Unrefined oil is usually of light brown or brown color with cloudiness or lees. It has a clear taste of sunflower seeds and is used to season salads. Unrefined vegetable oil contains some undesirable components found in oilseeds: waxes, pigments, heavy metals, radionuclides, pesticides, etc. That is why refining (or purification) is a necessary technological process. Refining consists of the following steps:
- Mechanical cleaning – removal of impurities
- Hydration – the process of phospholipids removal
- Whitening – the process of sunflower oil clarification using activated bleaching clays of natural origin
- Freezing – removal of wax-like substances (waxes) by prolonged cooling of the oil followed by filtration
- Deodorization – removal of oxidation products (free fatty acids and peroxides) and odorizing (flavoring) substances from oil using high temperatures under vacuum.
Sunflower oil (brand P)
Refined deodorized freezed out sunflower oil of brand P
- Color number, mg of iodine, – no more than 10;
- Acid number, mg KOH/g, – no more than 0.4;
- Mass fraction of phosphorus-containing substances, % in terms of stearooleolecithin – absent;
- Mass fraction of moisture and volatile substances, % – no more than 0.10;
- Mass fraction of non-fatty impurities, % – absent;
- Peroxide value, mol/kg – no more than 5.0.