Abstract
The composition of the volatile aroma components was defined in the dried and fresh aerial parts of Sideritis scardica Griseb. from R. Macedonia and S. raeseri Boiss. & Heldr. from R. Macedonia, Albania and Greece. Analysis was made by gas chromatography (GC/FID/MS) equipped with a headspace (HS) sampler. Thirty-two components (15 monoterpenes representing 33.2–62.8% and 17 sesquiterpenes representing 25.2–51.2% of the entire volatiles) were identified as aroma components of dried plant material of S. scardica. Thirty components {14 monoterpenes (19.3–74.2%), 2 alcohols (6.2–38.4%) and 14 sesquiterpenes (18.2–33.5%)} were identified as aroma components in the fresh aerial parts of S. scardica. The predominant components were trans-caryophyllene, β-pinene, α-pinene and 1-octen-3-ol, which were found only in the fresh samples. In the aerial parts of S. raeseri, 43 components were identified in the dried samples {22 monoterpenes (65.7–94.3%) and 21 sesquiterpenes (5.4–27.8%)} and 29 components {15 monoterpenes (77.3–90.7%) and 14 sesquiterpenes (6.3–18.2%)} in the respective fresh samples. Prevailing components in all tested samples of S. raeseri were β-pinene, α-pinene, α-copaene, sabinene and limonene. Only minor differences were revealed in the qualitative composition of the aroma volatiles between the dried and fresh plant material of both species. Furthermore there was almost no difference in the chemical profiles of the aroma compounds between S. scardica and S. raeseri, except for 1-octen-3-ol, which was present only in fresh S. scardica.