Screening of Key Aroma Components in Essential Oils from Citrus Peels of Different Cultivars

The aroma components and key aroma components from citrus peels with six different aroma types were analyzed to provide the basis for quality evaluation of citrus peels and development of special aroma citrus essential oils. The volatile components of essential oil from citrus peel were analyzed by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GCMS), and the key aroma components were calculated by relative odor activity value (ROAV). The results showed that 75 volatile compounds were identified from the essential oils of 6 citrus cultivars. The content of monoterpene (73.82%~91.19%) was the highest, followed by alcohols (4.32%~12.63%) and sesquiterpene (1.51%~10.20%), and these components interact to form a unique aroma of citrus peel. There were 23 compounds common in essential oils of six citrus peel, and their contents reached about 80.33%~94.59%. According to the composition of the compounds, the six essential oils can be divided into three types: limonene, limonene/γ-terpene and limonene/3-carene. ROAV analysis showed that linalool was the most important flavor component of six essential oils from citrus peel. In addition, the key aroma components of essential oils from Quzhou, Ziyang, Qingpi, Nanfeng, Jinqiuchatang and Hongmeiren were significantly different, and there were 8, 14, 11, 8, 13 and 18 aroma components, which would play an important role in the unique aroma formation of citrus peel essential oil.