Low caffeine

Potential consumer benefits from biotechnology (56) are cost and quaUty. The use of biotech means to increase the level of various sulfur-containing amino acids in coffee proteins, and to enhance sucrose and oil levels, could have an impact on the flavor and aroma of the finished ground coffee product. Also, caffeine level modification/elimination through genetic manipulations of the coffee plant could yield low caffeine coffee without additional processing by the manufacturer. 

Asamoa and Wurziger tabulated the caffeine content of a variety of cocoa beans.22 The mean concentration (percentage in fat-free samples) in Amelonado and Amazonas beans, respectively, after 5 d of fermentation at various stages of maturity were green beans 0.06,0.19 yellow 0.09,0.18 orange 0.08, 0.23 and black 0.10, 0.22. These results confirmed significant differences between the two varieties and also the low caffeine content of Forastero-type beans. The caffeine content of 16 other samples of various... 

Japanese scientists develop a genetically engineered coffee plant the produces low caffeine beans... 

Ashihara, H. and Grozier, A. (1999) Biosynthesis and catabolism of caffeine in low-caffeine containing species of Coffea.. Agric. Food Chem., 47, 3425-31. 

In healthy boys, there were increases in subjective anxiety in long-term low-caffeine users, and withdrawal symptoms in high-caffeine users. No beneficial effects of caffeine use were found (37). It has been recommended that children should take caffeine only in analgesic products and in a dose related to their age (SEDA-5, 6). 

As catechins are good UV chromophores with absorption maxima at 210 and 270-280 nm, UV and diode array detectors (DAD) are traditionally the most popular detectors employed for their determination in tea infusions. A typical HPLC chromatogram for green tea extract with low caffeine content is shown in figure 6.1. 

Many people think that a short extraction time will ensure the low caffeine content of tea, but this household tip did not stand experimental scratiny. In a series of tests, tea prepared by 1-minute extraction contained 20-30 mg of caffeine, 3 min brought 34-35 mg, whereas 5 min resulted in 30-50 mg. So shortening the time of extraction does not decrease caffeine levels significantly, but it does decrease the general quahty of the drink. 

Cameroon produces a caffeine-free Coffea species, Coffea chanieriana, but in the West solvents such as dichloromethane, ethyl acetate or even supercritical CO2 are used to dissolve the caffeine from the coffee beans to make decaffeinated coffee. Scientists can notv engineer low-caffeine coffee plants, too. 

Decaffeination Regulations. Eor decaffeinated roasted coffee, EEC standards indicate the maximum content of caffeine as 0.1% db for decaffeinated instant coffee it is 0.3% db. In the United States, decaffeination usually signifies that 97% of the caffeine has been removed. Permissible solvents for decaffeination processes are defined by national legislation, eg, EDA or EEC directive. The maximum residual solvent content after decaffeination, roasting, or instant coffee processing is to be kept within good manufacturing practice, ie, very low ppm levels or below at point of sale (46). 

The effect of concentration of cationic (cetylpyridinium chloride, CPC), anionic (sodium dodecylsulfate, SDS) and nonionic (Twin-80) surfactants as well as effect of pH value on the characteristics of TLC separ ation has been investigated. The best separ ation of three components has been achieved with 210 M CPC and LIO M Twin-80 solutions, at pH 7 (phosphate buffer). Individual solution of SDS didn t provide effective separation of caffeine, theophylline, theobromine, the rate of separ ation was low. The separ ation factor and rate of separ ation was increase by adding of modifiers - alcohol 1- propanol (6 % vol.) or 1-butanol (0.1 % vol.) in SDS solution. The optimal concentration of SDS is 210 M. 

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. 

In addition the role played by the sorbent on which the chromatography is carried out must not be neglected. For instance, it is only on aluminium oxide layers and not on silica gel that it is possible to detect caffeine and codeine by exposure to chlorine gas and treatment with potassium iodide — ben2idine [37]. The detection limits can also depend on the sorbent used. The detection limit is also a function of the h/ f value. The concentration of substance per chromatogram zone is greater when the migration distance is short than it is for components with high h/ f values. Hence, compounds with low h/ f values are more sensitively detected. 

The basic process outline is depicted in Figure 5.2 moist un-roasted coffee beans and CO2 are fed counter-currently into the extractor under supercritical conditions. Caffeine is selectively extracted into the CO2 and this stream is led to a water-wash column to remove caffeine at a reduced pressure, the CO2 being recycled back to the extraction column. Extraction of the caffeine into water is necessary to avoid dropping the CO2 pressure too low, since compression is energy-intensive. There is now the problem of separating the caffeine (which is used in soft drinks and pharmaceu-... 

Hypotension may be related to alterations in levocarnitine levels during dialysis. Patients who have low levels of levocarnitine may benefit from supplementation. Levocarnitine is administered as doses of 20 mg/kg intravenously at the end of each dialysis session. However, levocarnitine should not be used as a first-line agent for the treatment of hypotension because of the significant cost associated with the treatment. Patients receiving levocarnitine should be evaluated every 3 months for response to therapy.47 Other preventive measures that have not been well studied include caffeine, sertraline, or fludrocortisone. 

A 35-year-old woman with a history of hypertension presents to your clinic complaining of low energy and irritability. She reports not following any specific diet because they have all failed in the past. She does admit to eating out frequently. This patient does not exercise because her job and her kids are too demanding. Patient does smoke a half pack of cigarettes per day and consumes low-calorie, caffeinated and alcoholic drinks most days. Her BMI is 32 kg/m2, and her waist circumference is 38 in (97 cm). 

The desirability of partial shade on tea estates has been a controversial subject. Desirable effects include temperature moderation at the leaf surface, which decreases low-humidity stress, and an increased yield of chlorophyll, amino acid, and caffeine production. The undesirable effects include decreased photosynthetic activity and competition for water and solid nutrients by the shade tree employed. In general, the trend has been toward the elimination of shade in most black-tea growing areas. Green tea products benefit from the additional chlorophyll and amino acid pro-... 

Green tea quality is dependent to a large extent on amino acid levels, especially that of theanine.97 Ascorbic acid content, although very low, also correlates positively with quality. Free reducing sugars and catechin gallates show a negative correlation.98 Caffeine levels do not have much effect on quality. 

Although low levels of methylxanthines have been detected in the leaves and flowers of T. cacao, the primary storage location is within the seed or bean.16 The cocoa bean is the major natural source of the methylxanthine theobromine, but contains only small amounts of caffeine. Theophylline has been detected in cacao beans, but at such low concentrations that its presence generally is ignored. Together, theobromine and caffeine account for up to 99% of the alkaloid content of T. cacao beans. Alkaloid content is affected by genetic makeup, maturity of beans at harvest, and fermentation process. Analytical methodology also is partially responsible for some of the disparity in methylxanthine values since many early methods were unable to separate theobromine and caffeine. 

According to Schutz, it is well known that cocoa contains about 2.5% by weight of theobromine and caffeine.29 Although the presence of theophylline has been demonstrated, its concentration is so low that it is generally ignored. In a summary of the literature values for 27 commercial cocoa powders and cocoa masses, Hadorn found that the mean total alkaloid content was 3.36 0.48%.23 Theobromine and caffeine content of several cocoa powders is shown in Table 6. HPLC analyses by DeVries et... 

Consumption of sweet chocolate in the U.S. is low. The majority of chocolate consumed is milk chocolate produced from chocolate liquor, sugar, cocoa butter, and milk solids. Because most milk chocolate produced in the U.S. contains 10 to 12% chocolate liquor, differences in methylxanthine content among commercial milk chocolate are due more to the varieties and blends of cocoa bean (Table 9). Based on analytical data from seven brands of commercial milk chocolate, a typical 40-g milk chocolate bar contains approximately 65 mg theobromine and less than 10 mg caffeine.28 Milk chocolate bars containing other ingredients, such as peanuts, almonds, and confectionery fillings, obviously contain less methylxanthines. In a survey of 49 marketed chocolate and confectionery products, theobromine concentrations ranged from 0.001 to 2.598% and caffeine content from 0.001 to 0.247%.33... 

The percentage of binding to plasma protein is low for caffeine (35%) and theobromine (15 to 25%), but fairly high for theophylline (55 to 67%). This higher binding of theophylline should be considered when it is used as a prescription drug. 

Caffeine was found to significantly increase muscular force output at low frequencies of electrical stimulation (10 to 50 Hz), but at high frequencies (100 Hz) there was no significant increase in maximal voluntary contractions or endurance.38 Such results may suggest that at high intensity, the sympathetic response may negate the effects noted at low intensity.39... 

Berglund, B. and Hemmingsson, P., Effects of caffeine ingestion on exercise performance at low and high altitudes in cross-country skiers, International Journal of Sports Medicine, 3, 234, 1982. 

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