1.According to the source of raw materials, it can be divided into animal oil, vegetable oil and microbial oil.Animal oil refers to the oil obtained from animals, such as beef oil, pig oil, fish oil, etc .Vegetable oil from plant roots, stems, leaves, fruits, flowers or seeds tissue processing and extraction of oil, such as soybean oil, rapeseed oil, cottonseed oil, peanut oil, sesame oil, rice bran oil, sunflower oil, corn oil, tea seed oil, flax seed oil, safflower seed oil, etc. Microbial oil, also known as single-cell lipids, refer to edible fats extracted and processed from certain microorganisms, including yeast, fungi and algae.
2. According to the processing technology,:it can be divided into pressing oil and leaching oil.According to the processing temperature of billet, pressing oil can be divided into cold pressing oil and hot pressing oil.Cold oil refers to the raw material without steaming and frying, such as high temperature treatment,it is press directly after cleaning up, and the oil temperature at 60 ℃ (or below 70 ℃) ..Hot pressing oil refers to the material blank after high temperature steaming and stir-frying and then pressing.The advantages of the press method are that the product is less polluted and the nutrients are not easily damaged, but the disadvantages are low oil yield and high cost.Oil leaching refers to the extraction of oil from oil with edible organic solvent. Leaching has been desolventizing, degummed , deaciddification, decoloring, deodorization, according to the product quality grades, adopt different refining processes) after processing of refined oil products and its advantage is high yield efficiency, low processing cost, the disadvantage is that MAO oil residue.
3. According to the new national standard of products can be divided into first grade oil, second grade oil, third grade oil and fourth grade oil.The grade of the product is only different in the degree of refining. Generally speaking, the refined grade of the oilfrom crude oil is the different refining process .No matter level 1 or 4 edible oil, as long as it is accordance with national standard , consumer can be at ease edible.
4. According to Degree of unsaturation :some oils will form a layer of elastic, hard, solid film when placed the in the air. a phenomenon called lipid desiccation. According to different degree of all kinds of oil drying, the grease can be divided into drying oil, (tung oil, linseed oil), semi-dry oil (sunflower oil, cottonseed oil) and non-drying oil ( peanut oil, castor oil) .Dry oil, iodine value greater than 130;Semi-dry oil with iodine value of 100 ~ 130;Non-drying oil, iodine value less than 100.
