Coffee caffeine content

Caffeine was extracted from ficw varieties of roasted coffee beans and was determined in parallel by (1) measurement of spot area after thin layer chromatography on silica gel GF plates (development with chloroform/ cyclohexane/glacial acetic acid, 8 2 1, visualization in UV light), and (2) Kjeldahl N determination. Caffeine contents by (1) and (2), respectively, in the five varieties analyzed were (percent in DM) Santos lave 0, 1.10, and 1.12 Java Robusta 3, 1.19, and 1.22 Camerun Robusta 2, 1.16, and 1.19 Mocca 2, 1.21, and 1.26 Guatemala 0, 1.18, and 1.20. (1) is considered slightly less accurate than (2) but rather easier and more rapid.21... 

A method for determining the caffeine content of regular and decaffinated green and roasted coffee beans and of regular and decaffeinated coffee extract powders, using HPLC, is specified in a British Standard Instruction.34 Caffeine is extracted from the sample with water at 90°C in the presence of magnesium oxide. The mixture is filtered and an aliquot purified on a silica microcolumn modified with phenyl groups. The caffeine content is then determined by HPLC with UV detection.35... 

Coffee. Determination of the caffeine content, HPLC method, Association Francaise de Normalisation French Standard, France, NF ISO 10095, 1992. 

Methods of test for coffee and coffee products. Part 12. Coffee determination of caffeine content (routine method by HPLC), British Standards Institution, United Kingdom, British-Standard, BS 5752 Part 12, 1992. 

One of the most significant differences between Arabica and Robusta coffees is in the caffeine content. Robusta coffees contain almost twice the caffeine found in Arabica coffees. There are some other differences recognized thus far Robustas contain almost no sucrose and only very small amounts of the kaurane and furokaurane-type diterpenes they contain higher proportions of phenols, complex carbohydrates (both soluble and hydrolyzable), volatile fatty acids on roasting, and sulfur compounds, all in comparison with Arabicas. References to these distinctions can be found in Chapter 6 of this book. 

The caffeine content of coffee is given in Table 16.15-152> 153 Recently determined values for the caffeine content of Brazilian coffees, 0.2 to 109 mg/150 ml (cup),154 were somewhat lower than those reported in Table 16. 

Belyaya, K. J., Clifford, M. N., Individual chlorogenic acids and caffeine contents in commercial grades of wet and dry processed Indian green robusta coffee, J. Food Sc 1. Technol, 32(2),104, 1995. (CA123 197159w)... 

Charrier, A., Variation of the caffeine content in coffee plants, Colloq. Int. Chim. Cafes., 7, 295, 1975. (CA85 156639f)... 

Caffeine consumption is primarily due to coffee, tea and soft drinks. In the U.S., it is estimated that coffee contributes to 75% of the total caffeine intake, tea is 15%, and soda with caffeine accounts for 10% 5 chocolate and other caffeine-containing foods and medications contribute relatively little to overall caffeine exposure. Caffeine also varies by sources tea leaves contain 1.5 to 3.5% caffeine kola nuts contain 2% caffeine and roasted coffee beans contain 0.75 to 1.5% caffeine.6 Coffee varies in caffeine content some analyses have estimated that caffeine may range from 0.8 to 1.8%, depending on the type of coffee.7 Crops of coffee, tea, and cocoa are very similar in their production periods and their useful life in production. Typically coffee, tea, and cocoa trees can be productive with crops every 5 years for a total period of 40 years,8 or an estimated 8 yields per tree. 

By weight, tea leaves have double the caffeine as coffee beans 25 however, the caffeine content is greatly diluted during preparation. Caffeine in tea has been reported to range from 2.7 to 4.1% in selected varieties of tea,7 comparable with an estimate of 4% caffeine content in tea.26 While tea is the most commonly consumed caffeinated beverage, the caffeine content is only one third to one half that of coffee, contributing less to overall caffeine exposure than coffee. 

As shown in Table 9, the caffeine content of coffee, tea, and other products can vary dramatically.5 29 33 Caffeine content in a cup of coffee has been reported as 74 mg for percolated coffee and 112 mg for automatic drip coffee, showing substantial differences according to preparation.34 Instant coffee is significantly less at 66 mg and caffeine from decaffeinated coffee is negligible (1 to 3 mg caffeine). 

Individual sensitivity to coffee drinking may or may not be related to its caffeine content. Other compounds found in coffee are probably responsible, as the same individuals can often drink tea without adverse gastrointestinal effect. 

In addition to coffee and tea, the psychological effects of caffeine can be obtained from a number of other food sources. Chocolate is a popular and widely consumed source, but the drug is also found in considerable quantities in a number of medications, both prescription and over-the-counter (OTC). Caffeine tablets (e.g., No-Doz) are sold for those who use the drug to study, drive, or engage in other activities. Less obvious is the caffeine content in analgesics, cold preparations, and anorectants. 

The world s coffee supply comes primarily from two major types of coffee beans, Arabica (Coffea arabica) and Robusta (Coffea canephora), which differ in several characteristics as well as caffeine content. Arabica is favored for its finer aroma, flavor, and body, and contains 1% caffeine. Robusta is neutral and contains twice as much caffeine.1 The ratio of... 

The results of these studies, when considered together and with the observational studies reviewed above, suggest that any significant effect of coffee on serum cholesterol levels is likely due to something other than caffeine content. 

Author/ year nationality Coffee type/ preparation type/ coffee chemical Caffeine content (mg/day) Coffee bean/ brand used Cups or amount/ day... 

See Chapter 3 for caffeine content of tea, Chapter 7 for caffeine content of chocolate foods/ beverages, and Chapter 13 for caffeine content of coffee. 

Example The B E = const, linked scan [93] has been employed to quantify the caffeine content of coffee, black tea, and caffeinated cola softdrinks. [99] Caffeine, M" = 194, was determined by spiking the sample with a known concentration of [D3]caffeine, = 197, as internal standard. Both molecular ions dissociate to form a fragment ion at m/z 109 which was selected as m2. Then, the precursor ion scan showed either molecular ion, mi and [D3]mi, as precursor of the ion at m/z 109. The ratio of peak intensities was taken as a measure for the relative concentration of analyte and labeled standard (Fig. 4.29). 

Carcinogenic activity. Decoction of the seed, administered orally to adults, was inactive. There was no association between colorectal adenomas and consumption of extract . Roasted seed, administered to male rats at a dose of 6% of diet for 2 years, was inactive. Water extract of the roasted seed, administered to female rats at a dose of 6% of diet, was inactive. Regular and decaffeinated instant coffees were studied. Coffees with highest caffeine content showed lower tumor incidence k Hot water extract of the roasted seed, administered orally to 18 rats at a dose of 2% for 120 days... 

Too much caffeine is harmful for many people, and even small amounts cannot be tolerated by some unlucky individuals. How much caffeine is in a chocolate bar How does that amount compare with the quantity in coffee or soft drinks At Bates College in Maine, Professor Tom Wenzel teaches his students chemical problem solving through questions such as these.4 But, how do you measure the caffeine content of a chocolate bar ... 

CNS, smooth muscle T diuresis X- pit aggregation Available forms Daily t doses w/ max 3 g PO daily Contra Avoid in PRG lactation, CAD, hyperthyroidism, anxiety disorders d/t high, caffeine content Notes/SE Insomnia, tach, anxiety, N/V, HA, HTN, Sz Interactions T Effects OF anticoagulants, anti-pits, BBs, bron-choclilators T risk of hypertensive crisis W/ MAOIs T effects W/ cimetidine, ciprofloxacin, ephedrine, hormonal contraceptives, dieophylline, cola, coffee X-effects OF adenosine, antihypertensives, benzodiazepines, Fe, X- effects W/ smoking EMS Tinctures contain EtOH may exacerbate GI disorders HTN T effects of anticoagulants and BBs... 

The coffee bean contents of the extractors are discharged and refilled within certain time-periods (6). The decaffeination process is providing the decaffeinated coffee beans as well as the caffeine as valuable products. 

Caffeine is present in coffee, tea, and chocolate. These plant-derived beverages and foods also contain the other methylxanthines, which some scientists say serve as defense chemicals for leaves and berries produced in climates where there is no winter to kill off chewing bugs. Tea contains mostly caffeine, with small amounts of theophylline and theobromine, but tea is a weaker plant extract than the stronger brew, coffee. Theobromine is the primary methylxanthine found in cocoa, which also contains a small amount of caffeine per cup. Caffeine content ranges from as little as 5 mg in a cup of hot cocoa to 300 mg in 6 oz (177 ml) of espresso. Colas have about 50 mg per 12 fl oz (355 ml). 

The FDA allows soft drink manufacturers to add caffeine to a limit of 72 mg per 12-ounce (355 ml) serving. Coffee and tea, containing caffeine naturally rather than as an additive, are not regulated for caffeine content. 

Coffee is not the only source of large doses of caffeine. Chocolate bars, for example, contain approximately 30 mg of caffeine. In addition, over the past 10-15 years soft-drink manufacturers have produced a number of caffeinated beverages including orange juice and water. However, colas remain the principal vehicle to Feed the Rush. A comparison of caffeine content of various colas is shown in Table 11.6. 

Qll Both alcohol and the caffeine content of coffee act directly on the gastric mucosa to stimulate acid and pepsinogen secretion, so reduction in their use should help the patient. Smoking can also worsen dyspepsia (indigestion) and heartburn, possibly via actions of nicotine on the stomach wall. 

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