The Difference Between Crude Oil And Refined Oil
After the initial pressing of the oil crop, the spiral oil press is called the oil, and the oil produced after the filtration and refining of the oil is called refined oil. There is a big difference, the source through the oil press to do a more detailed explanation.
Hair oil refers to pre-refined or leached animal and vegetable oils that have not been refined. Its main component is a mixture of tri-fatty acids (commonly known as neutral oil); it also contains non-materials, collectively referred to as impurities, which can be roughly classified into four categories according to the dispersion state of impurities in fats and oils.
1. Suspended impurities: including sediment, billet, powder and other solid impurities. The presence of these impurities is beneficial to microbial activity, making the oil highly susceptible to hydrolysis and rancidity, but not edible;
2, peptized impurities: including lipids, proteins, sugars, etc., the main one is the fat, the presence of these impurities is not only easy to make the oil hydrolyzed rancidity, the appearance is turbid, and will produce a lot of foam and produce a black precipitate during cooking; The color and flavor of the fried and fried foods also lose the nutritional value of the oil itself, and it also has certain toxicity.
3, oil-soluble impurities: including free fatty acids, pigments, hydrocarbon waxes, aldehydes, ketones, etc., as well as trace metals and due to environmental pollution, mercury, polycyclic aromatic hydrocarbons, aflatoxin and so on. The presence of these impurities is very harmful to the human body, and some impurities are also carcinogenic to the human body.
4. Moisture: The moisture content in the hair oil is high, and the presence of water is very easy to cause the oil to hydrolyze and deteriorate. Refined oil refers to refined oil that is refined to the hair oil and removes harmful impurities such as food and storage from the hair oil to meet the national quality standards.
There are three ways to refine wool:
1. Mechanical method: including precipitation, filtration, centrifugal separation, mainly used to separate some of the peptized impurities of mechanical impurities suspended in the oil;
2, chemical method: mainly includes acid refining, alkali refining, in addition, there are also lipidation, oxidation, etc., acid refining is treated with acid, mainly to remove pigments, peptized impurities, alkali refining is treated with alkali, mainly to remove free fatty acids, Oxidation is mainly used for decolorization.
3, physical and chemical methods: mainly include hydration, decolorization, steam distillation, etc., hydration mainly removes fat, decolorization mainly removes pigments, steam distillation for the removal of odorous substances and free fatty acids. The oil is refined through refining. The moisture, impurities, acid value and peroxide value of the oil meet the national quality standards, and it is not easy to be rancid and deteriorated. It is advantageous for storage, does not produce a large amount of fumes during cooking, and maintains the flavor of oil.
