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This page provides supplementary chemical data on caffeine. ... Solubility in water. 2.17 g/100 mL (25 °C) 18.0 g/100 mL (80 °C) ... 192 mg/kg (rat, oral) [3]
Plasma caffeine levels are usually in the range of 2–10 mg/L in coffee drinkers, 12–36 mg/L in neonates receiving treatment for apnea, and 40–400 mg/L in victims of acute overdosage. Urinary caffeine concentration is frequently measured in competitive sports programs, for which a level in excess of 15 mg/L is usually considered to ...
In espresso, however, likely due to its higher amount of suspended solids, there are significant contents of magnesium, the B vitamins, niacin and riboflavin, and 212 mg of caffeine per 100 grams of grounds. [165] One psychoactive chemical in coffee is caffeine, an adenosine receptor antagonist that is known for its stimulant effects. [166]
[6] [7] [8] After plain water, tea is the most widely consumed drink in the world. [9] There are many different types of tea; some have a cooling, slightly bitter, and astringent flavour, [10] while others have profiles that include sweet, nutty, floral, or grassy notes. Tea has a stimulating effect in humans, primarily due to its caffeine ...
Free caffeic acid can be found in a variety of beverages, including brewed coffee at 63.1-96.0 mg per 100 ml [7] and red wine at 2 mg per 100 ml. [8] It is found at relatively high levels in herbs of the mint family, especially thyme, sage and spearmint (at about 20 mg per 100 g), and in spices, such as Ceylon cinnamon and star anise (at about 22 mg per 100 g).
The term "herbal" tea is often used to distinguish these beverages from "true" teas (e.g., black, green, white, yellow, oolong), which are prepared from the cured leaves of the tea plant, Camellia sinensis. Unlike true teas, most tisanes do not naturally contain caffeine (though tea can be decaffeinated, i.e., processed to remove caffeine). [4] [5]
In China, this is evident in many cooked pu-erh teas, as well as more heavily fired Wuyi Mountain oolongs; commonly referred to as 'zhonghuo' (mid-fired) or 'zuhuo' (high-fired). [citation needed] A generally accepted statistic is that a cup of normal black (or red) tea contains 40–50 mg of caffeine, roughly half the content of a cup of ...
There is no standard value for "a cup of coffee." The caffeine content of cola drinks and most energy drinks can be difficult to determine, because in many cases the labels do not indicate the dose per serving. Caffeine doses in these beverages range from 20 to 30 mg in some soft drinks, up to 350 mg or more in some energy drinks.