Abstract: In the present study, the yield and volatile components of essential oils from lemon peel (Eureka lemon) extracted by a Clevenger apparatus with and without improvement were investigated. The improved Clevenger apparatus was adopted to extract essential oils from peels of five lemon cultivars grown in Guangzhou (Guangdong Province, China). The volatile components were analyzed structurally characterized by using gas chromatography-mass spectrometry (GC-MS). The results indicated that the improved apparatus gave 63.37% higher essential oil yield than the unimproved one, while having no effects on the types of essential oil volatiles. A total of 51, 50, 41, 43 and 42 components were detected from Citrus hystrix, Eureka, Allen Eureka, Femminello and seedless Lisbon, respectively, consisting mainly of alkenes, alcohols, aldehydes and esters along with small amounts of acids and ketones. Alkenes were the most dominant compounds in all the essential oils with the characteristic component D-limonene being the most abundant, followed by β-pinene and γ-terpinene. There were significant differences in the volatile components of peel essential oils from different lemon varieties. Except for 32 common components, each cultivar contained unique volatile components.

Key words: lemon, essential oil, gas chromatography-mass spectrometry (GC-MS)