Caffeine is also a common ingredient of soft drinks
such as cola and energy drinks where it is deliberately
added as a flavoring agent and to make the drinks
addictive. Caffeine content in soft drinks varies by
brand from 10 to 50 mg of caffeine per serving (Violeta
et al., 2010); however the US Food and Drug
Administration (FDA, 2006) limits the maximum
amount in carbonated beverages to 6 mg/oz. Therefore
caffeine content allowed in soft drinks may be in the
range between 30 and 72 mg/355 mL (12 oz) or 8.45-
20.28 mg/100 mL (NSDA,1999)