Soy oil is rich in linoleic acid. Linoleic acid has limited effect on reducing the risk of heart disease. As linoleic acid is not heat-resistant, it is easy to oxidize and polymerize after frying or repeated heat, which is very harmful to health.
Press method is divided into two: general press method and screw press method. The common press method is now rarely used, especially in industrial mass production. The screw press method is relatively complex. The cylinder of the horizontal device is installed with a spiral shaft. After the pre-treated soybean enters in soya bean oil extraction machine, the oil is squeezed out as it advances. Continuous production can be realized in this way. But in the process of oil extraction, because of friction and heat, the protein is mostly changed to a greater extent.
Soybean oil from soybean oil expeller is commonly known as soybean salad oil and is one of the most commonly used cooking oils. Soybean oil is pressed from soybeans, including cold-pressed soybean oil from the cold press and hot pressed soybean oil from the hot one. The color of cold-pressed soybean oil is shallow, raw bean taste is weak. Due to the high-temperature treatment of the raw material, the oil yield is high, but the color is dark and has a strong smell of raw beans. Like rapeseed, soybean oil press can increase oil yield by slightly improving the press method.
1. High degree of unsaturation;
2. Liquid state at room temperature;
3. It can be selectively hydrogenated and used for blending with semisolid lipids or liquid oils.
The soybean oil cake extracted by the soybean oil machine can be used to make tofu. It can also be boiled to make soy milk.