Abstract
Compositional changes of Citrus tamurana Hort. ex Tanaka (hyuganatsu) essential oil were analyzed after storage for 1, 3, 6, and 9 weeks at −21, 5, 20, and 30°C. The total amount of oxides increased greatly. The contents of monoterpene alcohols and ketones also increased. The total amount of monoterpene hydrocarbons was unchanged up to 30°C. However, the contents of myrcene, γ-terpinene, and terpinolene decreased, while there was a considerable increase in p-cymene. Among the sesquiterpene hydrocarbons, considerable increases in the (−)-cedrene, γ-elemene, and α-humullene contents were noted in samples stored at 30°C, and the trans-β-farnesene content decreased during storage. The total content of monoterpene alcohols was increased slightly. The content of trans-carveol increased during storage. p-Cymene, trans-carveol, isopiperitone, and limonene oxide contents increased, while γ-terpinene, terpinolene, and citronellal contents decreased significantly during storage. The changes of these compounds during storage can serve as a quality index for hyuganatsu essential oil.
