This is because the black goji berries are rich in anthocyanins, it is a water-soluble pigment, usually present in the vesicles of plant cells, when the cells are broken this pigment will be dissolved into the water.

Anthocyanin-like pigment has a special property: it turns red when it meets acid and blue when it meets alkali. For example, adding appropriate amount of vinegar to the water in which the black goji berries are soaked, the color will become deep pink, and if a certain amount of alkali or baking powder is added, the color will become blue-violet again.

In addition to black goji berries, blackberry, purple potatoes, strawberries, cherries, grapes, purple kale, black beans, black peanuts, black sesame, black rice, purple rice and other purple and black foods are also rich in anthocyanins.

So it is normal for the water in which these foods are soaked to turn purple or light black. Eggplant anthocyanins only exist in the skin, and the skin has a layer of transparent epidermal cells to protect, so normal rinsing will not lose color.

Purple-black food and anthocyanin content, soaking water temperature and other factors, the higher the temperature of the water, the faster the pigment dissolved, such as black peanuts soaked in cold water, about 1 minute will dissolve out of the pigment; into the 60 ℃ hot water in just a few seconds can be a cup of water dyed purple-black.

Extended information

Drinking black goji berries:

1, in the brewing of black goji berries, be sure to control the amount, do not brew too thick, but also can not be often a large number of black goji tea. If you overdose on black wolfberry, it is likely to cause swelling and pain in both eyes, and the vision will get worse and worse.

2, black wolfberry is also has certain eating contraindications crowd, is not suitable for all people to eat, some of the patients with yin deficiency or spleen and stomach is weak, and cold and fever and body inflammation, is not suitable to eat black wolfberry, especially with high blood pressure and temperament is too impatient people, more unsuitable for eating black wolfberries, otherwise it will give the body a serious harm.

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