Colloidal structures in natural oils

Natural oils are in general mixtures of triglycerides of various fatty acids containing also small quantities of a multitude of other molecules, the minor components. Their composition depends on the type of their sources, either vegetable or animal, and on agronomic and climatic conditions. Extraction process highly influences the final composition of the natural oils. The bulk triglyceride phase presents some structural order due to the internal polarity of these molecules. The presence of the minor components, which are either amphiphilic or even hydrophilic together with some remaining moisture, induces colloidal association within the lipophilic triglyceride phase. These local organizates host proteins and antioxidants that preserve their activity influencing the quality and stability of the edible oils. Of specific interest is the case of the veiled virgin olive oil, the untreated juice of the olives. Veiled virgin olive oil is unique among vegetable oils that is consumed without any refining process and consequently possesses colloidal structure. It is remarkable that this unfiltered oil presents higher resistance to oxidation than the filtered ones, indicating the significance of internal structure to the final quality of the product.