title: Changes of the volatile profile and artifact formation in Daidai (Citrus aurantium) cold-pressed peel oil on storage.
abstract: The chemical changes and artifact formation in daidai (Citrus aurantium L. var. Cyathifera Y. Tanaka) cold-pressed peel oil upon storage at 20, 5, and -21 degrees C for 3, 6, and 12 months were investigated using capillary gas chromatography (GC) and GC-MS. Major changes occurred in the oil stored at 20 and 5 degrees C. No changes were found at -21 degrees C. Monoterpene hydrocarbons decreased from 98.0 to 66.4% upon 12 months at 20 degrees C, while sesquiterpene hydrocarbons and alcohols increased from 0.1 to 2.4% and from 0.3 to 7.9%, respectively. Notable decreases of germacrene D, myrcene, linalyl acetate, and limonene occurred. Prominent increases of cis-carveol, trans-beta-farnesene, trans-p-2,8-menthadien-1-ol, linalool, and beta-caryophyllene were found. Thirty-four artifact compounds constituting 17.0% of the total volatile compounds were formed upon 12 months at 20 degrees C. The artifacts consisted of 13 alcohols (6.0%), five carbonyl compounds (5.3%), seven esters (4.9%), three epoxides (0.4%), four hydrocarbons (0.3%), and two unidentified. The prominent artifact compounds were (+)-carvone, trans,trans-farnesyl acetate, sabinene hydrate, 1-octen-3-ol, cis,cis-farnesyl acetate, and dihydrocarveol acetate. The results could be applied for monitoring and control of the flavor quality of daidai essential oil and related products.
authors.affiliation: Department of Food Science and Technology, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
authors.forename: Simon Muhoho
authors.initials: SM
authors.lastname: Njoroge
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ukeda
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Sawamura
mesh_terms: D016477:Artifacts; D002849:Chromatography, Gas; D002957:Citrus / Q000737:chemistry*; D003080:Cold Temperature; D053138:Cyclohexenes; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D000077222:Limonene; D039821:Monoterpenes / Q000032:analysis; D010938:Plant Oils / Q000737:chemistry*; D012717:Sesquiterpenes / Q000032:analysis; D045788:Sesquiterpenes, Germacrane; D013729:Terpenes / Q000032:analysis; D013997:Time Factors; D014835:Volatilization
chemical_list: D053138:Cyclohexenes; D039821:Monoterpenes; D010938:Plant Oils; D012717:Sesquiterpenes; D045788:Sesquiterpenes, Germacrane; D013729:Terpenes; C074463:linalyl acetate; D000077222:Limonene; C027259:germacrene D