title: Volatile constituents of redblush grapefruit (Citrus paradisi) and pummelo (Citrus grandis) peel essential oils from Kenya.
abstract: The volatile constituents of cold-pressed peel essential oils of redblush grapefruit (Citrus paradisi Macfadyen forma Redblush) and pummelo (Citrus grandis Osbeck) from the same locality in Kenya were determined by GC and GC-MS. A total of 67 and 52 compounds, amounting to 97.9 and 98.8% of the two oils, respectively, were identified. Monoterpene hydrocarbons constituted 93.3 and 97.5% in the oils, respectively, with limonene (91.1 and 94.8%), alpha-terpinene (1.3 and 1.8%), and alpha-pinene (0.5%) as the main compounds. Sesquiterpene hydrocarbons constituted 0.4% in each oil. The notable compounds were beta-caryophyllene, alpha-cubebene, and (E,E)-alpha-farnesene. Oxygenated compounds constituted 4.2 and 2.0% of the redblush grapefruit and pummelo oils, respectively, out of which carbonyl compounds (2.0 and 1.3%), alcohols (1.4 and 0.3%), and esters (0.7 and 0.4%) were the major groups. Heptyl acetate, octanal, decanal, citronellal, and (Z)-carvone were the main constituents (0.1-0.5%). Perillene, (E)-carveol, and perillyl acetate occurred in the redblush grapefruit but were absent from the pummelo oil. Nootkatone, alpha- and beta-sinensal, methyl-N-methylanthranilate, and (Z,E)-farnesol were prominent in both oils.
authors.affiliation: Department of Food Science and Technology, Faculty of Agriculture, Jomo Kenyatta University of Agriculture and Technology, Post Office Box 62000-00200, Nairobi, Kenya.
authors.forename: Simon Muhoho
authors.initials: SM
authors.lastname: Njoroge
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koaze
authors.forename: Paul Nyota
authors.initials: PN
authors.lastname: Karanja
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Sawamura
mesh_terms: D002957:Citrus / Q000737:chemistry*; D032083:Citrus paradisi / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D007630:Kenya; D009812:Odorants / Q000032:analysis*; D009822:Oils, Volatile / Q000737:chemistry*; D014835:Volatilization
chemical_list: D009822:Oils, Volatile