Crude corn oil is a deep red amber vegetable oil obtained by pressing or leaching corn germ. The crude corn oil has a high impurity content and becomes turbid at low temperature and cannot be used directly.
Product Description
Crude corn oil is a deep red amber vegetable oil obtained by pressing or leaching corn germ. Crude corn oil contains phospholipids, sterols, tocopherols and other unsaponifiables, fatty acids, waxes, and has a special odor. Crude corn oil has a high impurity content and will become cloudy at low temperatures, so it cannot be used directly. After refining, corn refined oil with low cloud point, low melting point and stable storage can be obtained, which meets national standards
According to the composition and properties of impurities in corn oil, it can be divided into three categories:
(1) Insoluble solid impurities, such as sludge, cake powder, fiber, clay, catalyst, etc.
(2) Colloidal impurities, such as free fatty acids, sterols, vitamin E, pigments, vitamins, gossypol, etc.
(3) Volatile impurities, such as water, alcohols, hydrocarbon solvents, odor substances, etc.
Most impurities are harmful to the quality and storage safety of corn oil. For example, moisture will not only affect the transparency of oil, but also promote the hydrolysis and rancidity of oil; Free fatty acids affect flavor and promote deterioration; Phospholipids can cloud the oil and produce a black precipitate when heated. Various pigments directly affect the color of oil and promote the rancidity of oil.
Main process flow of corn oil refining equipment：
(1) Degumming of corn oil: the methods of hydration and acid refining are generally used to remove phospholipids, mucus, resin, protein, sugars and trace metals from crude oil.
(2) Deacidification of corn oil: free fatty acids, acid pigments, sulfides, insoluble impurities and trace metals in the oil are removed by food grade alkali neutralization method.
(3) Corn oil-water washing: wash away the soap horn and water-soluble impurities remaining in the oil during deacidification.
(4) Dehydration of corn oil: the water in refined oil is removed by heating and vacuum drying.
(5) Decolorization of corn oil: use adsorbents such as clay, aluminum silicate and activated carbon to remove various pigments, colloids and oxides in the oil.
(6) Deodorization of corn oil: the principle of vacuum stripping is used to remove low molecular odor substances, free fatty acids, glycerol monoesters, glycolipids, sulfides, thermal decomposition products of pigments, etc.
(7) Dewaxing or degreasing of corn oil: freezing, crystallization or winterization crystallization are mainly used to remove wax grease in the oil by fractionation.
