ANALYSIS OF GREEN AND YELLOW YUZU PEEL OILS (CITRUS-JUNOS TANAKA) - NOVEL ALDEHYDE COMPONENTS WITH REMARKABLY LOW ODOR THRESHOLDS

Yuzu (Citrus junos Tanaka) is a kind of sour orange, which originated in central China. The fruit has a pleasant and fresh odor and has been used widely as a raw material for vinegar and seasoning in Japan. In general, it is well-known that aldehyde components play an important role of odor in citrus essential oil because of their low odor threshold. Therefore, the aldehydes of yuzu peel oil were isolated and analyzed by GC, GC-MS, and NMR. Twenty-two aldehydes in yuzu peel oil of yellow and green maturity were identified. Three of them, 6-methyloctanal, 8-methylnonanal, and 8-methyldecanal, have not been previously reported to occur in nature. The three novel aldehyhdes were synthesized and discussed in more detail. Further odor distinction between green maturity and yellow maturity is also discussed. © 1990, American Chemical Society. All rights reserved.