1, the principle is different
Squeezing is to separate oil directly from oil by physical pressure, and there is no chemical additive in the whole process, which ensures that the product is safe, hygienic, pollution-free and natural nutrition is not destroyed.
Leaching is to use the mutual solubility of oil and organic solvent to squeeze the oil into embryo slices or puffs, and then contact the embryo slices with organic solvents such as n-hexane in a device called an extractor to extract and dissolve the oil.
2. Different methods
The pressing method adopts the pure physical pressing technology to make oil, and after material selection, baking and physical pressing, it is finally produced by natural plant fiber filtration technology.
Leaching method is to fully soak the oil and fat raw materials with solvent oil (No.6 light gasoline), then leach at high temperature, and then go through the "six-removal" process (i.e. degreasing, degumming, dehydration, decoloration, deodorization and deacidification).
3. Different characteristics
Squeezing method does not involve adding chemicals, retains rich nutrition in oil, has no chemical solvent pollution, and does not contain any chemical preservatives and antioxidants. But the oil yield is low and relatively low.
Leaching method has high oil yield and low production cost, which is one of the reasons why the price of soybean salad oil is generally lower than that of pressed oil. But in the process of leaching, the residue in edible oil is inevitable.
Extended data:
Two methods of squeezing edible oil:
1, hot pressing
After crushing and heat treatment, the raw materials can passivate the activity of enzymes, inhibit the proliferation of microorganisms and ensure the quality of juice. This technology is mainly suitable for juicing drupes and berries. In addition, in the production of red grape juice, in order to improve the extraction rate of pigment, hot pressing is generally used.
2. Cold pressing
Cold pressing refers to squeezing juice at or below room temperature without heat treatment after raw materials are crushed. For example, apples with drupe are generally cold pressed. Cold pressing helps to maintain the natural color of fruits and improve the stability of products. The purpose of making oil by cold pressing technology is to avoid overheating and excessive chemical treatment of oil, and to improve the quality of refined oil and cake accordingly.
References:
Baidu encyclopedia: squeezing method
References:
Baidu encyclopedia: leaching method