In the eyes of many, stir-frying is not a difficult task; you just heat the oil and stir in the vegetables. I would like to remind everyone that for the following vegetables, it is best to blanch them before stir-frying.
Vegetables high in oxalic acid, such as amaranth and spinach. Excessive intake of oxalic acid can affect the body's absorption of minerals like calcium and zinc, and it also increases the risk of kidney stones. Generally, vegetables with a slightly astringent taste, such as spinach, amaranth, water bamboo, and bamboo shoots, contain relatively high levels of oxalic acid. Studies have shown that for vegetables like spinach and amaranth, blanching in boiling water for a short time can remove 40% to 70% of the oxalic acid.
Toon (Chinese toon). Toon contains relatively high levels of nitrates and nitrites, which can potentially form carcinogens in the body. However, blanching toon in hot water for about one minute can remove more than two-thirds of the nitrites and nitrates. Therefore, it is best to blanch toon before cooking.
Wood ear mushrooms. Stir-frying wood ear mushrooms can easily cause them to splatter, but this problem can be avoided by blanching them in boiling water first. When soaked, wood ear mushrooms absorb a lot of water, and blanching helps to expel this moisture. Therefore, they are less likely to splatter when stir-fried. It should be noted that wood ear mushrooms are curly with many "small grooves." After blanching, drain them in a colander and then give the colander a few extra shakes to ensure all the water is removed.
Tofu. Tofu is quite soft and tender, and it can easily break during cooking. Blanching it in water before adding it to the wok not only helps to remove the beany flavor but also makes the tofu firmer, so it is less likely to crumble when cooked.
Wild vegetables such as purslane and shepherd's purse. Wild vegetables may carry risks of pesticide residue or contamination from wastewater and exhaust gases. To reduce these risks, they must always be blanched before cooking.