“Health from Food” Series | What are some tips for choosing and preserving cooking oil?

Have you ever noticed what kind of oil you use for cooking at home? Today, let's learn about the knowledge behind the selection and storage of cooking oil.

First of all, we need to understand the processing technology of edible oil. At present, the edible oil processing technology on the market can be roughly divided into: leaching process and pressing process.

The extraction process requires the addition of chemical solvents, and edible oil produced by this type of processing technology is not recommended for household consumption.

The pressing process refers to putting the raw materials into the machine and separating the oil from the raw materials by squeezing. The advantage of this production process is that it can ensure the purity of the oil, without adding chemical additives, and retain the natural nutrients in the edible oil. The disadvantages of the pressing method are low oil yield and high production costs. The pressed oil is generally divided into three grades. The first-grade pressed oil has high purity, but the nutritional value will be greatly reduced. From a health perspective, combined with cooking methods, it is recommended that ordinary families choose cold pressing and physical pressing for cooking, and choose grade 2 or 3 oil for quality grade.

Things to note when choosing cooking oil

From a health perspective, it is recommended to change the oil at home frequently. The oil change here does not refer to the brand of oil, but the type of oil. Common cooking oils are divided into vegetable oils and animal oils. Common animal oils include: lard, tallow, mutton fat, cream (butter), etc. Vegetable oils include: soybean oil, rapeseed oil, peanut oil, and sunflower oil.

Normal people can eat these types of vegetable oils in rotation. Special groups can eat different oils according to their needs. For example, vegetable oils rich in N-9 fatty acids and N3 fatty acids are more beneficial to blood lipids and cholesterol, and N-3 is more suitable for infants and pregnant mothers.

Precautions when storing cooking oil

It is recommended to consume it as soon as possible after opening, preferably within two to three months. Many people go to the supermarket to buy oil, considering the cost-effectiveness, and will choose a large barrel. But if you live alone, it is recommended to choose a small-dose package.

Cooking oil should be stored in a cool, dry place away from light. You can choose a light-proof bottle to store the oil, and store the oil in a cabinet when not in use. Be careful not to place the oil bottle near gas for convenience, as high temperature will accelerate the oxidation and deterioration of cooking oil.

The oil pot can be made of glass or safe and qualified food contact grade stainless steel. Some people use beverage bottles to hold cooking oil for convenience, which is incorrect. Beverage bottles cannot be reused, let alone used to hold cooking oil.

Pay attention to cleaning the oil can in time to avoid adding new oil to old oil. The old oil left on the oil can will accelerate the oxidation and deterioration of the new oil, so every time the oil in the oil can is used up, it must be cleaned and dried before adding new oil.

This article was scientifically reviewed by Xin Xiaowei, nutritionist and deputy director of the Nutrition Department of the Cancer Hospital, Chinese Academy of Medical Sciences.