Cinnamaldehyde is the component responsible for cinnamon flavor. It is also a potent antimicrobial compound present in essential oils (see M. Friedman, N. Kozukue, and L. A. Harden,J. Agric. FoodChem., 2000, 48, 5702) The GC response of an artificial mixture containing six essential oil components and methyl benzoate as an internal standard is shown in part (a) of the figure.