Japanese SourCitrus Fruits. Part IV. Volatile Compounds of Naoshichi and Tahiti Lime Essential Oils

Abstract

The volatile compounds of naoshichi (Citrus taguma-sudachi Hort. ex Tanaka) and Tahiti lime (Citrus latifolia Tanaka) whole cold-pressed oils were determined by capillary GC and GC-MS. Sixty components were identified in the naoshichi oil, 38 of them for the first time, among which β -sinensal was notable. The oil was constituted mostly of monoterpene (98.2%) and sesquiterpene (1.1%) hydrocarbons, and a minor percentage of oxygenated compounds (0.7%). The major constituents of the naoshichi oil were limonene (90.5%), γ-terpinene (4.2%), myrcene (1.8%), α-pinene (1.0%), trans-β-farnesene (0.8%), decanal (0.3%), β-pinene (0.3%), and terpinolene (0.2%). In the Tahiti lime oil, 76 components were identified, among which isopiperitenone, trans-dodec-2-enol, trans-α-bisabolene, α-cubebene, and β-cubebene have not been previously reported in the lime oil. Monoterpene hydrocarbons (89.9%) formed the main chemical group of the oil, followed by carbonyls (3.8%), sesquiterpene hydrocarbons (2.7%), esters (2.5%), and alcohols (1.0%). The abundant constituents of the lime oil were limonene (52.2%), γ-terpinene (17.0%), β-pinene (13.0%), citral (3.5%), α-pinene (3.2%), sabinene (2.0%), neryl acetate (1.4%), geranyl acetate (1.0%), α-bergamotene (0.8%), and β-bisabolene (0.8%). The components of the two sour Citrus oils are presented, and discussed relative to other Citrus fruits.