Introduction
Over the past three decades, the olive oil sector has seen substantial advancements driven by innovation in both processing equipment and farming practices, as well as an increasingly quality-conscious market. This evolution reflects a shift from traditional methods to scientifically supported practices aimed at optimizing oil extraction and by-product management. Central to these improvements is the integration of circular economy (CE) principles and life cycle assessments (LCA) to reduce environmental impacts and achieve sustainability goals.
This systematic literature review (SLR), conducted by Cinardi et al., aimed to explore the application of CE principles within the olive oil sector through the lens of LCA. This review systematically analyzed 15 studies, employing the PRISMA model to ensure comprehensive and comparable insights into the environmental impacts associated with extra-virgin olive oil (EVOO) supply chains.
Olive Oil Production and Environmental Impacts
Olive oil production is a critical agricultural sector, particularly in Mediterranean countries, and contributes significantly to their economies. However, the environmental impacts of this sector are multifaceted and include abiotic resource depletion, global warming, ecotoxicity, acidification, and eutrophication. These impacts vary based on cultivation practices, processing methods, and waste-management strategies.
Historically, this sector has faced challenges in balancing production efficiency with environmental sustainability. Modernizing facilities and adopting advanced technologies are recognized at the institutional level and supported by initiatives such as the European Union’s funding for innovation and mechanization in the agri-food sector.
Life Cycle Assessment (LCA) and Circular Economy (CE)
LCA is a valuable tool for evaluating the environmental performance of products throughout their life cycle from raw material extraction to end-of-life disposal. It provides a detailed analysis of input/output inventories and identifies environmental hotspots, thus supporting the implementation of sustainability-oriented improvements. Within the olive oil sector, LCA helps companies prioritize actions to achieve sustainable development goals (SDGs) related to responsible consumption and production, climate action, and life on land.
The CE principles, which focus on closing resource loops through waste reduction, reuse, and recycling, align well with the LCA methodologies. In the olive oil sector, CE applications include valorizing by-products, such as olive pomace (OP), olive mill wastewater (OMWW), and waste cooking oil, to produce bio-based materials and energy sources.
Systematic Literature Review Methodology
This review followed a systematic approach based on the PRISMA model, ensuring a rigorous and transparent selection process. The authors searched for relevant articles in the Scopus and Web of Science databases, using predetermined keywords related to olive oil production, LCA, and CE principles. The initial search yielded 58 articles, which were screened and refined to obtain a final sample of 15 studies published between 2012 and 2022.
These studies were clustered into two main categories based on their approach to byproduct utilization: closed-loop and open-loop systems. Closed-loop systems reintegrate by-products into the same production system, whereas open-loop systems use by-products in external processes.
Closed-Loop Systems
The review identified five studies that focused on closed-loop systems, highlighting their effectiveness in reducing environmental impacts. For instance, Salomone and Ioppolo (2012) conducted an LCA of olive oil production in Messina, Italy, comparing various by-product management scenarios. They found that composting wet olive pomace (WOP) with manure or using it in a compost machine significantly reduced the environmental impacts compared to traditional practices.
Similarly, Ncube et al. (2022) explored the use of OP oil extraction and biomass residues for energy purposes, demonstrating that these practices resulted in lower environmental impacts owing to the avoidance of grid electricity and traditional fuels. The study also emphasized the benefits of organic farming practices in further reducing the impact.
Open-Loop Systems
The remaining ten studies were categorized as open-loop systems, in which by-products were utilized in processes outside the olive oil production system. For example, Parascanu et al. (2018a) examined the environmental impact of pyrolysis in valorizing olive pomace, highlighting its potential for producing biofuels and reducing waste.
Another study by Batuecas et al. (2019) focused on the anaerobic digestion of OP and OMWW to produce biogas, which can be used to power oil production facilities. This approach not only reduces the environmental footprint, but also provides a sustainable solution for managing waste.
Key Findings and Best Practices
This review revealed several best practices for integrating CE principles into the olive oil sector. These include:
Valorization of Olive Pomace (OP): Extracting OP oil and using it for energy or agricultural purposes can significantly reduce the environmental impacts. Composting OP with other organic wastes or using it in anaerobic is an effective strategy.
Organic Farming Practices: Adopting organic farming practices reduces the environmental impact of the agricultural phase, which is often the most impactful stage in the olive oil lifecycle.
Industrial Symbiosis: Promoting proximity between processing plants and creating eco-industrial parks can enhance resource efficiency and sustainability. For example, waste cooking oil can be used to produce biodiesel and integrate biogas production within the supply chain are promising approaches.
Advanced Extraction Technologies: Two-phase extraction methods, which reduce water usage and produce oil with higher antioxidant content, can lower the environmental footprint compared to traditional three-phase methods.
Packaging and Waste Management: Sustainable packaging solutions and efficient waste management practices such as recycling and energy recovery are crucial for minimizing the overall environmental impact of the olive oil supply chain.
Challenges and Future Directions
Despite progress made in integrating CE principles and LCA in the olive oil sector, several challenges remain. The heterogeneity of LCA studies, including differences in functional units, system boundaries, and impact categories, complicates comparisons and generalizations. Standardizing methodologies and establishing common criteria for LCA studies can enhance comparability and reliability.
Further research is needed to explore the long-term sustainability of various CE paths and their potential trade-offs. For instance, although anaerobic digestion and pyrolysis offer promising solutions for waste management, their scalability and economic viability require further investigation.
Conclusion
The systematic literature review conducted by Cinardi et al.. underscores the importance of integrating circular economy principles into the olive oil sector through life cycle assessments. By valorizing by-products, adopting sustainable farming practices, and enhancing industrial symbiosis, this sector can achieve significant environmental benefits and contribute to global sustainability goals.
Future research should focus on standardizing LCA methodologies, exploring new CE applications, and addressing economic and social dimensions of sustainability. By doing so, the olive oil sector can continue to innovate and lead the way towards a more sustainable and circular economy.
Read more at: Cinardi, G., D’Urso, P. R., Arcidiacono, C., & Ingrao, C. (2024). Accounting of circular economy principles in Life Cycle Assessments of extra-virgin olive oil supply chains–Findings from a systematic literature review. Science of The Total Environment, 173977. https://doi.org/10.1016/j.scitotenv.2024.173977