Discoloration of food is not uncommon. For example, purple cabbage turns dark gray-blue when fried, green leafy vegetables turn olive green when cooled, and the beautiful pink of tomato dried noodles disappears after a long time. The discoloration of these foods just illustrates the fact that the colors of these foods are natural, not the result of artificial dyeing, and have nothing to do with fertilizers and pesticides.
There are also flavonoids in some light-colored foods, which will be transformed into chalcone structure under alkaline conditions, and the color is obvious. Apples and onions turn yellow after boiling, steamed bread turns yellow after boiling with alkali, and zongzi turns yellow after boiling with alkali, all of which are caused by this principle. Alkaline conditions will destroy some B vitamins, but discoloration is completely harmless to people.
Extended data:
People who are suitable for eating yam:
1, people who plan to take supplements in winter: Eating yam before taking supplements in autumn and winter is more conducive to the absorption of supplements. Yam is a tonic medicine, which has the function of strengthening the spleen and stomach, and is especially suitable for people with weak spleen and stomach to eat before tonic. It is a good choice to cook 20 grams of yam, jujube and rice (half of japonica rice and half of glutinous rice) into porridge.
2, people who plan to lose weight: Yam is a good helper to lose weight, because yam contains less calories, more nutrients, and is rich in crude fiber, which is easy to increase people's satiety and control their desire to eat. Moreover, the fat content of yam is very low, with only 0.2g fat per100g yam, thus achieving the purpose of slimming.
3. Women with cold hands and feet: Chinese medicine believes that cold hands and feet are closely related to physical weakness, while yam black chicken soup and longan yam soup have good effects of tonifying the middle warmer, benefiting qi and nourishing blood, especially suitable for patients with cold hands and feet.
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