Pure glycerin fatty acid is no odor, but different fat has varying degrees of odor, some people love, such as sesame oil and peanut oil flavor, but some are not subject to people, such as rapeseed oil and rice bran oil with the smell. Usually the fat in the band with a variety of smells collectively referred to as the "bad smell", which some of the natural, and some are in the process of oil and processing.
The main components of the oil are low molecular aldehydes, ketones, free fatty acids, unsaturated hydrocarbons, etc. For example, soybean oil odor components have been identified as acetaldehyde, hexanal, butanone, acetic acid, butyl two ketone etc. In the process of oil production and processing will produce a new smell, such as coke paste flavor, solvent, and so on. In addition, individual oil and special smell, for example, is produced in rapeseed Oil isothiocyanate sulfides such as spicy flavor.
In addition to free fatty acids in the oil, the rest of the bad smell is less, just about 0.1%. In practice experience tells us that between odors and free fatty acid exists certain relationship, when reduce the free fatty acid content, corresponding to reduce oil in a part of the odor group points. That is to say, the de odor and the de acid are closely related. Henan Huatai cereal and Oil Machinery Co., Ltd. in edible oil refining by the most advanced new deacidification off smelly, applicable to plant oil with high acid value and low content of glial deacidification deodorization. In practice, the process has the following advantages: strong acid removal ability, good thermal bleaching effect, high refining efficiency, good oil quality and so on.
Oil can not only remove the foul smell in the oil group, improve the oil smoke point, improve the flavor of edible oil, but also make the stability of oil, color and quality have improved. Because in the removal of smell and can also removal of free fatty acid, peroxide and decomposition products and some heat sensitive pigment, remove protein in rotten oil volatile decomposition, removal of small molecular weight PAHs and pesticide residues, to drop to a safe range. So the edible oil refining need deodorization section.