Cinnamon

Botanical Profile

Ceylon cinnamon and cassia cinnamon types differ markedly in their coumarin, aroma and quality profiles; statements should therefore be interpreted in relation to the particular species and raw material.

Note on species delimitation: Depending on commercial and literature context, the term cinnamon may refer to several Cinnamomum species.

Cinnamon denotes aromatic bark raw materials from various Cinnamomum species. Of particular importance are Ceylon cinnamon from Cinnamomum verum and cassia cinnamon from Cinnamomum cassia or related species; they differ in sensory profile, coumarin content and raw-material quality.

Cinnamomum species are evergreen trees or shrubs of the Lauraceae with aromatic bark, leathery leaves and small flowers. Cinnamon is obtained primarily from the dried inner bark of selected species. Cinnamomum verum provides fine Ceylon cinnamon with thin, multilayered quills and a mild, sweet profile. Cinnamomum cassia, Cinnamomum burmannii and Cinnamomum loureiroi are commonly traded as cassia cinnamon or regional cinnamon types and usually have thicker bark pieces and stronger, sharper aroma profiles. Leaf and bark oils are also produced and may differ chemically. The precise species designation is essential for raw-material specifications.

Phytochemistry

Cinnamon bark contains essential oil, phenylpropanoid aroma compounds, procyanidins, mucilages, tannins, resins and other accompanying polyphenolic constituents. Cinnamaldehyde is the principal characteristic aroma compound of the bark. Depending on species, eugenol, cinnamyl acetate, benzaldehyde, linalool and other volatile components may occur. Cassia cinnamon often contains substantially more coumarin than Ceylon cinnamon. Cinnamon leaf oil may be richer in eugenol, whereas bark oil is more strongly characterised by cinnamaldehyde. Composition depends on species, origin, bark age, harvest, drying, storage and oil production. For extracts, coumarin, cinnamaldehyde, polyphenol profile, solvent and standardisation are particularly relevant.

Traditional Uses

Cinnamon is one of the oldest traded spice raw materials. It played an important role in Asian, Arab, Mediterranean and European trade networks and was used as a spice, fragrance, incense material, aroma component and ingredient in traditional preparations. In cuisine and confectionery, cinnamon is widely used for its warm, sweet and spicy aroma. Historically, different Cinnamomum species were often traded under similar names although they differ botanically and chemically. Traditional use of whole or ground bark must be distinguished from concentrated extracts or essential oils.

Current Research

Modern research on Cinnamomum species addresses cinnamaldehyde, coumarin, procyanidins, essential oils, antimicrobial in-vitro models, glucose-metabolism models, aroma stability, authenticity testing and protection against adulteration. Many studies concern cassia cinnamon or inadequately specified raw materials, which limits comparability. Analytically, differentiation between Ceylon and cassia cinnamon and determination of coumarin and volatile aroma profiles are important. Results obtained with isolated cinnamaldehyde, essential oil or high-dose extracts cannot be transferred directly to normal culinary quantities. Authenticity and species identification are central research topics.

Sources

• Plants of the World Online: Cinnamomum Schaeff.; Royal Botanic Gardens, Kew.
• Scientific literature on Cinnamomum verum, Cinnamomum cassia, coumarin and cinnamaldehyde.
• Food and spice analysis literature on Ceylon and cassia cinnamon.