VARIATION IN CINNAMON BARK CHEMICAL COMPOSITION AMONG VARIETIES IN RELATION TO PEELABILITY

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.