Rapeseed oil is oil made from rapeseed after being impregnated. It is also called “vegetable oil†and is one of the varieties of edible oil in China.
Rapeseed oil is dark yellow and greenish, with an unpleasant odor and a spicy taste. It is generally treated with alkali, decolorization and deodorization before it can be consumed. The viscosity of rapeseed oil is large, the saponification value is the smallest in the semi-dry oil, and the erucic acid content is high, so that rapeseed oil can be identified.
Rapeseed oil has a certain economic value. As an edible oil, its digestive efficiency can reach 99%. In addition, the industry can also be used as an important raw material for lubricants, fire-fighting oils, metal antiseptics, and light industry.
Usually several physical constants of vegetable oil:
Specific gravity D420=0.909-0.914
Refractive index n20D=1.4710-1.4755
Viscosity E020=13.5-14.0
Freezing point =-12--10°C
Fatty Acid Freezing Point=12-18°C
After refining (degumming, deodorization, deacidification, and decolorization), vegetable oil is a colorless, odorless, odorless, neutral liquid that is non-volatile and can dissolve certain organic and fat-soluble vitamins. Vegetable oil is a triglyceride composed of various fatty acids. According to analysis, the average composition of various types of rapeseed oil and acid in China is: palmitic acid 2.57%, oleic acid 15.79%, linoleic acid 14.57%, linolenic acid 9.18%, eicosapentaic acid 9.41%, erucic acid 48.37% . Oleic acid and linoleic acid are beneficial to the human body. Linoleic acid is beneficial to lowering serum cholesterol and is a component of the cell membrane. It plays an important role in the development and wound healing of newborn infants. Linolenic acid contains three double bonds of unsaturated fatty acids, which are easily oxidized to produce aldehydes and ketones and produce odors, which are not suitable for food processing. Erucic acid is a long-chain fatty acid of docosacarb. The body's absorption of erucic acid is slow, and its utilization is low. Without erucic acid or low erucic acid vegetable oil, the content of oleic acid and linoleic acid is significantly increased, and the refined vegetable oil passes through. Deep processing can be made salad oil, shortening, margarine, etc., widely used in the food industry.
The erucic acid in rapeseed oil has a special industrial application. High erucic acid vegetable oil is a good lubricating oil for the cast steel industry. In addition, vegetable oil is also widely used in machinery, rubber, chemical, paint, textile, soap making and pharmaceutical industries.