Fostering sustainability in the olive oil supply chain: valorization of typical virgin olive oils and olive mill by-products

The olive oil supply chain needs to face different sustainability challenges: preservation of territorial identity, promotion of high-quality typical products, necessity to improve by-products and optimize waste management. This PhD project aims at fostering sustainability in the olive oil supply chain through two main objectives: the valorization of typical virgin olive oils (VOOs) and the valorization of olive mill by-products (OMByP). For the first objective, three case studies were considered, characterizing chemically, instrumentlaly, and sensory VOOs from Albania, Morocco, and Portugal (three samples of Azeite de Moura and three of Azeite de Trás-os-Montes) were chemically, instrumentally, and sensory characterized. The Albanian case study provided the first comprehensive characterization of the Kalinjot cultivar, highlighting distinctive chemical and sensory traits consistent with EU extra virgin standards and supporting the basis for a future Geographical Indication, though further sampling is required. The Moroccan study on Huile d’olive de Béni Mellal (Picholine Marocaine) identified characteristic features suitable for a potential EU PGI application, while underlining the need for greater quality consistency across production batches. The Portuguese case study on Azeite de Moura and Azeite de Trás-os-Montes generated updated chemical and sensory data to support PDO specification revision and emphasized the importance of improving post-harvest practices to ensure compliance with quality standards. The second objective was conducted within the PNRR AgriTech project, focusing on OMByP quality improvement and valorization. This included both a review of existing strategies and the testing of an innovative approach for olive leaves, co-digested with olive mill wastewater (OMWW) to explore their potential for biogas production. Results showed how the addition of a low percentage of pulverized olive leaves did not impact the biogas production nor the biogas composition. Co-digesting OMWW with small percentage of olive leaves did not affect biogas production and improved biogas quality by increasing methane-to-CO₂ ratio.