Using life cycle assessment to quantify the environmental benefit of upcycling vine shoots as fillers in biocomposite packaging materials

Abstract

Purpose The objective of the present study was to better understand the potential environmental benefit of using vine shoots (ViShs), an agricultural residue, as filler in composite materials. For that purpose, a comparative life cycle assessment (LCA) of a rigid tray made of virgin poly(3-hydroxybutyrate-co-3-hydroxyvalerate) PHBV, polylactic acid (PLA) or polypropylene (PP), and increasing content of ViSh particles was performed. The contribution of each processing step in the life cycle on the different environmental impacts was identified and discussed. Furthermore, the balance between the environmental and the economic benefits of composite trays was discussed. Methods This work presents a cradle-to-grave LCA of composite rigid trays. Once collected in vineyards, ViShs were dried and ground using dry fractionation processes, then mixed with a polymer matrix by melt extrusion to produce compounds that were finally injected to obtain rigid trays for food packaging. The density of each component was taken into account in order to compare trays with the same volume. The maximum filler content was set to 30 vol% according to recommendations from literature and industrial data. The ReCiPe 2016 Midpoint Hierarchist (H) methodology was used for the assessment using the cutoff system model. Results and discussion This study showed that bioplastics are currently less eco-friendly than PP. This is in part due to the fact that LCA does not account for, in existing tools, effects of microplastic accumulation and that bioplastic technologies are still under development with low tonnage. This study also demonstrated the environmental interest of the development of biocomposites by the incorporation of ViSh particles. The minimal filler content of interest depended on the matrices and the impact categories. Concerning global warming, composite trays had less impact than virgin plastic trays from 5 vol% for PHBV or PLA and from 20 vol% for PP. Concerning PHBV, the only biodegradable polymer in natural conditions in this study, the price and the impact on global warming are reduced by 25% and 20% respectively when 30 vol% of ViSh are added. Conclusion The benefit of using vine shoots in composite materials from an environmental and economical point of view was demonstrated. As a recommendation, the polymer production step, which constitutes the most important impact, should be optimized and the maximum filler content in composite materials should be increased.

Introduction to the special issue “Sustainability Issues of Food Processing and Packaging: the Role of Life Cycle Assessment”

“…The study highlighted that the two bioplastic matrices tested in the study, namely PLA and PHBV, exhibited higher environmental impacts than the fossil-based PP. David et al (2020) believe that such a finding should be, however, tempered by the fact that PP-derived long-term impacts like plastic accumulation were not considered in their study, and that bioplastic production has not yet reached competitive levels of technological advancements. In addition to this, the authors documented that the increase of VS particles as filler in plastic tray manufacturing resulted in environmental impact reduction, despite of the additional processing steps that were required for the VS filler production and of the higher VS filler density compared with the three polymeric matrices investigated.…”

“…In their contributions, the authors explored relevant sustainability issues of food SCs, thereby enhancing the current state-of-the-art in the field. Most of them focussed upon packaging materials and technologies, as done by David et al (2020), Del , Gallucci et al (2020), Stefanini et al (2020), and Yang and Rosentrater (2020), whilst Bianchi et al (2020) and Sasaki et al (2021) investigated the entire SC of foods with particular attention on the packaging factors that influence their environmental profiles.…”

“…Plastic continues to be increasingly produced as it is characterised by high levels of versatility, hygiene, flexibility and durability, which make it suitable for a wide range of applications: food packaging is one of those, mainly owing to the ability of plastic to best preserve foods (Stefanini et al 2020). In this SI's paper collection, the environmental sustainability of food plastic packages was explored by David et al (2020 and Stefanini et al (2020), also in comparison with alternative materials.…”

“…In their study, David et al (2020) explored the environmental feasibility of reutilising Vine Shots (VSs) as natural fillers to be incorporated into polymer matrices. In particular, the authors carried out LCA to understand to what extent the usage of VS fillers makes packaging trays more environmentally sustainable than those produced for 100% virgin polymer.…”

Wine By-Products as Raw Materials for the Production of Biopolymers and of Natural Reinforcing Fillers: A Critical Review

“…It can be firstly noticed that there are no significant differences in terms of particle density (1.36–1.44 g/cm 3 ). Nevertheless, from an applicative point of view it is useful to report that grape stalks and vine shoots, before grinding operations, have a very low apparent density (around 0.03 g/cm 3 ) [ 154 ] that could affect the transport costs during large-scale operations. In terms of mean particle size, wine lees have exhibited the lower values (D 50 of 25 μm) [ 146 ] and grape seeds the highest (D 50 of 750 μm) [ 155 , 156 ].…”