Caracterização técnica e avaliação ambiental de estruturas comerciais e de uma proposta monomaterial em embalagens flexíveis para molhos de tomate

Abstract

Tomatoes occupy a prominent position in the Brazilian agro-industry, being widely used in the production of sauces and other tomato-based products that require efficient packaging systems to guarantee protection, stability, and shelf life. In the flexible packaging segment, multimaterial structures formed by the combination of different polymers are widely used due to their mechanical and barrier performance; however, the complexity of these architectures compromises recyclability and hinders their integration into circular economy models, in a context of increasing environmental, regulatory, and productive efficiency demands. Given this scenario, this dissertation aimed to characterize commercial flexible packaging used for tomato sauces and evaluate the technical and environmental feasibility of transitioning to a predominantly monomaterial, technically recyclable, polyethylene-based alternative structure. To this end, five commercial stand-up pouch packages were analyzed and compared to two structures developed on a pilot scale, representative, respectively, of conventional multimaterial architectures and a predominantly monomaterial configuration. The methodology involved physicochemical, thermal, morphological, and functional characterization through differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, oxygen and water vapor barrier tests, evaluation of sealing behavior, coefficient of friction, basis weight, and thickness, in addition to Life Cycle Assessment (LCA), considering exclusively the packaging system. The results demonstrated that the commercial packaging evaluated is predominantly multi-material, which limits its recyclability, while the proposed monomaterial structure showed compatible technical performance in critical parameters such as thickness, basis weight, minimum sealing temperature, water vapor barrier, and external coefficient of friction, although with a reduction in the oxygen barrier and a more restricted thermal sealing window. The LCA indicated a significant reduction in the total environmental impact of the monomaterial structure, associated with the simplification of the composition and the feasibility of mechanical recycling at the end of its life. It should be noted, however, that the tests performed were conducted under laboratory conditions, and further studies on an industrial scale are necessary, including tests on filling and packaging machines, to confirm the operational robustness and consolidate the applicability of the monomaterial structure as a viable alternative to conventional multimaterial packaging.