Characterization and Distribution of Coumarin, Cinnamaldehyde and Related Compounds in Cinnamomum spp. by UPLC-UV/MS Combined with PCA

Cinnamon, which has been known for its flavoring and medicinal properties from ancient time, remains one of the most popular flavoring agents used in the food and beverage industry. The name „cinnamon“ correctly refers to the bark of Cinnamomum zeylanicum Blume (Lauraceae), a small evergreen tree native to Sri Lannka [1]. However, other species of the same genus such as C. aromaticum, C. loureiroi and C. burmannii are commonly sold with the label of cinnamon. Even though cinnamaldehyde, the dominant flavoring agent, is the major constituent in all these Cinnamomum species the presence of a toxic compound, coumarin, in some of these species has raised safety concerns. There are no imposed limits of coumarin content in food and beverages in the US, but European countries have set a maximum limit of 2mg/kg for food beverages and 10mg/L for alcoholic beverages [2]. The purpose of this study is to find a possible discriminant method among Cinnamomum species, and to develop an analytical method to quantify the cinnamaldehyde and coumarin content in these species and cinnamon flavored food.

An ultra-performance liquid chromatography coupled with a PDA detector and a mass spectrometry (UPLC-UV/MS) method has been developed to characterize coumarin (1), cinnamyl alcohol (2), cinnamaldehyde (3), cinnamic acid (4), eugenol (5) and cinnamyl acetate (6) in three Cinnamomum species and 48 commerical samples of cinnamon powder or bark. The established relative composition of coumarin, cinnamaldehyde and its related compounds was used to carry out a chemotaxonomical study on Cinnamomum species by means of principal component analysis (PCA). The results demonstrated that the qualitative and quantitative differences in coumarin and cinnamaldehyde were useful for species identification in cinnamon powder or bark samples. The developed method was successfully applied for the analysis of cinnamon food products including cookies, biscuits, cereal and fruit sauce, and is useful in quality control of products claiming to contain cinnamon.

Fig.1: UPLC-UV Chromatograms of standards (A) and extracts of Cinnamomum spp. (B-D) at 280nm and PCA Analysis

Acknowledgements: This research is supported in part by „Science Based Authentication of Dietary Supplements“ and „Botanical Dietary Supplement Research“ funded by the Food and Drug Administration grant numbers 5U01FD002071–09 and 1U01FD003871–01, and the United States Department of Agriculture, Agricultural Research Service, Specific Cooperative Agreement No. 58–6408–2-0009. The authors sincerely thank Mr. Ananda Wickramasinghe for his immense support in the procurement of some of the authenticated samples used in this study. References: [1] Britannica Online Encyclopedia (http://www.britannica.com/EBchecked/topic/118117/cinnamon). [2] Sproll C, et al. (2008) Food Chem 109(2): 462–469.