Chemical Composition of Peel Essential Oils of Sweet Oranges (Citrus sinensis) from Uganda and Rwanda

The chemical composition of cold-pressed peel essential oils of common sweet oranges (Citrus sinensis [L.] Osbeck) from Uganda and Rwanda were analyzed by GC and GC-MS and a total of 51 and 55 volatile chemical components were identified respectively. The major chemical groups were monoterpene hydrocarbons (94.4 and 97.3 %), terpene alcohols (1.4 and 1.0 %), aliphatic aldehydes (1.6 and 0.8 %) and terpene aldehydes (1.4 % and trace). The main compounds were limonene; 87.9 and 92.5 %, myrcene; 2.4 and 2.0 %, α-pinene; 0.5 and 2.4 %, linalool; 1.2 and 0.9 %, octanal; 1.3 and 0.6 % and decanal, 0.2 %. Some of the compounds present in the Ugandan oil, including iso-amyl acetate, iso-safrole, iso-amyl isovalerate, (E)-sabinene hydrate and methyl caprate were absent in Rwandan oil. The Rwanda Citrus oil contains methyl isobutyrate, α-copaene, myrcenol, neryl acetate, geranyl propionate and perilly alcohol which were not detected in Uganda Citrus oil.