Soybean oil from soybean seed, soybean oil is the world's largest production of the oil. Many different kinds of soybean oil, according to processing methods can be divided into crushing leaching soybean oil, soybean oil, According to the types of soybean can be divided into soybean oil, transgenic soybean oil. Look from nutritional value, 7-10% soybean oil contains palmitic acid, stearic acid, 2-5% arachidic acid 1-3%, 22-30% oleic acid, linoleic acid, 50 to 60, linoleic acid 5-9%. Soybean oil fatty acid composition is good, it is rich in linoleic acid, significantly reduce serum cholesterol, prevent cardiovascular disease, soy also contains rich amount of vitamin E, vitamin D and more lecithin, are very beneficial to human body health. In addition, human digestion absorption rate is as high as 98% soybean oil, soybean oil so good cooking oil also is one kind of high nutritional value. 

 

The national standard GB 1535-2003 "soybean oil soybean oil in accordance with the quality can be divided into 4 class. When consumer choose and buy soybean oil, can know the kinds of soybean oil from the label (pressing or leaching), quality grade, etc. Using transgenic soybean producing oil in its marked on the label "genetically modified soybean oil" or "raw materials for processing of transgenic soybeans". In 2004, our country began to implement the system of food safety market access, sales should have the QS logo for all kinds of soybean oil. The compositions of soybean oil Soybean oil fatty acid composition content (%) content (%) of palmitic acid oleic acid 25 to 36 6-8 stearic acid 3-5 arachidic acid linoleic acid 52-65 linolenic acid 0.4 0.1 0.4 0.1 contains a large amount of linoleic acid in soybean oil. Linoleic acid is human body essential fatty acids, which have important physiological functions. Children's lack of linoleic acid, the skin becomes dry, scaly thickening, slow growth and development; Old people lack of linoleic acid, can cause cataracts and heart cerebrovascular disease. Soybean oil has bean smell, can remove after refining, but in the process of storage has a tendency to aftertaste. Bean smell caused by including linolenic acid, linoleic acid, linolenic acid content in choice of hydrogenated way down to the youngest, and avoid the generation of linoleic acid, can be basically eliminated "finish" phenomenon in soybean oil. Refined soybean oil in storage for a long time, the color will change from shallow to deep, this phenomenon is called "color". 

 

The color of the soybean oil recovery phenomenon significantly than other oils, oil oxidation reaction is the main cause of this one phenomenon. By using nitrogen preservation or try to isolate the oil with air to exposure can solve this problem.