Caffeine, with the chemical formula C8H10N4O2, is a xanthine alkaloid compound that is a central nervous system stimulant that temporarily wards off drowsiness and restores energy. It is used clinically to treat neurasthenia and coma recovery. Coffee, tea, soft drinks, and energy beverages these caffeine-containing drinks are very popular. As a result, caffeine is also the most commonly used psychotropic drug in the world.
In North America, 90% of adults use caffeine every day. Many natural sources of caffeine also contain a variety of other xanthine alkaloids, including cardiotonic agents theophylline and theobromine, as well as other substances such as tannins.
Caffeine is a plant alkaloid that can be found in many plants. It can paralyze insects that eat plants containing caffeine as a natural insecticide. The caffeinated plants most usually used by people include coffee, cocoa, and tea. Other less frequently used Paraguayan wintergreens and guarana trees are commonly used to make tea or energy drinks. The two aliases of caffeine, Mandarin and Guarana factor, evolved from these two plants.
The most important source of caffeine in the world is the coffee bean (the seed of the coffee tree), which is also the raw material for coffee. The amount of caffeine in coffee depends greatly on the type of bean and how the coffee is made, and even the caffeine content of beans from the same tree varies greatly. In general, the caffeine content in a cup of coffee ranges from 40 mg in Arabica espresso to 100 mg in espresso. Deep roasted coffees are generally lower in caffeine than lightly roasted coffees because roasting reduces the amount of caffeine in the beans. Arabica coffee usually has a lower caffeine content than medium-fruit coffee. Coffee also contains traces of theophylline, but no theobromine.
Tea is another important source of caffeine. The caffeine content of each cup of tea is generally only half of that of each cup of coffee, which depends on the strength of the tea. Certain types of tea, such as black tea and oolong tea, have higher caffeine content than other teas. Compared with coffee, in addition to caffeine, tea also contains a small amount of theobromine and a slightly higher theophylline. The production of tea has a great influence on tea, but the color of tea can hardly indicate the content of caffeine. The caffeine content of Japanese green tea is much lower than many black teas, such as Lapsang Souchong tea, which contains almost no caffeine.
Chocolate made from cocoa powder also contains a small amount of caffeine. Chocolate is a very weak stimulant, mainly due to the theobromine and theophylline contained in it. A typical piece of 28 grams of milk chocolate has the same caffeine content as decaffeinated coffee.
Caffeine is also a common ingredient in soft beverages, such as cola, which was initially made from kola nuts. A bottle of soft drinks generally contains 10 mg to 50 mg of caffeine. Energy drinks, such as Red Bull, contain 50 mg of caffeine per bottle. The caffeine in these beverages is derived from the original ingredients used in them or additives derived from decaffeinated coffee, and some are chemically synthesized. Guarana, the basic ingredient of many energy drinks, contains a lot of caffeine and a small amount of theobromine. The naturally occurring sustained-release excipients contain small amounts of theophylline.
One thing to note is that excessive caffeine intake can damage your body. It is a good choice to use a free and quick caffeine calculator to calculate your daily caffeine intake.