Olfactory evaluation and untargeted profiling of floral volatiles of fragrant rose cultivars Pusa mahak and its seed parent Century two by HS-SPME-GC × GC-tofms

Abstract

Pusa Mahak is a recurrent flowering and floriferous rose cultivar bearing attractive dark pink coloured flowers with strong outstanding fragrance. Pusa Mahak, a hybrid tea rose, is ideal for garden display and floral arrangements. It was developed by selection from the open-pollinated seedlings of cv. Century Two, a bold and pink coloured blooming rose used for garden display purpose. This study was undertaken to evaluate intensity and likeability of fragrance of the two cultivars based on olfactory evaluation by an untrained panel and to profile the floral volatiles using headspace solid phase microextraction - 2D gas chromatography time of flight mass spectrometry. The fragrance profiles of cvs. Pusa Mahak and Century Two were found to be distinct in the study. Sensory evaluation indicated that cv. Pusa Mahak had stronger fragrance and greater likeability with sweet woody and mild spicy nuances in comparison to the damask floral and green herb like nuances of Century Two. Biochemical evaluation detected 82 compounds (55% terpenoids) in cv. Pusa Mahak and 66 compounds (37% phenylpropanoids/benzenoids) in Century Two. Major components (≥5%) identified in cv. Pusa Mahak, were β-pinene (20%), β-citronellol (14%), 2- phenyl ethyl acetate (9.5%), 2-phenyl ethanol (8.3%), 3, 5-Dimethoxytoluene (7.23%), geranial (7.23%) and α-myrcene (7%). Major constituents of headspace volatile of Century Two were 3, 5-dimethoxytoluene (67%), 2-phenyl ethanol (19%) and theaspirane (4.5%). Difference in fragrance quality and intensity was attributed to the variation in the composition of headspace volatiles and different aroma impressions of specific compounds.