Vegetable oil is made from oil-rich plant seeds, which are pretreated by cleaning, impurity removal, shelling, crushing, softening, rolling, extrusion and puffing, and then extracted by mechanical pressing or solvent leaching to obtain crude oil. The quality grade of refined vegetable oil is determined according to the variety and quality of oil plants in China and the corresponding processing technology.

According to the quality standard system of edible vegetable oil in China, the general edible vegetable oil (except olive oil and special oil) on the market can be divided into four grades: soybean oil, rapeseed oil, corn oil, extracted peanut oil and extracted tea seed oil, but only one or two grades.

peanut oil

Under general storage conditions, peanut oil will undergo the process of automatic oxidation rancidity, and the changes are as follows: the automatic oxidation process is related to the season. If stored in winter, low temperature can effectively alleviate the style of lipase and oxygen. With the change of seasons and the increase of temperature, when the temperature is 15-30℃, on the one hand, the oil will be hydrolyzed and the acid value will increase due to the action of lipolytic enzymes.

When the room temperature and storage tank temperature exceed 30℃ in summer, it will be exposed to sunlight every day if it is stored in an open-air oil tank or an open-air storage yard. In this case, environmental factors will accelerate the oxidation process of oil.