Caffeine decaffeinated coffee

Decaffeinated coffee products represented 18% of the coffee consumed in 1991 in the United States (31). Decaffeinated coffee was first developed commercially in Europe about 1900. The process as described in a 1908 patent (35) consists of first, moisturizing green coffee to at least 20% to facilitate transport of caffeine through the cell wall, and then contacting the moistened beans with solvents. 

To make an instant decaffeinated coffee product, the decaffeinated roast and ground coffee is extracted in a manner similar to nondecaffeinated coffee. Alternatively, the caffeine from the extract of untreated roasted coffee is removed by using the solvents described previously. 

In some cases, the solids themselves are subjected to extraction by a solvent. For example, in one process used to decaffeinate coffee, the coffee beans are mixed with activated charcoal and a high-pressure stream of supercritical carbon dioxide (carbon dioxide at high pressure and above its critical temperature) is passed over them at approximately 90°C. A supercritical solvent is a highly mobile fluid with a very low viscosity. The carbon dioxide removes the soluble caffeine preferentially without extracting the flavoring agents and evaporates without leaving a harmful residue. 

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... 

Methods for the decaffeination of green coffee beans, mainly with solvents after a steaming, have already been described. Even with the selective adsorption techniques to remove only caffeine, it is unlikely that the full character of the starting beans can be realized in a final decaffeinated beverage the result is that Robusta coffees are generally used to prepare decaffeinated coffee. The cost is kept down and the treatment, anyway, reduces any harsh or bitter flavor that the Robusta coffee may have had. The resulting beverage will be relatively caffeine-free, but Robusta coffee will contribute more soluble carbohydrates, phenols, and volatile fatty acids, and much less of the diterpenes found in Arabica coffees. 

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). 

Superko, H., Bortz, W., Williams, P., Albers, J. and Wood, P., Caffeinated and decaffeinated coffee effects on plasma lipoprotein cholestrol, apolipoprotiens and lipase activity A controlled, randomized trial. American Journal of Clinical Nutrition 54, 599-605, 1991. 

Hofer, I., Battig, K., Psychophysiological effects of switching to caffeine tablets or decaffeinated coffee under field conditions. Special Issue Caffeine research. Pharmacopsychoecologia 7(2), 169-177, 1994. 

The failure to find an effect in the American trial above was confirmed in a study conducted in the Netherlands, which also used paper-filtered, drip-brewed coffee.14 In that 12-week experiment, 23 women and 22 men who habitually drank 4 to 6 cups of coffee per day were assigned to consume 5 cups/day of either caffeinated (417.5 mg caffeine/day) or decaffeinated coffee (15.5 mg caffeine/day) for six weeks, and then switch for another six weeks. The blend of coffee beans was 71% Arabica and 29% Robusta for the caffeinated coffee, and 58% Arabica and 42% Robusta for the decaffeinated coffee. Lipid values at the end of both six-week study periods were almost identical. Total cholesterol was 5.47 vs. 5.48 mmol/ L (212 vs. 212 mg/dL), LDL-C was 3.41 vs. 3.40 mmol/L (132 vs. 131 mg/ dL), HDL-C was 1.52 vs. 1.52 mmol/L (59 vs. 59 mg/dL), and TG were 1.17 vs. 1.20 mmol/L (104 vs. 106 mg/dL) for the caffeinated vs decaffeinated coffee periods, respectively. Further, a small study of 12 Finnish men also failed to find an effect of caffeinated coffee on serum cholesterol levels.15 However, the study period was only three weeks which may have been insufficient. 

Massey and Opryszek9 elaborated further by showing that habitual caffeine consumption induced chronic hypercalcuria in young women (mean 24 years) after an oral caffeine challenge where they were fed either 300 mg of caffeine tablets per day or 6 mg caffeine per kilogram lean body mass (LBM) per day (range 274 to 325 mg/caffeine) mixed with decaffeinated coffee or tea when compared to a week of abstinence. Ad-... 

Oral caffeine loads added to decaffeinated coffee or tea Self report of daily intake of cups of coffee... 

Raaska, K., Raitasuo, V., Laitila, J. Neuvonen, P. J. (2004). Effect of caffeine-containing versus decaffeinated coffee on serum clozapine concentrations in hospitalised patients. Pharmacol. Toxicol, 94, 13-18. 

We continue our theme of coffee . Most coffees contain a large amount of the heterocyclic stimulant caffeine (I). Some people prefer to decrease the amounts of caffeine they ingest for health reasons, or they simply do not like to consume it at all, and they ask for decaffeinated coffee instead. 

Figure 5.8 Coffee is decaffeinated by constantly irrigating the ground beans with supercritical carbon dioxide schematic representation of a Soxhlet apparatus for removing caffeine from coffee...

Secondly, solid CO2 is relatively cheap. Finally, after caffeine removal, any occluded CO2 will vaporize from the coffee without the need to heat it or employ expensive vacuum technology. Again, we retain the volatile essential oils of the coffee. Even if some CO2 were to persist within the coffee granules, it is chemically inert, has no taste and would be released rapidly as soon as boiling water was added to the solid, decaffeinated coffee. 

The article Caffeine in coffee its removal why and how by K. Ramalakshmi and B. Raghavan in Critical Reviews in Food Science and Nutrition, 1999, 39, 441 provides an in-depth survey of the physicochemical factors underlying decaffeination of coffee with supercritical CO2. 

Unfortunately, the questionnaire did not distinguish between caffeinated versus decaffeinated coffee or instant versus brewed coffee. Positive associations with coffee use are seen for fatal large bowel cancer in both sexes, fatal coronary disease in males only, and possibly for all causes of death in males only. Both sexes were combined for large bowel cancer because the degree of association was essentially equivalent when examined separately for... 

As solvents, ionic liquids can be uniquely tuned to a particular purpose by adjusting the anion/cation ratio. To decaffeinate coffee, for example, you could create an ionic liquid that would just dissolve caffeine and nothing else. Current research suggests that ionic liquids can be recovered from solution and reused. 

You won t find this happening in your fireplace, though. It doesn t have enough heat or high enough pressure. The cores of stars have supercritical fluids, and the planet Jupiter has some gaseous layers that are supercritical and denser than water. Most decaffeinated coffee has its caffeine removed using supercritical carbon dioxide. 

It has been estimated that beverage consumption may provide the following amounts of caffeine per cup or average measure coffee, 30-150 mg (average 60-80 mg) instant coffee, 20-100 mg (average 40-60 mg) decaffeinated coffee, 2-4 mg tea, 10-100 mg (average 40 mg) cocoa, 2-50 mg (average 5 mg) cola drink, 25-60 mg. The maximal daily intake should not exceed about 1 g to avoid unpleasant side effects, e.g. headaches, restlessness. An acute lethal dose is about 5-10 g. 

Birth-weight effect. Caffeinated coffee alone had an adjusted odds ratio of 1.3 (95% confidence limits [CL] = 1.0, 1.7) for preterm delivery mothers who consumed both caffeinated and decaffeinated coffee had an adjusted odds of 2.3 (95% CL = 1.3, 4), whereas those who consumed only decaffeinated coffee showed no increased odds of small-for-gestational age birth, low-birth-weight or preterm delivery. A reduction in mean birth-weight of -3 g per cup per week (95% CL = -5.9, -0.6) for caffeinated coffee and an increase of +0.4 g per cup per week (95% CL = 3.7, 4.5) for decaffeinated coffee was found " h... 

Chromosome aberration induced. Lyo-philized extract of the roasted seed, in cell culture at a concentration of 3.9 mg/mL, was active on human lymphocytes. Caffeinated and decaffeinated coffees without S9 mix was tested. The extract produced weak activity with S9 mix . Extract of the roasted seed, in cell culture at variable concentrations, was active on human lymphocytes. Metabolic activation reduced the effect . 

The methylxanthines stimulate secretion of both gastric acid and digestive enzymes. However, even decaffeinated coffee has a potent stimulant effect on secretion, which means that the primary secretagogue in coffee is not caffeine. 

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 derived by extraction of coffee beans, tea leaves, and kola nuts. It is also prepared synthetically. Much of the caffeine of commerce is a by-product of decaffeinized coffee manufacture. The compound is purified by a series of recrystallizations. Caffeine finds use in medicine and in soft drinks. Caffeine is also available as the hydrobromide and as sodium benzoate, winch is a mixture of caffeine and sodium benzoate, containing 47-50% anhydrous caffeine and 50-53% sodium benzoate. This mixture is more soluble in water than pure caffeine. A number of nonprescription (pain relief) drugs contain caffeine as one of several ingiedients. Caffeine is a known cardiac stimulant and in some persons who consume significant amounts, caffeine can produce ventricular premature beats. 

Caffeine is a naturally occurring substance found in the leaves, seeds, or fruits of more than 60 plants. These include coffee and cocoa beans, kola nuts, tea leaves, guarana (Paulinia cupana) and Paraguay tea. Thus it is present naturally in many beverages, such as coffee, tea, and cola drinks, or is added in small amounts (up to 200 ppm) in some soft drinks and in foods such as chocolate. Caffeine is obtained by solvent or supercritical fluid extraction from green coffee beans, mainly during the preparation of decaffeinated coffee. 

---