Cooking stir-fry is a cooking skill that most people have to some extent, but did you know that there is actually a lot to it? Incorrect stir-frying methods can greatly reduce the nutritional value of the vegetables and may even produce carcinogens.
1. Stir-frying without cleaning the wok afterwards
Many people, in order to save time or because the wok appears clean, tend to stir-fry the next dish immediately after finishing the first one. However, the seemingly clean surface of the wok can still have oil and food residue, which may produce carcinogens such as benzopyrene when heated at high temperatures again. Therefore, it is recommended that everyone thoroughly clean the wok after each stir-fry before starting the next one. This not only reduces the production of harmful substances but also prevents the seasoning and residue from the previous dish from affecting the taste and appearance of the next one.
2. Immediately turning off the range hood after stir-frying
During the stir-frying process, a large amount of harmful substances are produced, and the range hood plays a very important role in removing exhaust fumes. Some people like to turn off the range hood immediately after finishing stir-frying. In fact, it takes time for the range hood to remove the exhaust fumes, and there may still be residue in the kitchen after stir-frying. After stir-frying, it is a good idea to let the range hood continue to run for 3-5 minutes to ensure that harmful gases are completely expelled. In addition, it is advisable to close the kitchen door and open the windows while stir-frying, as this can also reduce the residual harmful substances in the kitchen to some extent.
3. Adding ingredients to hot oil that is smoking
When the oil in the wok is smoking, the temperature is often already above 200°C. If the ingredients are added to the hot oil at this point, it increases the risk of carcinogens. Under these conditions, many nutrients in the vegetables are also destroyed. In addition, at this temperature, the oil not only destroys the fat-soluble vitamins it contains, but also oxidizes the essential fatty acids in the body, reducing the nutritional value of the oil. When cooking, it is advisable to control the oil temperature to around 150°C-180°C. The simplest method is to insert a bamboo skewer into the oil, and when many small bubbles appear around it, it indicates that the temperature is hot enough to start stir-frying.
4. Reusing oil used for frying
Many people are reluctant to throw away the oil used for frying and will continue to use it for high-temperature stir-frying or deep-frying. However, this practice is highly discouraged because heating the oil at high temperatures produces trans fatty acids and toxic lipid oxidation products. When this type of oil is used for high-temperature cooking, the production of carcinogens increases dramatically. Such oil should be avoided for high-temperature heating and can be used for stewing or making pastries such as buns.
The above information about the carcinogenic effects of cooking fumes is hoped to be helpful to health-conscious individuals.
