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