Did you know? Even if you always choose nutritious ingredients, if the cooking method is unreasonable, the nutrients can sneak away. Here are 9 ways of eating that are "mysterious thieves" that steal nutrients.
Peeling all fruits and vegetables
Many people are afraid of pesticide residues on the skins of vegetables and will usually peel them before cooking, such as eggplant skin, zucchini skin, radish skin, etc.
In fact, the skins of vegetables contain a variety of nutrients such as dietary fiber, vitamins, chlorophyll, minerals, and antioxidants. Peeling them before eating actually discards many nutrients.
To reduce pesticide residues, it's best to scrub the fruits and vegetables vigorously under the faucet first. For "firm" melons and fruits, a small brush can also be used for washing. Once you feel they are clean, rinse them with water for another 15-20 seconds before eating. Soaking in tap water can also remove some pesticide residues, but don't soak for too long; about 10 minutes is appropriate.
Cutting vegetables before washing
Many people, for convenience, cut the vegetables first and then wash them together. However, this method causes water-soluble vitamins like B vitamins and vitamin C, as well as some minerals, to dissolve into the water, resulting in loss.
For example, many people soak shredded potatoes and eggplant directly in water after cutting. Although this prevents discoloration, a large amount of nutrients is also quietly lost. Moreover, after the vegetables are cut, rinsing them can easily push surface pesticide residues and dirt into the cut surfaces.
Therefore, the correct approach is to wash the vegetables thoroughly first, and try to drain the moisture before cutting. Also, when washing rice before steaming, do not rub it repeatedly, otherwise a large amount of B vitamins will also be lost.
Cutting too finely
As the saying goes, "one never tires of fine food," but from a nutritional perspective, vegetables are not necessarily better the more finely they are cut. Because the smaller the pieces, the larger the surface area, and the greater the contact with air and the hot pan, the more severe the nutrient loss.
Some nutrients will also be lost along with the vegetable juices. Moreover, some people are used to prepping ingredients in advance, but this can cause vitamins that are easily oxidized, such as vitamin C, vitamin E, and B vitamins, to be lost. Therefore, it's best to cut and fry vegetables immediately, and eat them right after cooking.
Blanching vegetables for too long
Some vegetables need to be blanched in boiling water after being cut, which can remove oxalic acid and even residual pesticides, and ensure all ingredients cook evenly. However, if there is too little water in the pot or the heat is too low, the blanching time will be extended, causing a significant loss of nutrients in the vegetables.
The solution is to use as much water as possible when blanching, turn the heat to maximum, and shorten the blanching time. In general, the vegetables can be removed as soon as their color changes slightly. You can also add a few drops of oil to the water to "seal" the cut surfaces of the vegetables and prevent oxidative loss.
Randomly using alkali to marinate meat
Many people like to use alkaline substances like baking soda and tenderizing powder to marinate meat to make it more tender and smooth. However, these alkaline substances can denature proteins, making them difficult for the human body to absorb; when fat meets alkali, a saponification reaction occurs, which not only robs it of its nutritional value but also produces an unpleasant odor. Moreover, a large amount of B vitamins in the meat will be completely lost.
When marinating meat normally, you can use salt, pepper, Shaoxing wine, egg white, and starch to coat the meat slices evenly, and then pan-fry them at an appropriate temperature. This can well preserve the nutrients and also results in a good texture.
Pre-frying ingredients in oil
When making dishes like Di San Xian (braised potatoes, eggplant, and green peppers) or dry-fried green beans, many people like to first quickly fry the ingredients in oil, remove them, and then stir-fry them. This makes the dish look bright and smell fragrant.
However, this cooking method not only destroys the original nutrients in the vegetables, losing the originally rich vitamins, but the meat that has been pre-fried is also difficult to digest and can lead to excessive intake of oil.
Therefore, when cooking at home, it's best to skip this step and choose more cooking methods like blanching, stir-frying with little oil, cold salads, and steaming.
Using too high a cooking oil temperature
When stir-frying, many people like to heat the oil until it smokes before adding green onions and ginger to create a fragrant base. But by then, the oil temperature is often over 200°C. At this high temperature, vitamin E, phospholipids, unsaturated fatty acids, and other nutrients in the oil are easily oxidized, and other nutrients in the vegetables are also destroyed.
In addition, when stir-frying, if the heat is too low and the cooking time is too long, a large amount of nutrients in the ingredients, such as vitamin C, anthocyanins, and chlorophyll, will be lost with the juices.
Therefore, it is recommended to add the ingredients to the pan before the oil starts to smoke, and use a high-heat, quick-stir-frying method to shorten the heating time.
Adding salt too early
Many people have the habit of adding too much salt or adding salt too early when stir-frying. This causes too much juice to be drawn out of the vegetables, not only causing nutrient loss but also making the dish wilt and affecting the texture.
If salt is added too early to meat, the protein will coagulate prematurely, making it difficult to digest and preventing the gamey smell from dissipating, while also preventing the umami flavor from seeping into the meat. It is recommended to add salt when the dish is about 70-80% cooked, or just before serving.
Adding vinegar to green leafy vegetables
Many people like to add a little vinegar to enhance the flavor when stir-frying. However, if too much vinegar is added to green vegetables, the color will turn brownish-yellow, whereas adding vinegar to yellow and white dishes like shredded potatoes or lotus root slices has no such effect.
This is because green vegetables contain a large amount of chlorophyll and magnesium. After adding vinegar, the hydrogen in the acetic acid will immediately replace the magnesium in the chlorophyll, and this important nutrient is "stolen." Therefore, when cooking green leafy vegetables, do not add too much vinegar; it's best not to add any at all.