Pine Resin: Untapped Potential for Sustainable Industrial Innovation

The bark of *Pinus radiata* is an abundant and renewable forest residue, predominantly underutilised or burnt to generate energy and heat. However, several studies have shown that this bark contains a high proportion of phenolic compounds and suberin, compounds that have the potential to develop innovative materials with bactericidal properties. This project went one step further, applying a green strategy to extract the lipophilic constituents of the bark and suberin using supercritical carbon dioxide (scCO2) at different temperatures and pressures, with a biocompatible ionic liquid catalyst. This technique revealed that the scCO2 extracts contained predominantly resin acids, while the extracted suberin had a structure rich in alkanoic acids, rare in other sources. Innovation in extraction methodology now makes it possible to segment the valuable constituents of *Pinus radiata* bark. Through green and sustainable technologies, such as the use of scCO2, extraction is carried out in multiple steps: 1. Extraction of soluble organic compounds from the bark; 2. Subsequent extraction of suberin, a structure composed of cell wall polymers. The study concluded that the yield of the secondary by-product (suberin) is estimated at 2.25 per cent by weight, and the lipophilic compounds reach up to 5.2 per cent by weight. This effective process with green solvents positions bark biorefineries as a practical and environmentally friendly solution, converting forest residue into high added value compounds. The success of this project implies the creation of new opportunities for forest owners, scientists and farmers. The ability to transform previously under-utilised waste into high-value products not only generates a new source of income but also promotes forest sustainability. In the modern era of the chemical industry and the sustainable management of natural resources, the forest has a new protagonist that is emerging with significant potential: the bark of Pinus radiata. The ‘Pinus Resina’ project, focused on identifying compounds of industrial interest, presents an innovation that could revolutionise the use of undervalued forest residues. This project not only emphasises sustainability, but also offers new economic opportunities for forest owners, scientists and farmers. The *Pinus Resin* initiative has a well-defined mission: to identify and establish new value chains that competitively and safely transform and valorise pine resin, contributing to the sustainability and competitiveness of Portugal's maritime and stone pine forests. This endeavour aims to strike a balance between innovation and forest conservation, promoting more efficient management and differentiation in the global market. Specific objectives include: The full valorisation of gum resin (RG); Development of an environmentally responsible industry; Evaluation of the variables that influence the composition of GRI; Sustainability of the biotransformation process; Comparative analysis of the products obtained (benchmarking); Development of a co-operation network; Widespread dissemination of the project. Pine Resin: Untapped Potential for Sustainable Industrial Innovation Unlocking New Value Chains Figure 1. Schematic model of a potential sustainable bark biorefinery FOREST4EU Project FOREST4EU Project [email protected] Contacts Further information forest4eu.eu Funded by the European Union (Grant n. 101086216). Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union or REA. Neither the European Union nor the granting authority can be held responsible for them. partners: João Nunes ([email protected]) More information about PinusResina operational group. With biorefineries centred on the bark of *Pinus radiata*, the integrated approach of *Pinus Resina* can serve as a model for other forestry initiatives. The additional yield from the bark after extraction of lipophilic compounds and suberin also improves the thermal stability of the remaining materials, which can be used in polymer-wood composites, further expanding industrial applications. By joining forces between scientific, forestry and industrial organisations, new routes to sustainability and economic growth can be mapped out, ensuring a greener and more prosperous future for all. As the *Pinus Resin* project progresses, it becomes crucial to carry out complementary technological and economic analyses to establish the most efficient value chains. Identifying new products and optimising extraction operations could be a significant step forward for the industry. In addition, the experience gained with *Pinus radiata* bark could inspire similar research with other tree species, thus extending the positive impact on the management and valorisation of forest resources at a global level. The *Pinus Resina* project highlights the importance of innovation and research in maximising the potential of forest resources. With its sustainable and technological approach, this project not only brings financial benefits to the stakeholders involved, but also promises responsible and innovative exploitation of Pinus forest resources. The Way Forward