The Volatile Composition of Kiyomi Peel Oil (Citrus unshiu Marcov×C. sinensis Osbeck) Cultivated in Korea

The volatile composition of Kiyomi peel oil cultivated in Korea was studied by using gas chromatography and gas chromatography-mass spectrometry. The peel oil from the Kiyomi fruit was prepared by using a cold-pressing extraction method. Among the 65 components quantified in Kiyomi oil, 25 terpene hydrocarbons and 40 oxygenated compounds were identified, with peak weight percentages measuring 94.5% and 4.9%, respectively. Limonene was the predominant compound (87.5%), followed by myrcene (2.4%), sabinene (0.9%), $\alpha$-pinene (0.8%), $\beta$-sinensal (0.8%), (Z)-$\beta$-farnesene (0.7%), neryl acetate (0.6%), valencene (0.5%), $\alpha$-farnesene (0.5%), and $\alpha$-sinensal (0.5%). A unique characteristic of the volatile profile of the Kiyomi oil was the proportion of aldehydes (2.7%), which resulted from the relative abundance of $\alpha$- and $\beta$-sinensal. Another unique characteristic of the Korean Kiyomi oil was its relative abundance of $\beta$-sinensal, (Z)-$\beta$-farnesene, neryl acetate, valencene, $\alpha$-sinensal and nootkatone. Valencene and $\alpha$- and $\beta$-sinensal were regarded as the influential components of Korean Kiyomi peel oil.