"By choosing olive oil you support a more sustainable agricultural system, which protects the environment and promotes rural development."

Interview with Ramzi Belkhodja, coordinator of Plant Production, Health and Improvement at CIHEAM Zaragoza.

What are the main factors that determine the quality of olive oil?

The quality of olive oil depends on several factors that influence its chemical composition and organoleptic properties. The main factors are:

• Olive variety: Each type of olive contributes specific characteristics to the oil, such as flavour, aroma, and fatty acid content. Varieties such as Arbequina, Picual, or Hojiblanca produce oils with different sensory profiles.
• State of maturity of the olive: Harvesting at the optimum moment is key. Greener olives produce more intense and pungent oils, while riper olives generate smoother oils.
• Harvesting method: Hand or mechanised harvesting must be careful to avoid damage to the olives, which can increase the acidity of the oil and affect its quality.
• Climatic and soil conditions: Climate, altitude, soil type and agricultural practices (irrigation, fertilisation) affect both the quantity and quality of the oil. Factors such as sun exposure and the amount of water available influence phenolic and aromatic compounds.
• Storage time and conditions: Delays between harvesting and processing negatively affect quality, as damaged or fermented olives produce poorer quality oils. Prolonged or inadequate storage favours oxidation.
• Extraction method: The techniques used in extraction (cold pressing, centrifugation) determine the quality of the oil. Extra virgin olive oil is obtained by mechanical methods without the addition of heat or chemicals, thus preserving its properties better.
• Acidity and chemical composition: Free acidity (expressed as oleic acid) is a key quality indicator. Extra virgin olive oils must have less than 0.8% acidity. The content of phenolic compounds, antioxidants, and fatty acids also play a role.
• Oil storage: Storage conditions, such as temperature, light and exposure to air, have an impact on the stability of the oil. The oil should be stored in opaque containers in cool, dark places to prevent oxidation.
• Sensory tests (tasting): The organoleptic evaluation, carried out by panels of experts, considers factors such as fruitiness, bitterness and pungency. A good olive oil must have a harmonious balance between these attributes.

What are the main phytosanitary challenges facing olive production today and in the coming years?

Olive production faces a number of phytosanitary challenges that threaten crop health and long-term sustainability. These challenges are due to both emerging pests and environmental factors that favour their proliferation. The following are some of the main current and future phytosanitary problems:

• Xylella fastidiosa: This bacterium has been one of the major recent threats to olive groves in the Mediterranean, especially in Italy and Spain. It causes the rapid olive decline syndrome, which leads to the death of the tree. Xylella infections can devastate entire plantations, and so far, there is no effective cure. Strict quarantine measures and removal of infected trees are being implemented. The spread of Xylella due to climate change and the lack of resistant olive varieties are major concerns for the coming years.
• Olive fruit fly (Bactrocera oleae): This pest is responsible for significant damage to olive quality and yield. The larvae feed on the fruit, reducing its commercial value and affecting olive oil production. Olive fruit fly infestation can reduce oil yields and increase production costs due to the chemical and biological control required. Resistance of this pest to common insecticides and the need for more sustainable control methods are major challenges. In addition, global warming could favour its geographical spread.

• Verticillium dahliae: This fungus causes verticillium, a vascular disease affecting the olive tree, blocking the flow of water and nutrients. Symptoms include wilting and, in severe cases, death of the tree. It is particularly difficult to control, as the fungus can persist in the soil for years. Crop rotation and the use of resistant varieties are the main management strategies. Verticillium is expected to remain an increasing threat, especially in areas with infected soils and favourable climatic conditions for the fungus.
• Glyphodes or olive moth (Prays oleae): The olive moth is another important pest, affecting both leaves and fruit. In its larval stage, it causes direct damage to developing olives. Damage can significantly reduce production, and control of this pest requires a combination of biological and chemical techniques. Integrated Pest Management (IPM) strategies are needed to reduce the use of plant protection products, looking for more environmentally friendly and sustainable solutions.

The continued use of pesticides has led to some pests developing resistance, reducing the effectiveness of traditional treatments. This increases production costs and the need for new control approaches. The search for sustainable alternatives, such as biological control and the use of resistant olive varieties, will be key in the coming years.

The global movement of goods and climate change are favouring the emergence of new pests, such as the olive beetle (Phloeotribus scarabaeoides). These emerging pests require constant vigilance and the adaptation of new management strategies. Phytosanitary monitoring and international collaboration will be essential to prevent the spread of new threats.

In terms of genetic improvement, what advances are being made to develop olive varieties that are more resistant to pests or that give a higher fat quality to the fruit?

In the genetic improvement of olive trees, important advances are being made to develop varieties that are more resistant to pests and diseases, as well as to improve the quality of the fat in the fruit.

In terms of resistance to pests and diseases in the olive grove, important advances have been made.In the case of Xylella fastidiosa, a bacterium that causes serious damage to olive trees, research has focused on identifying resistant or tolerant varieties, using molecular genetic studies to search for genetic markers associated with resistance.The aim is to develop varieties that can survive in regions affected by this bacterium. For the fungus Verticillium dahliae, responsible for large production losses, breeding programmes are focused on selecting more resistant varieties, applying both traditional methods and biotechnology.With regard to the olive fruit fly, one of the most damaging pests for oil production, varieties with greater resistance are being developed, and the identification of genes related to resistance makes it possible to select those that are less attractive to this insect.

Significant progress has been made in improving oil quality.Efforts are concentrated on improving the fatty acid profile, mainly by increasing the oleic acid content, which benefits both the health properties of the oil and its stability against oxidation.

In addition, the aim is to increase the content of phenolic compounds, which have antioxidant properties, improving not only the oil's stability but also its organoleptic characteristics and health benefits.

In terms of adaptation to changing climatic conditions, genetic improvement is oriented towards the development of olive varieties tolerant to drought and water stress, which are essential to maintain productivity and oil quality in regions with limited water resources. Varieties are also being developed that can withstand high temperatures and saline soils, which is crucial for areas affected by desertification and salinisation.

Finally, the use of biotechnology techniques such as CRISPR/Cas9 is being explored to edit specific genes that influence pest and disease resistance or improve oil quality-related traits. Although this technique is still under development for olive, it promises to accelerate the process of genetic improvement. In addition, marker-assisted selection (MAS) is facilitating the precise identification of genes of interest, allowing more efficient selection of genotypes with desired traits, such as increased disease resistance or improved fatty acid composition.

At the same time, breeding programmes are committed to the conservation of genetic biodiversity, focusing on the preservation and use of local or ancient varieties, which possess valuable traits for both disease resistance and the production of high quality oils. These varieties are sources of essential genes that, combined with modern techniques, can contribute significantly to the genetic improvement of the olive tree.

What major technological innovations are transforming olive production and processing for olive oil and how are these technologies helping to improve efficiency and sustainability in the milling and processing industry?

Technological innovations are transforming both olive production and olive oil processing, with a focus on improving efficiency, sustainability and quality of the final product. The following highlights the main technologies and their impact on the industry:

• Precision agriculture:

Sensors and real-time monitoring: using sensors in the field to measure variables such as soil moisture, tree nutritional status and ambient temperature allows for more efficient management of irrigation and fertilisation. This helps optimise the use of resources and improves olive yield and quality.
Drones and remote sensing:Drones equipped with multispectral cameras make it possible to monitor large areas of olive crop for diseases, pests or growth deficiencies. This technology helps to make accurate crop management decisions, reducing unnecessary use of agrochemicals and improving sustainability.

• Smart irrigation:

Automated and drip irrigation systems: these systems allow water to be applied more efficiently, optimising water consumption according to the exact needs of the olive trees. With climate change and increasing water scarcity, these systems improve the sustainability of production.
Controlled Deficit Irrigation (CDI): This technique adjusts irrigation to apply only the amount of water needed at key moments in the olive's development cycle, maximising fruit quality without wasting water.Mechanisation of harvesting:

• Automatic harvesters:

Mechanisation of harvesting, with machines that shake the trees or pick the olives directly from the ground or the plant, has improved harvesting efficiency. These machines reduce labour costs and harvesting time, helping to ensure that the olives are processed quickly to maintain oil quality.

Selective harvesting: Advanced equipment allows selective harvesting of olives at different stages of ripeness, which optimises the sensory profile of the olive oil obtained.

• Extraction and processing technologies:

Cold pressing and centrifugation: New cold pressing and centrifugation technologies have improved the efficiency of olive oil extraction, allowing higher yields to be obtained without affecting quality. These techniques better preserve phenolic compounds and antioxidants, guaranteeing high quality extra virgin olive oils.
Waterless decanting: This innovative technique avoids the use of water during the decanting process, reducing water consumption in processing and helping to reduce the production of liquid waste. This not only improves sustainability, but also better preserves the flavours and aromas of the oil.

• Automation and artificial intelligence in olive oil mills:

Automated parameter control: advanced automated control systems allow real-time monitoring and adjustment of critical parameters during milling, such as temperature, beating time, and centrifugation speed, to optimise oil yield and quality.
AI and machine learning: Artificial intelligence is being used to analyse large amounts of data from different processing stages. These systems can predict oil quality based on fruit and process characteristics, helping to improve decision-making and reduce human error.

• Energy optimisation:

Sustainable olive mills: processing plants using renewable energy sources, such as solar panels or biomass, are being introduced to reduce the carbon footprint of the production process. In addition, new energy recovery systems harness the waste heat generated in mills for reuse in other stages of the process.
Energy efficiency technologies: The incorporation of more efficient equipment, such as high-efficiency motors in processing machinery, reduces overall energy consumption in olive mills.

• Waste management and circular economy:

Use of by-products: The remains of the milling process, such as alperujo (a mixture of pulp and stone), can be used to produce biofuels or as raw material for the production of organic fertilisers or animal feed. These practices contribute to sustainability and allow waste to be transformed into valuable resources.
Wastewater treatment and reuse: Innovations in wastewater treatment allow the recovery of water used in processing for other purposes, such as irrigation, reducing environmental impact and improving water efficiency.

• Blockchain and traceability:

Digital traceability: the implementation of blockchain technology and digital traceability systems make it possible to follow the entire production process, from the cultivation of the olive to the final bottle. This not only guarantees the authenticity and quality of the oil, but also responds to consumer demands for transparency and sustainable origin.
Impact on efficiency and sustainability:

These technologies are helping the olive oil industry in a number of ways:

Cost reduction: Mechanisation and automation are reducing labour costs and optimising input use, which increases producers' profitability.
Higher quality: Automated extraction and control technologies are producing better quality olive oils, with a higher concentration of beneficial compounds and improved organoleptic properties.
Sustainability: Technologies focused on reducing water consumption, energy and waste generation are making the industry more environmentally friendly, responding to the growing demand for sustainable products.
Energy and water efficiency: Resource optimisation reduces dependence on non-renewable inputs and improves efficiency throughout the process, from cultivation to processing.

As president of the Scientific Committee of the World Olive Oil Congress, how would you assess the programme prepared for this edition? How important has this Committee been in conveying to producers and professionals in the sector the new developments and innovations existing in each link of the chain?

As president of the Scientific Committee of the World Olive Oil Congress, I am very satisfied with the programme developed for this congress in each of its segments. This event has been a resounding success, thanks to the dedication and effort of all the scientists and experts who have contributed to its preparation. During the three days of work, we have addressed a wide range of key issues for the future of the olive oil industry, from the challenges posed by climate change to technological innovations along the entire value chain, including health benefits and sustainable practices.

The discussions and presentations highlighted not only the importance of continuing to invest in research and development, but also the need to adopt new technologies that can improve the efficiency and sustainability of the sector. It has become clear that the way forward requires constant collaboration and knowledge sharing between all actors in the production chain. We must remain focused on quality and sustainability, which are key factors in ensuring the long-term success of the industry, as well as meeting consumer demands and environmental expectations.

This congress has shown that while we face significant challenges, we also have the ability to transform them into opportunities through innovation, scientific engagement and global collaboration.

The Scientific Committee of the Olive Oil World Congress (OOWC) has played a key role in the transfer of knowledge and the dissemination of innovations in the olive oil sector. Its work has been essential in connecting producers, researchers and professionals, creating a bridge between traditional challenges and the latest technological and scientific trends. Through a strategic selection of topics and speakers, the committee drives the adoption of advanced practices and sustainable solutions that are vital for the future of the sector.

In addition to being a pillar in the modernisation of the sector, the OOWC Scientific Committee ensures that advances in the industry reach all links in the value chain, promoting competitiveness and sustainability in olive oil production. This coordinated effort allows producers and professionals to be equipped to face future challenges more efficiently, ensuring a more resilient industry adapted to new market demands.

Below, I highlight some of the highlights of this committee's role at the congress:

- Update on Innovations: The committee carefully selects topics and speakers who present the latest research and technological advances in each link of the olive oil production chain, from the field to marketing. This allows attendees to have access to the latest pest management tools, extraction techniques, and marketing strategies adapted to the digital environment.

- Promoting Sustainability: One of the key objectives of the committee is to encourage more sustainable practices in olive oil production. Presentations and panels offer solutions based on technological innovation that help producers improve efficiency and reduce environmental impact, in line with European priorities such as the Green Pact and the digital transformation.

- Improving Competitiveness: By facilitating access to knowledge on new olive varieties, farm management systems and processing methods, the committee helps producers stay competitive in an increasingly demanding global market. Topics covered include improving oil quality, cost control, and strategies for certification of value-added products.

- International Collaboration: The congress, guided by the scientific committee, fosters collaboration between researchers and experts from around the world, promoting an exchange of ideas and experiences that benefit both small and large producers. This facilitates the adoption of more efficient and sustainable practices globally.

Finally, what message would you convey to consumers about the importance of olive oil as a differential vegetable fat in the Mediterranean Diet and as a socially and environmentally sustainable product?

Olive oil is much more than just a vegetable fat; it is a fundamental pillar of the Mediterranean Diet, widely recognised for its health benefits, its culinary versatility and its positive impact on society and the environment. Firstly, it is one of the healthiest fats available, rich in monounsaturated fatty acids and antioxidants such as polyphenols, which contribute to the prevention of cardiovascular disease and other health problems. Its ability to improve metabolic health and its role in balanced diets make it a fat that sets it apart from other alternatives.

Moreover, olive oil is not only a food, but also a socially and environmentally sustainable product. Olive oil production is deeply rooted in Mediterranean culture, sustaining rural economies and communities through employment and cultural heritage.In environmental terms, olive trees are a key source for combating desertification, enhancing biodiversity and acting as carbon sinks, helping to mitigate climate change.

Conveying this message to consumers is crucial: by choosing olive oil, they are not only making a healthier choice for their well-being, but also supporting a more sustainable agricultural system, which protects the environment and promotes rural development. This product represents the perfect balance between taste, health and sustainability.