Caffeine is a naturally arising alkaloid which is found inthe leaves, seeds and fruits of over 63 plants species worldwide. It is analkaloid of methylxanthine family. The methylxanthines caffeine(1,3,7-trimethyxanthine), theobromine (3,7- dimethylxanthine), and theophylline(1,3-dimethylxanthine) can be usually found in tea leaves, cola nuts, coffeebeans, cocoa beans, mate leaves andother kinds of plants. While coffee and tea beverages naturally containcaffeine and other methylxanthines, Caffeine aids as an ingredient in manycarbonated soft drinks including colas, pepper-type beverages, and citrusbeverages. Pure caffeine occurs as odorless, white, fleecy masses, glisteningneedles of powder.
Its molecular weight is 194.19g, melting point is 236°C,point at which caffeine sublimes is 178°C at atmospheric pressure, pH is 6.9(1% solution), specific gravity is 1.
2, volatility is 0.5%, vapor pressure is760mmHg at 178°C, solubility in water is 2.17%, vapor density 6.7.
Caffeine hasdrawn more attention in the past decades due to its physiological effectsbeyond that of its stimulatory effect. The Food and Drug Administration (FDA)defines caffeine as a generally recognized as safe (GRAS) substance. However,FDA specifies that the maximum amount in carbonated beverages is limited to0.02% (FDA 2006).
Therefore, the highest legal amount of caffeine allowed in a355 mL (12oz) can of soft drink is about 71mg. Caffeine has attracted theinterest of consumers and health professionals alike due to its wideconsumption in the diet by a large percentage of the population and itspharmacological effects in humans (Mandel 2002). Its physiological effects onmany body systems have been informed by researchers, containing the centralnervous, cardiovascular, gastrointestinal, respiratory, and renal systems(Nehliget al 1992). The International Olympic Committee (IOC) defined caffeineas a drug and abuse is indicated when athletes have urine caffeineconcentrations higher than 12?g/mL.
