The goal of the project was to prove and demonstrate the viability of an innovative technology for the production of a bio-lacquer obtained from tomato by-products and to be used as coating for food contact applications in metal cans.
The main objective of the project involved the design and building of a pilot plant on semi-industrial scale to prove the technical feasibility and the efficiency of the cutin extraction and production system developed and set up at laboratory scale in a previous project (FP7, BIOCOPAC). The tomato cutin is a polyester biopolymer interesterificated with potential to replace petroleum for the synthesis of polymer and for the production of thermosetting resins, the main component of the new eco-lacquer. The reproducibility of the extraction process was another important goal.
The second objective was the formulation and the application of a bio-lacquer, with quality and safety properties comparable with the standard oil based lacquers and with technological characteristics suitable for the application on standard line.
The third objective was to establish the shelf-life of different foodstuffs packed in the new cans in comparison with standard ones.
Secondary objectives were the optimization of the pilot plant for cutin extraction in terms of resources efficiency and saving (water, energy, emissions); the demonstration of the compliance of the new bio-lacquer with hygienic-sanitary and sensory requirements; the evaluation of yield of the process and cost of the new lacquer; the survey of the retail and consumer acceptance of the new lacquer and the willingness to pay more for a bio-packaging.
Finally the project aimed to study the environmental impact of the extraction process and of the eco-cans by LCA.
Both the main target and the secondary objectives of the project were achieved as originally planned according to the project proposal, and they are specifically described in the deliverables and outputs produced. Only one aspect related to the optimization of purified cutin is still under investigation and will continue to be evaluated in the coming months.
The scale-up of the extraction method has been successfully carried out; the pilot plant has been designed, realized and assembled. The extraction method has been transferred from a laboratory scale to a pilot level, modifying only some parameters of the process and obtaining cutin with good qualitative characteristics, high yield (10-15%) and reproducibility.
The production of the new eco-lacquer for food metal packaging has been completely achieved: after the commissioning of the pilot plant, the industrial production of cutin has been performed. Overall on the plant about 450 Kg of cutin has been obtained; of these about 100 kg has been employed for the industrial synthesis of bioresin and the formulation of the bio-lacquer, that has been applied on tinplate, TFS and aluminium on industrial line. Then the cans has been industrially produced and filled with different food products. The corresponding pack tests are ongoing since several months (depending on the product). The results obtained are positive and comparable with those of the standard cans. The compliance of the bio-lacquer with national and European legislation was positive, with migration values below the legal limits.
A green extraction protocol has been assessed by using energy from renewable resources, by recirculating the solution and by improving the biogas production of the exhausted peels.
A positive LCA output was obtained in terms of reduction of the uses of the resources and CO2eq emissions. For each cans up to 730 mg/CO2eq is avoided.
Through questionnaires and interview the interest of retailer and consumer for the new lacquers was confirmed.
Thanks to the cutin extraction prototype, the valorization of the tomato by-products by upgrading them to higher value and useful product has been achieved, at the same time offering alternatives strategies for the waste use and minimization in accordance with Directive 2008/98/EC.
The approach developed in the project is a concrete example of circular economy; a virtuous loop “from tomato to tomato” has been created: the by-products of the tomato industry has been utilized for cutin extraction, then used as starting material for the formulation of the bio-lacquer, that has been applied on the internal surface of the tomato cans (and not only of course).