Comparative investigation of essential clover flower oils from Austria using gas chromatography flame ionization detection, gas chromatography mass spectrometry, and gas chromatography olfactometry

The essential oils of red and white Austrian clover flowers (Trifolium pratense L. and Trifolium repens L.) were analyzed by GC-FID, GC-MS, and GC-olfactometry (GC-sniffing technique), More than 50 compounds were identified in the samples. The main constituents (concentration higher than 2%) of the investigated samples were maltol (8.2%), linalool (4.2%), 1-phenylethyl alcohol (3.2%), phenol (2.9%), phenylethyl acetate (2.7%), acetophenone (2.4%), and (Z)-3-hexenyl acetate (2.2%) for red clover flowers and maltol (5.3%), linalool (3.8%), phenol (3.6%), phenylethyl acetate (3.3%), and 2-phenylethyl alcohol (2.8%) for white clover flowers. The odor of these samples has been characterized, and a correlation compound/odor impression is given.