The genus Cinnamomum

Chemistry of Cinnamon and Cassia 81
natural camphor. From time immemorial the camphor tree has been growing in
China, Japan and Taiwan (Guenther, 1950). Through Marco Polos thirteenth-century
journal camphor became widely known as a curious and valuable product of the orient.
From that time, camphor has occupied an important position in commerce. Due
to increase in demand, production of camphor, which originated in China, later spread
to Japan and Taiwan. True cinnamon as well as cassia are considered as spices on
account of their distinct chemistry. However, C. camphora has camphor as the main
chemical constituent. The root bark oil of C. verum also has camphor as a main
constituent. This makes the biosynthesis of volatiles of Cinnamomum quite interesting
(Senanayake, 1977).
Analytical Methodology
Classical methods
The methods in vogue several decades ago, despite their limitations, determined
the standard sample of a cinnamon product. These methods could be termed classical
methods for the assessment of quality. The development of these methods, and the
formulation of standards for cinnamon and cinnamon oils, took place in the era
preceding the development of modern analytical methods based on instrumentation.
Both classical and modern studies of Cinnamomum volatiles have been reviewed
by Senanayake (1977), Wijesekera (1978), Jayewardene (1987), Senanayake and
Wijesekera (1989).
The advent of instrumental techniques
Gas liquid chromatography
The introduction of analytical methods based on gas liquid chromatography (GLC)
created a new dimension in the study of volatiles. Relatively minor compounds, which
could not be detected by classical methods, could be detected by GLC. As a result,
the number of compounds detected in cinnamon oils, as in the case of all essential
oils, increased several-fold. Even though the quantity of purified fractions that could be
obtained by GLC was quite small, a combination of infrared (IR) spectroscopy and mass
spectroscopy (MS) helped in the positive identification of the compounds separated.
The improved techniques helped to develop the concept that aroma characteristics
could often be considerably modified by the presence or absence of the compounds
present in small quantities, and need not necessarily be dependent solely on the major
compounds present.
Datta et al. (1962) identified benzaldehyde and cinnamic aldehyde in cassias (Saigon,
Korintji and Batavia) oils by GLC. They proposed that GLC could be used to identify
the geographical origin of spices. Bhramaramba and Sidhu (1963) identified -pinene,
-phellandrene, p-cymene, caryophyllene, humulene, linalool, and O-methyl eugenol
in the non-eugenol fraction of Indian cinnamon leaf oil by GLC. Lawrence (1967)
initially proposed that the GLC profile of cinnamon oils could serve as an analytical
control of purchased cinnamon oils, and Wijesekera and Jayewardene (1972) showed
the characteristic differences between the oils of cinnamon and cassia, where GLC
profiles were compared.