In the Mediterranean, olive oil and wine are more than just iconic products: they have shaped landscapes, economies, and cultures for centuries. Behind this age-old tradition, however, lies a current problem: both supply chains generate large quantities of organic waste, which, if improperly managed, can become a burden to the environment. The study by Rodríguez-Pérez and colleagues addresses this very issue and proposes a shift in perspective: viewing these residues not as waste to be disposed of, but as resources to be valorized within a circular agri-food model.
Byproducts of olive milling (pomace, vegetation water, leaves, and pruning residues) and winemaking (pomace, stalks, lees, and wastewater) are rich in bioactive compounds, such as polyphenols, fiber, organic acids, and tocopherols. Compounds such as hydroxytyrosol, tyrosol, oleuropein, and resveratrol have well-documented antioxidant, anti-inflammatory, and neuroprotective properties. The study highlights the importance of green and efficient extraction techniques (such as ultrasound-assisted extraction, microwave extraction, or supercritical fluid extraction) to obtain high-quality functional ingredients.
The main innovative element lies in the proposal for joint valorization, which simultaneously considers the by-products of both supply chains. This integrated approach is rarely adopted despite its advantages in terms of resource optimization, cost reduction, and potential synergies between bioactive compounds. Specifically, the work described here proposes the combined use of grape marc and pomace in functional and enriched foods (bread, yogurt, chocolate, pasta, meat, and dairy products), with promising results in terms of antioxidant capacity, nutritional value, and extended shelf life.
Another aspect addressed concerns their applicability in the livestock sector, where by-products have been successfully used as feed ingredients, improving meat quality and reducing oxidative stress in animals. Opportunities also emerge in the wine and olive oil tourism sectors: joint promotion and territorial use strategies could strengthen local identity and extend tourism stays in rural areas.
From a regulatory perspective, the study calls for updating national and European legislative frameworks to facilitate the use of these by-products in food, currently hampered by regulatory constraints that favor centralized and costly approaches that are difficult for small and medium-sized businesses to access.
Finally, the study highlights the urgent need for a systemic transition driven by scientific innovation, regulatory flexibility, and consumer engagement, to transform agri-food by-products from waste to resources. The co-valorization of olive oil and wine waste represents a promising strategy for a more sustainable, resilient, and culturally rooted Mediterranean agriculture.
Bibliographic references: Rodríguez-Pérez, M.; García-Béjar, B.; Burgos-Ramos, E.; Silva, P. Valorization of Olive Oil and Wine Industry Byproducts: Challenges and Opportunities in Sustainable Food Applications. Foods 2025, 14, 2475. https://doi.org/10.3390/foods14142475
