When making tea in a thermos cup, the tea leaves are soaked in high temperature and constant temperature water for a long time. First, a large number of tea polyphenols, tannins, tannins, theophylline and so on. Seepage makes tea soup rich in color, bitter in taste and rich in harmful substances.
Second, vitamins and flavonoids are not resistant to high temperatures, and long-term high-temperature soaking will destroy the nutrients in them, greatly reducing the nourishing and health-care functions of tea. Third, the aromatic oil in tea will evaporate quickly, reducing the fragrance of tea.
Some tea experts suggest that tea should be soaked for 4-6 minutes before drinking. At this time, 80% of caffeine and 60% of other soluble substances have been soaked out. However, soaking in the thermos for a long time at high temperature will extract too much caffeine, theophylline and tannic acid from tea, which is too irritating to the gastrointestinal tract and is not conducive to health.
The thermos cups sold in the market have the same function, but the liner materials are different, such as ceramics, porcelain, stainless steel, plastic and so on. These materials have different chemical reactions due to different pH values. Therefore, this is also the focus of making tea in thermos cups, soaking various Chinese herbal health teas, and even brewing fruit juice, milk and so on.
In principle, Chinese herbal medicines should not be stored in metal products to avoid chemical reactions. I believe everyone has a unified understanding of this. Others, such as honey water, milk, juice, and of course tea, should also try to avoid using thermos cups with metal and plastic liners. To sum up, it is really not advisable to make tea in a thermos cup and directly make health tea.
Extended data
It is best to choose ceramic cups, glasses and enamel cups for making tea.
1. Ceramic cup: Because of its special materials and processing technology, ceramic cups hardly release harmful substances during use, so ceramic cups are the best choice for making tea.
2. Glass: Glass does not contain organic chemicals during the firing process. When people drink tea from a glass, they don't have to worry about chemicals being drunk into their stomachs.
In addition, the glass surface is smooth and easy to clean, and bacteria and dirt are not easy to breed on the cup wall. Therefore, drinking tea with a glass is relatively healthy and safe.
3. Enamel Cup: The traditional enamel cup is made of thousands of degrees of high-temperature enamel, and it does not contain harmful substances such as lead, so it can be safely used. Therefore, if you want to drink a cup of tea with strong fragrance, it is best to brew it with tea sets such as ceramic cups, glasses and enamel cups.
People's health network-health tea and thermos cup
People's Health Network-Why can't a thermos cup make tea? Reducing taste is also harmful to health.