by a laminating process. For the application of this fully compostable multilayer system as packaging material, shelf-life studies on Gouda cheese were carried out.

As part of WP4 (Legume Protein Films and Coating by DRY Processes), protein extract was used for developing biodegradable plastic materials based on protein, by plasticization and blending with biodegradable additives and polymers through dry-process as part of WP4. Formulation was adjusted for the production at pilot scale; in particular, additive amount was fine-tuned and processing parameters were optimized. Finally, films and packaging plant pots were produced with standard extrusion and injection moulding technology respectively to show the feasibility of LEGUVAL materials.

As part of WP5 (Biomass as filler in composites), most promising formulations and items produced from the selected formulation were characterised by IPCF-CNR for thermal, mechanical properties and measurement of gas and water vapour permeability by SSICA. Measurements of contact angle were performed by IPCF-CNR, and other relevant properties connected to packaging and agriculture applications (surface appearance, smell, extraction) as requested by the SME-AGs, their members and the Other Enterprises and End-users partners in the Consortium. In particular, for application in food packaging, SSICA carried out tests to evaluate the hygienic-sanitary properties of the items based on risk assessment. In particular, conformity tests on contact with simulant under the worst foreseeable conditions were conducted, such as overall and specific migration tests as well as residual monomer tests, on the basis of prevailing food safety legislation (Reg. 1935/2004/CE; Reg. 10/2011). Degradability tests to asses biodegradability of materials intended for agricultural applications was carried out at IPCF-CNR (see WP6 for further details). The most promising formulation selected by IPCF-CNR was produced on kilogram scale on a extruder at IPCF-CNR and tested for film productions and injection molding at SME members of SME-AG PCS from Slovenia.

As part of WP6 (Biogas production), fibres-rich fractions isolated during the treatments of legumes by-products were evaluated as source of biogas at lab scale. First experiments carried out in batch system allowed to state the suitability of such materials as substrates for anaerobic digestion, as they gave BPP (biogas production potential) values (around 300-400 m3/tVC) comparable with those reported for common substrates used in real plants. Good results were obtained also in continuous system with treated peas by-products, the best substrate in batch system: quite high daily biogas volumes around 700 m3/tVC, of which 50% was methane. Besides, in order to record the same biogas production, lower amounts of treated peas are required in comparison to untreated ones, probably because the treatment of by-products contributes to increase the availability of organic compounds for anaerobic digestion. However, as biogas conversion efficiency referred to absolute amount of these substrates is lower than that reported for energy crops usually used, the option of co-digestion was evaluated for the valorization of their anaerobic digestion potential; the results were promising.

As part of WP7 (Biodegradability and environmental impact), materials produced in WP3, WP4 and WP5 were tested for biodegradability in compost and soil. Tests were performed, in particular for composting, according to running standard for disintegration and mineralization. The materials were based on the formula selected for the production of LEGUVAL demonstrators as outcome of selection performed in WP3, WP4 and WP5 for coating of protein on PLA films, items based on peas protein and biodegradable polyersters, and composites based on polylactic acid and peas fibres. The materials respected the standards for disintegration in compost and mineralization in compost, and materials based on peas protein presented degradation even in soil. The performance in anaerobic digestion were also evaluated reproducing results reported in literature for materials with composition similar to LEGUVAL demonstrators. The Life Cycle Assessment outlined the possible low impact due to se of peas protein and peas fibres since bio-based materials produced with a sustainable process, achieved with an optimization of peas protein extraction process with recovery and re-use of water and chemicals.

As part of WP8 (Validation and demonstration), the bilayer and multilayer materials developed at semi-industrial scale in the final stage of the LEGUVAL project were validated for their use as packaging material for food. Three LEGUVAL demonstration events were also executed as part of this WP coinciding with the last thre project General meetings in Spain, Slovenia and Italy. The purpose of these sessions was to introduce the audience to the LEGUVAL project and outcomes. Where possible, LEGUVAL processes and assets ere demonstrated in-situ.

In terms of Dissemination, the public website of the project (http://www.LEGUVAL.eu) informs to the public and interested parties about latest news and the progress of the project. Various press releases were circulated in professional packaging technology magazines and websites, raising the awareness of LEGUVAL both in industry and in the public domain. In addition, scientific poster were prepared and LEGUVAL results was presented in seminars and scientific conferences. The project partners also took part in number of events and trade fairs reaching all target publics.

Potential Impact:
LEGUVAL partners have a vision of bringing new bio-based and biodegradable materials to the plastic industry to use it as alternative to current petrol derivatives in packaging, agriculture and composite applications. In particular, it is expected to find an alternative to current materials with high barrier properties in multilayer systems, as well as new extrudable biodegradable materials with improved properties.
There are numerous socio-economic impacts that will be derived from the results of the LEGUVAL research project beyond the consortium. Climate change, pollution and energy crisis are major issues that humanity will be facing in future years. Sustainable development has become a priority for the world’s policy makers. The possibility to use LEGUVAL to replace oil-based materials is of particular benefit for the EC since petro-derived polymers make a significant contribution to CO2 emission, with negative and health impact as well as contribute to the depletion of fossil resources. In addition, the project contributes with a solution to the environmental problems from the disposal of by-products from legume processing industries, adding a new value to their by-products and co-products. Indeed, the waste legislation and policy of the EU Member States shall apply as a priority order the following waste management hierarchy: 1) prevention, 2) preparing for re-use, 3) recycling, 4) recovery and 5) disposal, so according with this directive the valorisation of by-products has to be considered previous to the waste consideration and in all the cases the owner of these wastes is the last responsible person of the adequate management of these wastes with legal responsibility about it. As a consequence, food waste valorisation is attracting a great deal of attention as a potential alternative to the disposal in landfill sites for the Industry.
In particular, the development of innovative strategies to process such waste for develop new biodegradable coatings and plastic materials will further contribute to enlarge the basis of renewable materials for plastic industry no competitive with food resource and decrease the need for non-renewable raw materials with a consequent better use of resources.
In 2012 the plastic production rose 288 MT, whereas the production of bioplastics rose 1.6 MT according European Bioplastics. The market data show a forecast of 6.7MT in 2018, however the use of these products have been limited due to lower performance compared to traditional plastics and issues related to infrastructure or cost. To overcome these issues is one of the main challenges of this project.

List of Websites:
www.leguval.eu

Dr. Edurne Gaston Estanga / Dr. Elodie Bugnicourt
egaston@iris.cat / ebugnicourt@iris.cat
+34935542500