Tea is the most popular beverage worldwide. About 3.5 million tons of tea are produced each year. This information applies only to tea of the tea bushes Camellia sinensis and Camellia assamica. The per capita consumption in Germany is 25 liters. The love of tea is regionally very different. The highest consumption in Germany has the East Frisians. They drink about 10 times as much tea as the rest of the Republic. But also in the world they take third place - after the Irish and Libyans - a leading position.
Incidentally, according to food law, the simple term "tea" on packs may only be used for black tea or green tea. The other plants or plant parts that give a drink with hot water are listed under the category "tea-like products".
What is in the tea?
The most important ingredients of tea include caffeine. The content in tea leaves is between 0.9 and 5 percent, depending on the type of tea. So with a cup of tea (150ml) you take 20 to 56 mg of caffeine. Compared to other caffeinated drinks, the effect of caffeine in tea slows down and lasts longer because the released caffeine is bound to tannins.
The caffeine content of green and black tea is about the same size. Some green tea varieties even contain more caffeine than black tea. How much caffeine goes into the freshly brewed tea, however, depends largely on the water temperature, with which the tea leaves are brewed. Since green tea is not brewed in the same way as black tea with boiling water, the caffeine content of green tea in infusion is generally lower.
The tannins (polyphenols) are contained in tea leaves to about 10 to 20 percent. You are awarded numerous health benefits. The most important representative is the EGCG (epigallocatechin gallate). Both black and green and white tea are good suppliers of healthy polyphenols. Tea also contains essential minerals and vitamins. In addition to fluorides, which are important as caries protection, tea provides iron, zinc, vitamins A, E, C and numerous B vitamins.
Black, green or white?
The Germans still prefer black tea. He accounts for 77 percent. But green tea is becoming increasingly popular, which currently accounts for 23 percent of total consumption. These are not two different tea plants. Green and black tea are made from the same leaf material. Only post-harvest processing takes place in different ways.
- Black tea
Black tea is subjected to so-called fermentation after wilting and rolling. In this process, the polyphenols contained in the tea leaves (catechins and catechin derivatives) are converted into theaflavins and thearubigenes by leaf-own enzymes, the so-called phenol oxidases. The tea changes its color and develops its characteristic aroma by the connection of the cell juice with oxygen.
- Green tea
Green tea differs from black tea only in that it is not fermented. After wilting, the picked leaves are steamed. By treatment with dry heat or steam, the phenol oxidases are inactivated, ie the catechins contained in the tea are not oxidized and the green chlorophyll is retained. Accordingly, the content of polyphenols (tannins) in green tea is higher than in black tea.
- White tea
White tea is characterized by the special selection of tea leaves. Only the unopened leaf buds of the tea bush cultivated in Fujian Province, southern China, are used. The mild taste of this type of tea is due to the gentle drying of light and air. As a rule, white tea is a slightly anfermented tea, whereby the fermentation process takes place naturally during the wilting process.