Although overnight green tea is not absolutely harmful, it is better to drink less, especially the deteriorated overnight green tea. Overnight green tea, in the old days, the container was not well sealed, which would cause poisonous insects to fall into or climb over. protein and sugar in the soup became nutrients for bacteria and molds. Because of too long time, most vitamins have been lost, so it is not suitable for drinking. There is no scientific basis for overnight tea to cause cancer.

It is not recommended to keep green tea for too long, because the nutrients such as tea polyphenols, amino acids and tea polysaccharides in green tea will slowly ooze out within 1 hour. If it takes too long, these nutrients will be lost.

Overnight tea will produce tea polyphenols, which will darken the color of tea leaves after oxidation, and then form tea rust on tea sets, which is also bad for people's health.

In addition, overnight tea also has the problem of nitrite, which is similar to overnight meal. However, the content of nitrite in tea is too low to affect people's health. When tea leaves are left for a long time, some shiny things will be produced on the surface, not heavy metals, but polyphenols after oxidation.

Extended data

Overnight tea may be harmful to your health.

1. Tea contains tea polyphenols, which are easily oxidized into brown colloid-tea rust in air and water. Tea rust contains many substances such as cadmium, lead, iron, arsenic and mercury.

The tea leaves that have not been drunk or left in the cup for a long time, such as overnight tea, are exposed to the air for a longer time, and the more tea polyphenols are oxidized into tea rust. Tea rust enters the human body, combines with protein, fat and vitamins in food, and precipitates, which hinders the absorption and digestion of nutrients.

2. Once these oxidants enter the human body, they will also cause inflammation, ulcer, necrosis and other diseases in organs such as kidney, liver and stomach. Therefore, overnight tea should not be drunk, and tea sets should be scrubbed frequently.

3, the summer temperature is high, tea is easy to rancidity and taste, if put on hold for more than 24 hours, it is best not to drink, otherwise it will cause diarrhea.

4, overnight tea because of too long time, most of the vitamins have been lost, as well as protein, sugar and so on. Tea is not suitable for drinking because it contains nutrients that can breed bacteria and molds.

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Baidu encyclopedia-overnight tea