How is sunflower oil produced?

The vegetable oil of sunflower is derived from sunflower seeds. Each year, approximately 16 million tonnes of oil is produced globally. The oldest method of extraction is cold pressing. This process begins with the harvesting and cleaning of the sunflower husks. These are then shelled to extract the seeds. After a thorough cleaning and drying, they are introduced into an oil press. Within the press, the seeds are mechanically compressed. This gentle pressure crushes the cells of the seeds, thereby releasing the oil they contain. The heat generated by the pressure is minimal.

Once the oil is extracted, it is separated from solid residues and hydrophilic compounds by centrifugation. Impurities such as colloidal matter, phospholipids, excess free fatty acids (FFA) and colouring agents are thus removed. The resulting oil is then filtered to eliminate the last unwanted particles. Cold pressing results in a high-quality sunflower oil, referred to as "virgin" or "extra-virgin", which retains its natural colour and properties. This oil can be used in the food industry or in cosmetics.

• Benefits : This is a completely natural and minimally polluting extraction method, which does not require the use of a chemical solvent. It is therefore environmentally friendly and uses relatively little energy. Moreover, it allows the preservation of the active ingredients and the quality of the oil as it takes place at a low temperature. This extraction method makes the oil more resistant to rancidity.

• Drawbacks : The yield obtained from cold pressing is relatively low compared to the use of other techniques such as solvent extraction.

Note: At Typology, we use cold-pressed sunflower oil for the formulation of our skincare products.

The solvent extraction method involves applying moderate pressure to the seed to extract the majority of the oil before using a solvent. This second step allows the separation of additional oil from the solid fraction. In practice, the seeds are placed in an extractor containing the solvent. This is most often hexane, an organic solvent. The oil, being miscible in this solvent, will then dissolve in it.

The mixture is then placed into an evaporator and heated to allow the solvent to evaporate. Following this, the obtained sunflower oil is refined to remove impurities. The solvent extraction process is the most widely used treatment method in the world today for the extraction of sunflower oil.

• Benefits : Solvent extraction allows for a significant yield, potentially reaching up to 97%.

• Drawbacks : Solvent extraction requires a significant volume of solvents. Solvents are typically expensive and polluting compounds, posing a risk to the environment. They can also represent a real public health issue and have harmful effects on health, particularly on reproduction.