Top News Dahe Health Daily reporter Hu Bingjun correspondent Wu Yunjing
Edible oil is a necessity of people's lives, consumers in the purchase of a variety of names, inevitably dazzling, such as: soybean oil, peanut oil, olive oil, rapeseed oil, corn oil and so on. When consumers choose a certain kind of edible oil, they find that the edible oil of the same raw material also has "pressing", "leaching", "first-class", "second-level", "third-level", "fourth-level", and the price difference is also large. What exactly do these glossary terms on cooking oil labels mean?
I. "Pressing" and "Leaching"
There are generally two methods for the preparation of edible vegetable oil: pressing method and leaching method. The pressing method is a method of pressing oil from oil by physical pressing. Leaching method is a method of extracting oil from oil with an edible solvent using chemical principles.
Physical pressing relies on the enormous pressure of physical machinery to separate grease from raw materials. The pure physical pressing method integrates modern science and technology, especially in the processing process using fully enclosed, pollution-free mechanized pressure oil production technology. Its safety, hygiene, nutrition and authenticity are loved by consumers, but at a higher price.
Chemical leaching is based on the principle of similar compatibility, the pretreated oil is soaked in an organic solvent, the oil in the oil is dissolved into organic reagents, and then the organic reagents and edible oil boiling points are different, and the organic reagents are evaporated and removed, so as to obtain "hair oil". This production method has a high oil yield and low cost.
In terms of preparation methods alone, it is highly inaccurate to think that the oil produced by the leaching method is not as pure as the pressing method. Whether it is leaching oil or pressed oil, as long as it meets the quality standards and hygiene standards of edible oil in China, consumers can eat with confidence.
Second, the grading of edible vegetable oil
All kinds of oils and fats have corresponding standards, generally including "color", "odor", "transparency", "soap content", "insoluble impurities", "acid value", "peroxide value" and "solvent residue" and other items. Edible oil is divided into four grades according to the degree of compliance (the lowest level of four), and the quality standards of different levels of edible oil are different, and the higher the level, the higher the refining degree of edible oil.
The first and second grade edible oils have a high degree of refining, with the characteristics of tasteless, light color, less smoke in the oil, less impurities contained in the oil, and not easy to solidify at low temperatures. Due to the high degree of refining, although the content of harmful ingredients in primary and secondary oils is low, it also loses a lot of nutrients, such as carotene.
Grade III and GRADE IV edible oils have a low degree of refining, a deeper color, a large amount of fume during cooking, and an inherent smell and taste of oils and fats. Due to the low degree of refining, the content of impurities in tertiary and fourth-grade edible oils is high, but at the same time, some nutrients are retained.
Therefore, from the perspective of smell and taste, the first and second grade edible oils have no odor and better taste; from the perspective of nutritional composition, the third and fourth grade edible oils retain a large part of the nutritional elements, but the impurities are also more.
Third, eat blended oil
Single-variety edible oil is soybean oil, peanut oil, rapeseed oil, corn oil, olive oil, etc., and edible blended oil is based on the addition of one or more other edible oils with functional characteristics on the basis of ordinary edible oil, such as rich in vitamin E type, food fatty acid balance type, rich in essential fatty acid type, etc., with outstanding functional characteristics, high nutritional value, is a commonly used edible oil by consumers. Therefore, the long-term consumption of a single product oil in the family is also unfavorable for health, and a variety of edible oils are a good choice for eating or buying edible blending oils.
In short, no matter what kind of edible oil, as long as it meets the relevant national standards and health standards, it is a safe edible oil, and consumers can choose according to their own needs.