The difference between pressing and leaching
Different processing techniques
The processing technology of pressed oil is "physical pressing method", while the processing technology of leached oil is "chemical leaching method". The production process of the physical pressing method requires the raw materials to be carefully selected. After the soybean is removed from impurities and stones, it is crushed, steamed, fried, and squeezed to separate the oil from the soybean. During the pressing process, fried seeds are added, and after being squeezed by the press, using high-tech natural filtration and purification technology. It maintains the original taste of soybeans, has a mellow aroma, is rich in vitamin E, has a long shelf life, and does not contain any additives, solvent residues and soap content. It is a pure natural green food produced by a combination of modern technology and traditional technology. The leaching method adopts an organic solvent extraction method. The oil is fully combined with organic solvents such as "No. 6 light gasoline" (common name for "No. 6 solvent oil") and then extracted. Therefore, n-ethane and other organic substances that are toxic to the human body, which is difficult to completely remove. Only after the refining reaches very strict standards can it be safely consumed. Otherwise, it will easily cause harm to the human body. However, during high-temperature refining, some vitamin nutrients will inevitably be lost. Due to the high oil yield of the leaching method, most corn oil, soybean oil, cottonseed oil, etc. are basically processed and manufactured using the "No. 6 light gasoline" leaching method.
Different nutrients
Pressed soybean oil has complete color, aroma and taste, and retains various nutrients. Leached oil is colorless and odorless, and most of its nutrients are destroyed after processing. The edible oil standards drafted by the State Grain Administration have been introduced and implemented, canceling the Chinese edible oil standards. The new standards stipulate that pressed soybean oil and extracted soybean oil must be marked with the words "pressed" and "leached" respectively on the product label. With the progress of society and the improvement of people's living standards, people's pursuit of nutrition and health has become people's pursuit. The purpose of making the soybean oil production process transparent is to let consumers understand the soybean oil production process and give consumers the right to know.
Raw material requirements are different
"Expressed soybean oil" uses a purely physical pressing method, which retains the original taste of soybeans and juice. Therefore, the requirements for soybean raw materials are very strict. The raw materials are required to be fresh, with low acid value and peroxide value, so the price is relatively high.
