Nutritional characteristics of salad oil
The word salad oil originated from the west, as the name suggests, it is a special oil for salad; Salad is a cold salad with raw vegetables as the main ingredient, supplemented by various condiments. In order to increase nutrition, you need to apply an oily coating, which is salad oil. In order to maintain the inherent color and taste of vegetables, this oil needs to be colorless and tasteless; And cold dishes often need to be refrigerated after they are cooked. Therefore, turbidity cannot occur at low temperature, and it must be kept in a transparent liquid state at 4.4℃. Therefore, salad oil needs to remove non-triglyceride components from plant crude oil as much as possible, and generally it can only be vegetable oil.
Edible oil, also known as cooking oil, can be vegetable oil or animal oil (vegetable oil here). Edible oil should be liquid at room temperature, with good fluidity, rich in nutrients inherent in oil and no unpleasant smell. Technically, it's not the same as frying oil. The main feature of frying oil is that it is not easy to deteriorate at high temperature for a long time (160℃- 180℃), that is, it does not undergo thermal oxidation and hydrolysis.
In Europe and America, edible oil and frying oil belong to the range of shortening with different physical properties, while salad oil refers to liquid cold oil. In Japan, edible oil, salad oil, frying oil, etc. , has a strong specificity, their characteristics are also very different.
According to national standards, there are edible first-class oil, second-class oil, advanced edible oil and salad oil. As far as the consumption level in most areas is concerned, there is no distinction between edible oil and salad oil. In most areas, edible oil is mainly used for cooking, that is, cooking, so it is mainly edible oil. In recent years, with the introduction of oil refining production lines and the continuous maturity of domestic oil refining equipment, the output of salad oil and refined oil products of various enterprise standards has been continuously improved, coupled with the advertising effect of some manufacturers, the consumption of edible oil in some cities and regions has gradually turned to salad oil and other refined oil products, which shows that people's consumption level has improved and they are pursuing more refined and pure food. However, from the nutritional point of view, whether salad oil is suitable for cooking oil is worth discussing.
From a chemical point of view, more than 95% of the existing natural oils and fats are composed of fatty acid triglycerides with different degrees of saturation and unsaturation, accompanied by a small amount of various lipids. These lipids mainly include phospholipids, free fatty acids, sterols and sterol esters, vitamins, pigments, terpenes, waxes, fatty alcohols, hydrocarbons and so on. Most of them are beneficial and harmless to human body, but there are still some components and some oils containing toxic components that must be removed. From crude oil to salad oil, degumming (dephosphorization), deacidification, decoloration and deodorization are usually needed, and some oil products need dewaxing. After these refining processes, a series of changes will take place in the contents of main lipid components and nutrients in oil.
Although vegetable oil is not very fragrant, it is nutritious and healthy.
Waste oil is generally only used in some roadside stalls and unlicensed small restaurants. The cooked food not only tastes much worse, but also is harmful to human body. Never use them.