Abstract:
Ceylon cinnamon is valuable spice rich in volatile oils and bioactive compounds.
However, harvesting is restricted to specific times of the year due to peeling
difficulties in the bark during certain physiological stages and dry weather,
creating a significant challenge in meeting the constant, year-round demand. This
study investigated the interplay between chemical composition and peelability of
the bark across three Cinnamomum zeylanicum varieties: Sri Gemunu, Sri
Wijaya, and Common. Ten samples were collected from each variety, depending
on the peelability of the bark. The bark oil was extracted using the Clevenger
apparatus, which adapted the hydrodistillation method, to analyse its chemical
composition using a Gas Chromatography (GC) instrument. Further,
polyphenols, flavonoids, and tannins in powdered bark samples were determined
using UV-VIS spectroscopy. The data obtained were analyzed using two-way
ANOVA, considering variety and peelability. Gemunu and Wijaya varieties had
shorter peeling times, while non-peelable samples took longer times than their
peelable counterparts. Gemunu had the highest oil yield, and peelable samples
showed slightly higher oil volume, indicating a marginal significance between
peelability and oil yield (P=0.0666). Using GC reference data, α-pinene,
Eucalyptus, β-caryophyllene, Linalool, Trans-cinnamaldehyde, Cinnamyl acetate,
and Eugenol were identified among the constituents present in the bark oil.
Trans-cinnamaldehyde represented the greatest concentration in all peelable and
non-peelable bark samples (55% to 65%), with cinnamyl acetate as the next most
prominent compound. The others were found in less than 10%. However, in
Wijaya, cinnamyl acetate was found to be higher in non-peelable samples
(23.48%) than the peelable ones (17.49%), and again, the opposite trend was
observed for the common variety. There was no significant difference observed
between the peelable and non-peelable samples, which indicates that both of
these types can be used equally in their applications, even in less favorable
conditions. Non-peelable bark of Wijaya variety had the highest flavonoid
content, which was 2571 mg Quecertin Equivalents/g powder, and polyphenol
content, which was 250 mg Gallic Acid Equivalants/g powder. Tannin was
higher in non-peelable bark of the Gemunu variety (868 mg Tannic Acid
Equivalents/g powder). Therefore, the less-peelable bark could also be a good
source of bioactive compounds.
