All components other than triglycerides in oils and fats are called impurities. The purpose of refining is to remove impurities, maintain the biological properties of the oil, and retain or extract useful substances.groundnut oil pressing machine
In fact, refining does not remove all impurities, but selectively removes impurities. According to the composition and nature of impurities in crude oil, hand operated oil press they can be divided into three categories:
1. Insoluble solid impurities, such as sand, cake powder, fiber, etc., clay, catalyst, etc.
2. Peptide-soluble impurities, such as FFA, vitamin E, pigments, vitamins, gossypol, etc.
3. Volatile impurities: such as moisture, odorous substances, etc.
Most impurities are detrimental to oil quality and storage safety. For example, moisture not only affects the transparency of oil but also promotes the hydrolysis and rancidity of oil. savaliya cold press oil machine Insoluble impurities and acidic substances are both promoting factors of oil deterioration. FFA affects flavor and promotes deterioration. Phospholipids can make oil cloudy, and when heated, it will produce black deposits, bubbles, bitterness, etc.napa valley sesame oil
Various pigments directly affect the color of the oil, and some also promote the rancidity of the oil. There are also some useful “impurities” in crude oil, such as tocopherol, oryzanol, etc. It is not only a natural antioxidant for oils, but also beneficial to the human body. wood pressed peanut oil It is allowed to be retained during refining, and it can also be extracted for use. Phospholipids are a class of “impurities” that must be extracted and have a high utilization price.moringa seed oil extraction machine