2007 Elsevier Ltd. All rights reserved.
Keywords: Absorbance; Caffeine; Characterization; Extraction; UV/vis spectrophotometer
1. Introduction
Caffeine is found in various kinds of foods and drinks
that we consume in daily life (Singh & Sahu, 2006). It
causes various physiological effects such as relaxation of
bronchial muscle, stimulation of the central nervous system,
gastric acid secretion and dieresis Bolton and Null
(1981). And their concentration in vivo is a key mark for
various disorders including heart disease, carcinogenesis,
kidney malfunction and asthma (Zhang, Lian, Wang, &
Chen, 2005). On the other hand, chemical analysis of caffeine
in coffee beans is also used as an additional tool for
evaluating coffee quality. Higher caffeine contents associated
with highest quality samples compared to other Arabic
samples have been reported by Franca, Mendonca,
and Oliveira (2005). Therefore, establishing a rapid and
cheap analytical method for the determination of caffeine
in coffee beans has an interest for a wide range of physiological
effects on the human body and quality controls.
Several chemical