Identification of Odor-Active Trace Compounds in Blooming Flower of Damask Rose (Rosa damascena)

The flower scent of the damask rose (Rosa damascena) was studied. Two ultratrace components exhibiting high flavor dilution factors were detected as odor-active compounds via aroma extract dilution analysis (AEDA). One of these had a woody note and was identified as rotundone using multidimensional gas chromatography-mass spectrometry-olfactometry (MD-GC-MS-O), while the other had a citrus note and was identified as 4-(4-methylpent-3-en-1-yl)-2­(5H)-furanone (MPF) by fractionation of a commercial rose absolute from R. damascena. To the best of our knowledge, this is the first study addressing the organoleptic importance of these two compounds in the rose scent. Sensory analysis was conducted to evaluate the effects of rotundone and MPF. Adding 50 μg/kg rotundone and 5 μg/kg MPF to the aroma reconstitute of R. damascena provided it with blooming and natural characteristics. Additionally, the existence of rotundone and MPF in five types of fragrant roses was investigated.