When eating apples, you peel them; when cooking tomatoes, you skin them; when eating grapes, you spit out the skins; when stewing winter melon, you peel it... How many similar habits do you have? Little do you know that while enjoying the good taste, you may be losing many valuable nutrients.
Antioxidants
Whether it's polyphenolic substances like anthocyanins and flavonoids, or vitamin C, they all have powerful antioxidant effects. They can resist damage to the human body from free radicals, prevent cardiovascular diseases, and improve the body's immunity. The content of these nutrients in the peel may be greater than in the pulp. For example, the main components of mung bean cotyledons are protein and starch, while the skin contains a large amount of antioxidant components such as flavonoids, tannins, and saponins; eggplant skin concentrates most of the anthocyanins and flavonoids; grape skin not only contains a large number of antioxidants but also contains resveratrol, which has the effects of lowering blood lipids, anti-thrombosis, and preventing arteriosclerosis; apple skin is rich in vitamin C, anthocyanins, and other polyphenolic substances. In addition, black bean skin, red bean skin, kidney bean skin, and peanut red skin also contain a large number of antioxidant components.
Cancer-preventing and anti-cancer components
The pungent radish skin contains a considerable amount of isothiocyanates, which is the key component in radish's anti-cancer effect; lycopene, which is abundant in tomato skin, is one of the most powerful natural antioxidants discovered so far, capable of preventing cardiovascular diseases and cancer.
Other nutrients such as dietary fiber
The skins of most fruits, vegetables, and grains are rich in dietary fiber, which can promote intestinal peristalsis and help prevent constipation, such as apple skin, tomato skin, grape skin, and red bean skin. At the same time, the skin is also a place with a high content of minerals and vitamins. For example, eggplant skin contains vitamin P and B vitamins, pear skin is rich in iron and zinc, and the chromium content in apple skin is much higher than in the pulp. From the perspective of Traditional Chinese Medicine, some skins also have special effects. For example, winter melon skin has the effects of relieving summer heat, strengthening the spleen, and promoting diuresis.
It is recommended that when eating the above foods, try to eat them with the skin on. To reduce pesticide residues, it is best to scrub fruits and vegetables vigorously under the faucet. Fruits and vegetables with a "tough" exterior can also be scrubbed with a small brush. Once you feel they are clean, rinse them with water for another 15 to 20 seconds before eating with peace of mind. Soaking in tap water can also remove some pesticide residues, but do not soak for too long, 10 minutes is appropriate. Polyphenolic substances are unstable under alkaline conditions, so when making porridge with miscellaneous grains like mung beans, you should not add baking soda.
Finally, it needs to be reminded that not all food skins are edible. Potato skin contains toxic solanine; during the growth process of sweet potatoes, harmful substances may accumulate in the skin; water chestnut skin may have absorbed many harmful biological excretions and may also contain parasites; the skin of ripe persimmons contains a large amount of tannic acid. These skins should not be eaten.