Daidai "Citrus aurantium L[ var[ cyathifera Y[ Tanaka# peel oil was extracted by cold!pressing[ The ~avour components of daidai were quantitatively determined using two internal standards with GC and GCÐMS[ The characteristic ~avour components of daidai were examined by GCÐolfactometry[ The percentages by weight of hydrocarbons "05 compounds#\ esters "01 compounds#\ alcohols "00 compounds# and aldehydes "09 compounds# were approximately 85[3)\ 1[0)\ 9[2) and 0[0)\ respectively[ Geranial\ octyl acetate\ geraniol\ octanal\ cedrol\ cis!limonene oxide\ trans!1!decenal\ linalyl acetate and b!elemol were identi_ed as characteristic ~avour components of daidai[ Terpenes were the major components of daidai peel oil\ but they contributed little to the characteristic ~avour of daidai[ Linalyl acetate and b!elemol had the highest ~avour dilution factors[ The results of the omission test showed geraniol\ octanal\ linalyl acetate and cis!limonene oxide to be the active components of the daidai ~avour[ Copyright Þ 1999 John Wiley + Sons\ Ltd[ KEY WORDS] daidai^Citrus aurantium L[ var[ cyathifera Y[ Tanaka^quantitative analysis^weight percentŝ ni.ng!test^characteristic ~avour^aromagram^GCÐMS^cold!pressed oil^GCÐolfactometry "GCÐO#^omission test