Novel Key Aroma Components of Galbanum Oil

Abstract

Galbanum oil is composed of monoterpenes in large amounts and pyrazines in small amounts. Although the monoterpenes are the main components of galbanum oil, they hardly contribute to the distinct galbanum aroma. The scanty amounts of pyrazines, in contrast, contribute significantly to the aroma. Considering the complexity and potency of the odor, the essential oil was assumed to contain so far not identified compounds with high odor contribution. By the gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis of galbanum oil, fruity-green-balsamic notes were detected at two different retention times. The mass spectra (MS) of the newly discovered notes were elucidated by conducting multidimensional (MD) GC-MS-O. By analyzing the MS data, six chemical structures were proposed: (6E/Z,8E)-undeca-6,8,10-trien-2-one, (6E/Z,8E)-undeca-6,8,10-trien-3-one, and (6E/Z,8E)-undeca-6,8,10-trien-4-one. The compounds were then synthesized in an attempt to match the MS, retention indices (RI), and odor qualities. The MD-GC-MS-O analyses of the candidate compounds led to the identification of the novel key aroma compounds (6Z,8E)-undeca-6,8,10-trien-3-one and (6Z,8E)-undeca-6,8,10-trien-4-one in galbanum oil.

Aroma Character Impact Compounds in Kinokuni Mandarin Orange (Citrus kinokuni) Compared with Satsuma Mandarin Orange (Citrus unshiu)

“…The following compounds were purchased from commercial sources: hexanal, (Z)-hex-3-enal, 1,8-cineole, octanal, (Z)-hex-3-en-1-ol, nonanal, 2-isopropyl-3-methoxypyrazine, acetic acid, citronellal, decanal, (E)-non-2-enal, linalool, undecanal, (E)-dec-2-enal, dodecanal, (E)-undec-2-enal, citronellol, perillaldehyde, (2E,4E)-deca-2,4-dienal, geraniol, (E)-dodec-2-enal, eugenol, thymol, isothymol, indole, -pinene, myrcene, limonene, -terpinene, isoamyl alcohol, oct-1-en-3-one, (E)-hept-2-enal, (E)-oct-2-enal, benzaldehyde, (2E,6Z)-nona-2,6-dienal, 2-methylbutanoic acid, 2-acetyl-2-thiazoline, 2-phenylethanol, 4-hydroxy-2,5-dimethylfuran-3(2H)-one, methyl Nmethylanthranilate and vanillin (Sigma-Aldrich Japan, Tokyo, Japan); -damascenone (Firmenich, Meyrin, Switzerland); a mixture of 2-ethyl-4-hydroxy-5-methylfuran-3(2H)-one and 5-ethyl-4-hydroxy-2-methylfuran-3(2H)-one (Givaudan, Vernier, Switzerland); and tridec-1-ene (Tokyo Chemical Industry Co., Tokyo, Japan). The following compounds were synthesized by the methods reported in the literature: (3E,5Z)-undeca-1,3,5-triene, 26) (3E,5Z,8Z)-undeca-1,3,5,8-tetraene, 27) 6-methylheptanal, 28) 6-methyloctanal, 28) yuzunone ((6Z,8E)-undeca-6,8,10-trien-3-one), 29) yuzuol ((6Z,8E)-undeca-6,8,10-trien-4-ol), 30) (2E)-cis-4,5-epoxydec-2-enal, 31) (2E)-trans-4,5-epoxydec-2-enal, 32) (2E,7Z)-trans-4,5-epoxydeca-2,7-dienal 33) and wine lactone (3,6-dimethyl-3a,4,5,7a-tetrahydro-1-benzofuran-2(3H)-one). 34,35) All reagents and solvents were of analytical grade.…”

First identification of the odour‐active unsaturated aliphatic acid (E)‐4‐methyl‐3‐hexenoic acid in yuzu (Citrus junos Sieb. ex Tanaka)

“…[2] Song et al [3] first reported 46 odour-active compounds that were identified in cold-pressed yuzu peel oil using AEDA. Miyazawa et al [4] recently elucidated that (Z,E)-6,8,10-undecatrien-3-one and (Z,E)-6,8,10-undecatrien-4-ol, determined by AEDA, were new potent odorants contributing to the overall yuzu aroma on the basis of sensory evaluation. Recently, we analysed the volatile oil of yuzu using AEDA, with the result that the new odour-active aldehyde trans-4,5-epoxy-(E,Z)-2,7-decadienal was first identified as an aroma component.…”

Characterization of aroma compounds in the peel extract of Jabara (Citrus jabara Hort. ex Tanaka)

“…The following compounds were synthesized as reported in the literature: (5 Z )‐1,5‐octadien‐3‐one, (3 E ,5 Z )‐1,3,5‐undecatriene, (6 Z ,8 E )‐6,8,10‐undecatrien‐3‐one and (2 E )‐ trans ‐4,5‐epoxy‐2‐decenal …”

“…The following compounds were synthesized as reported in the literature: (5Z)-1,5-octadien-3-one, [10] (3E,5Z)-1,3,5-undecatriene, [11] (6Z,8E)-6,8,10-undecatrien-3-one [12] and (2E)-trans-4,5-epoxy-2-decenal. [13] (3E,5E/Z,8Z)-1,3,5,8-Undecatetraene, 1…”

“…[26] 1,3,5,7-Undecatetraene was also reported to contribute to the green aroma of Yuzu. [27] (6Z,8E )-6,8,10-Undecatrien-3-one has been newly identified as a novel character impact compound in galbanum oil [12] and Yuzu peel oil [16] in 2009. A metallic-smelling odorant (No.…”