Chemistry Project Essay

Caffeine is a naturally-occurring stimulant, shew in several plants. Caffeine is water soluble, and is extracted into the brewed loving cup when preparing afternoon afternoon tea leaf leaf leaf leaf, deep br accept tree, or other caffeinated drinks. The virtually well- cognise plants concealing caffein be the tea plant, Camellia sinensis, coffee, yerba mat, and guayusa. Although tea is known to cod a number of health benefits, heavy caffein use is known to pee unpleasant effects and negative impacts on health, including fear and insomnia, and for this reason many a(prenominal) tea drinkers seek to accommodate their caffein intake. The amount of caffein in tea tends to be downhearted, but is high enough to be a matter of concern for throng imbibition considerable quantities of tea, as well as mountain sensitive to caffein for medical reasons.The Caffeine divulgeicleHow very a lot caffein is in tea?The caffein field of tea varies astray from one(a) tea to the next, and depends on how the tea is brewed, but tends to be at bottom the range of 15-70mg per 8 ounce cup. Caffeine poop overly be measured in basis of milligrams of caffein per grams of juice little tea. A teaspoon of dry tea leaves tends to weigh around 2.5 grams, the amount unremarkably utilize to key out a single cup, although this varies greatly by the type of tea. One turn over of the caffeine content of teas (after steeping) shew that the caffeine content of tea varied from about 3 mg/g to 30mg/g, which would result in a cup of tea hold backing between 7.5 mg and 75 mg of tea.In most cases, tea has overmuch less caffeine than coffee a typical cup of coffee contains 80-135 mg of caffeine. However, it is important to none that these figures be per cup, non per overhaul, and in the case of large serving sizes, and in addition with espresso and other heavily-caffeinated drinks, the caffeine per serving finish be considerably higher(prenomina l). In the U.S. the standard small serving size is 12 ounces. A recent paper of commercial coffee vendors in Australia found that most a quarter of espresso samples contained over 120 mg of caffeine per serving, about 1/8th contained 167 mg or to a greater extent per serving, and the highest contained 214 mg per serving. The authors of this look at cogitate that the most often-cited figures on caffeine content of coffee tend to underestimate the actual caffeine content.How much caffeine is guard to consume? To place these figures in perspective, the current consensus of the Ameri pot Congress of Obstetricians and Gynaecologists is that it is safe for big(predicate) women to consume up to 200 mg of caffeine daily. For the general public, the Mayo clinic recommends that 200-300 mg of caffeine daily is safe, but that 500-600 mg daily roll in the hay beat a number of health problems.If drinking a relatively stronger tea containing 60mg / cup, 8 cups a solar day would be a safe amount, or 3 for pregnant women. For a weaker tea, with 30mg / cup, twice this amount would close up be a safe amount of caffeine. entertain in mind that unalike people answer diametricly to caffeine, so an amount that is safe or unpleasant for one person may non be healthy for everyone.L-theanine in tea interacts with caffeine In addition to caffeine, tea also contains L-theanine theanine fuel interact with caffeine, allowing a smaller dose of caffeine to bewilder a stronger effect in ground of boosting concentration and visual acuity. This may explain why tea seems to provide a stronger boost in alertness for some people than one would expect from its caffeine content alone.Do dense, green, or uncontaminating teas contain much or less caffeine? some(prenominal) tea companies, and even some reputable entities much(prenominal) as the U.S. Department of Agriculture, have do delusory generalizations about the caffeine content of broad classes of tea. It is a widespr ead myth that black tea contains to a greater extent caffeine than green tea, and another myth that white tea contains the least caffeine of all teas.Studies that have actually examined the caffeine content of a large number of different teas have consistently found that caffeine levels vary more among individual teas than crossways broad categories of tea such as black, white, green, oolong, or pu-erh. A study published in 2005 in the Journal of Food Science listed, among other things, the caffeine content of 77 different teas, and found a broad range of caffeine content among both(prenominal) green and black teas. Surprisingly, the tea in this study that was found to contain the most caffeine was a white tea, solidly dispelling the myth about white teas caffeine content.A more recent study in the 2008 Journal of analytical Toxicology examined the caffeine contents of a number of teas, and found that they ranged from 14 to 61 mg per 6 or 8 oz serving, with no observable trend in caffeine concentration due to the variety of tea. Very few tea companies have examined the caffeine content of a large number of samples of their teas one that has, Camellia Sinensis Tea House, found similar results, that the caffeine level varies widely from one tea to the next, and does not show clear trends of caffeine levels across different varieties of teas.One possible exception to this observation is that matcha is known to contain very high levels of caffeine, consistently much higher than other teas. This is due in part to higher caffeine levels in the leaf apply to produced matcha, but it is also due to the fact that, because matcha is a powdered tea, the entire tea leaf is consumed when create from raw material, so a cup of prep ard matcha contains 100% of the caffeine in the leaf.What determines the amount of caffeine in a particular tea?Caffeine protects the tender juvenility leaf buds of the tea plant from being eaten by insects.There are so many different factors influencing the caffeine content of tea, that it is very hard to make generalizations predicting the caffeine content of tea. Caffeine levels vary widely from one particular tea to the next. The only definite way to know the caffeine level of a particular tea is to actually test it in a laboratory.Tea place be made from different parts of the tea plant, and these parts contain different quantities of caffeine. Leaf buds (tips) and younger leaves are higher in caffeine than older, mature leaves. This pattern can be explained by the fact that, for the tea plant, caffeine acts a natural insecticide, serving to protect the plant against being eaten by insects. Since the tips and tender young leaves are most vulnerable to insects, these parts of the plant are highest in caffeine the older leaves are tougher and frankincense pooh-pooh in caffeine. Tippy teas such as Yunnan Gold or Silver Needle sportsmanlike Tea (Bai Hao Yinzhen) are thence higher in caffeine than large-leaf teas suc h as Lapsang Souchong, a black tea (Souchongs are made of mature leaves) or Shou Mei, a white tea.The varietal (cultivar or specific horticultural variety) of tea plant used to produced tea can profoundly affect caffeine levels in tea. Varietal is commutative of type of tea (green, white, black, oolong, etc.), and different types of tea can be produced from the same varietal. Variation in caffeine content among different varietals can lead to teas heavy(p) under similar conditions, with similar appearance and other qualities, having different caffeine levels.Roasting can also reduce the caffeine levels in tea. In the 2005 study mentioned above, one particular sample of Hojicha, a Japanese roasted green tea, was found to have less caffeine even than some decaffeinated teas. Oolong teas are usually roasted to varying degrees, and can be lower in caffeine, although like all types of tea, oolong teas vary greatly in caffeine content. It should be noted that the cook borderes both fo r hojicha and oolongs vary greatly, and the caffeine content of most of these teas has not been extensively studied, so it is not safe to conclude that hojicha or roasted oolong is necessarily low in caffeine.The deceaseing of tea with caffeine-free ingredients to produce flavored teas can result in a lower fit caffeine content so long as less total tea leaf is used in the blend. Scenting tea with flowers or flavoring tea with essential oils of plants does not add as much weight as blending with loose herbs, and thus does not lower the caffeine content (by weight) of the blend as much. How you brew tea affects caffeine contentThe quantity of leaf used and the length of clipping the leaves are steeped both directly influence the caffeine content of the final cup of tea. Using more leaves and steeping for a longer time both adjoin the caffeine in the resulting cup. Our page on brewing tea has more discussion of how to brew tea. atomic number 50 you decaffeinate your own tea by st eeping it legal briefly in water? Short answer no. A number of sources make the claim that you can decaffeinate your own tea by making a brief infusion in hot water, and then discarding this infusion. Unfortunately, this process does not work if it did, tea companies would not have to resort to expensive and involved decaffeination processes to produce decaf tea. Caffeine tends to diffuse in hot water at the same rate as many of the chemicals responsible for the flavor and aroma of tea, so if the tea still tastes flavorful, it probably still contains caffeine.Most (but not all) herbal tea teas contain no caffeine Although caffeine does occur in a number of plants, the overtake majority of herbal teas are caffeine free. The most notable exception is Yerba mate. Other plants containing caffeine are very rare as ingredients in herbal tea.In addition to exploring other herbal teas, people desiring caffeine-free tea-like drinks might want to try South African rooibos and honeybush, two plants which are often set forth as being similar to tea in flavor, health benefits, and manner of production.