Characterization of aroma‐impact compounds in cold‐pressed grapefruit oil using time–intensity GC–olfactometry and GC–MS

Abstract

Abstract Thirty‐eight aroma‐active compounds were detected in commercial cold‐pressed grapefruit oil using a time–intensity GC–olfactometry procedure. Identification of the aroma‐active components was based on the combination of sensory descriptors, linear retention index values from DB‐Wax and DB‐1 columns and GC–MS data. Thirteen flavour components, which had not been previously reported in grapefruit oil, were identified. Compounds with the greatest aroma intensities include: 1,8‐cineole, octanal, dodecanal, trans ‐4,5‐epoxy‐( E )‐2‐decenal, β‐sinensal and nootkatone. The aroma activities of sulphur compounds such as 4‐mercapto‐4‐methyl‐2‐pentanol and methional were surprisingly low and neither of the two putative grapefruit aroma impact compounds, 4‐mercapto‐4‐methyl‐2‐pentanone and 1‐ p ‐menthene‐8‐thiol, was detected. Over 200 volatiles have been reported in grapefruit oil, but only 38 have significant aroma activity and 22 of these can be considered major aroma impact compounds. Copyright © 2001 John Wiley & Sons, Ltd.