Cooking oil is a necessity in every kitchen, but most people don’t know what kind of oil they are using! Even if they do know, very few of them have a clear understanding of how cooking oil is processed.

Pressing and Leaching

Pressing: Separating the oil from the oil by applying physical pressure, this method originated from the traditional workshop method of oil production, but nowadays the pressing method is an industrialized operation. Since the pressing method does not involve the addition of any chemical substances, the various components of the extracted oil remain relatively intact, but the disadvantage is that the oil yield is low.

Leaching method: Selection of solvents in accordance with the relevant national standards, the use of fats and oils and the selected solvent miscible nature, through the solvent and the treated solid oil in the oil material in contact with the oil and fat will be extracted and dissolved out, and with a rigorous process to remove the solvent in the oil and fats.

Compared with the pressing method, less residual oil in the leaching system meal, high oil yield; low processing costs, good production conditions; oilseed resources have been fully utilized.

The process of different oilseed varieties

There are differences in the chemical composition, content and physical properties of different oilseeds. The two oil production processes, pressing method and leaching method, are applicable to different raw materials respectively.

Generally speaking, high oil content oilseeds using pressing, such as sesame, peanut, olive, rapeseed, etc.; low oil content oilseeds using direct leaching, such as soybean, rice bran, etc.; and some oilseeds can produce a special flavor of oil, in order to maintain its products do not lose the original flavor, more to take the pressing method of taking oil, such as sesame oil, peanut oil and other fats and oils production.

Pressing oil is generally after the initial deacidification and degumming on the line. The pressed oil may be more in line with the taste characteristics of Chinese people because it retains the flavor of the oil material itself (such as peanuts). Leached oil, on the other hand, undergoes deacidification, degumming, decoloration and deodorization, during which it is possible to get rid of the soybean smell that many people dislike.

Refining

Crude oil that has only been pressed or leached without refining contains more gums, free fatty acids, colored substances, etc., which cannot be consumed directly and can only be used as raw materials for finished oil products. In order to prevent harm to the health of consumers, crude oil must be refined and processed, after washing, alkali washing, deacidification, decolorization, deodorization and other processes, so that it becomes lighter in color, clarified refined oil, to meet the standards of all levels of oil products before they can be marketed and sold.

The factor that affects the quality of edible oil is not the production process, but the degree of refining and whether the production process is operated in strict accordance with the norms.

How to distinguish between pressed oil and leaching oil

1) Take a look, according to the national standard labeled on the packaging of edible oil. Note: pressed oil, does not need high temperature refining, also does not need refining process, there is no problem of chemical solvent residue;

(2) smell, pressed oil is very fragrant, such as tea oil this unique oil flavor. Leaching oil is almost colorless and tasteless;

3) Test, pressed oil does not contain antioxidants (TBHQ), retaining the original vitamin E;

4) Compare and contrast, pressed oil requires high raw materials and has a lower oil yield, which makes it more expensive.

How to look at pressed oil and leached oil?

China Vegetable Oil Industry Association Secretary General Wang Junseed that, from the safety and environmental protection, pressed oil due to the ability to maintain the original nutrients, the quality of oil is relatively pure; and leaching oil is difficult to meet the people in pursuit of food natural, environmentally friendly consumer psychology.

Shandong Peanut Research Institute of the Chinese Academy of Agricultural Sciences, breeding experts, with national outstanding contributions to the medical experts Mao Wenyue that, to judge the merits of edible oil, the production process is an important criterion.

National Institute of Food and Nutrition, National Food Quality and Safety Teaching Steering Committee member Professor Nong Shaozhuang said that the two oils have their own advantages and disadvantages, the key to edible oil is the production process is standardized, as long as it meets the national standards can be safe to eat.

Xue Yalin, a senior engineer working on the drafting of the new national edible vegetable oil standard, said: the national standard does not exclude the two processes, and the requirement to indicate the production method is mainly to protect the consumer’s right to know, so that consumers can choose according to their own preferences, in order to meet different needs. Whether it is leached oil or pressed oil, as long as it meets China’s quality standards for edible oils and fats andhealth standards, it is safe to eat.

Therefore, no matter what kind of process is adopted to produce edible oil, as long as it meets the national quality and hygiene standards, it is safe for consumption.