Cassia cinnamon as a source of coumarin in cinnamon-flavored food and food supplements in the United States.

Coumarin as an additive or as a constituent of tonka beans or tonka extracts is banned from food in the United States due to its potentially adverse side effects. However, coumarin in food from other natural ingredients is not regulated. "True Cinnamon" refers to the dried inner bark of Cinnamomum verum. Other cinnamon species, C. cassia, C. loureiroi, and C. burmannii, commonly known as cassia, are also sold in the U.S. as cinnamon. In the present study, coumarin and other marker compounds were analyzed in authenticated cinnamon bark samples as well as locally bought cinnamon samples, cinnamon-flavored foods, and cinnamon-based food supplements using a validated UPLC-UV/MS method. The experimental results indicated that C. verum bark contained only traces of coumarin, whereas barks from all three cassia species, especially C. loureiroi and C. burmannii, contained substantial amounts of coumarin. These species could be potential sources of coumarin in cinnamon-flavored food in the U.S. Coumarin was detected in all locally bought cinnamon, cinnamon-flavored foods, and cinnamon food supplements. Their chemical profiles indicated that the cinnamon samples and the cinnamon in food supplements and flavored foods were probably Indonesian cassia, C. burmannii.