Characterization of aroma volatiles in key lime essential oils (Citrus aurantifolia Swingle)

The most intense aroma volatiles of extracted and distilled oils from the peels of key lime (Citrus aurantifolia Swingle) were identified using gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Over 50 odour-active volatiles were detected in the extracted oil, and over 60 in the distilled oil. Geranial, neral and linalool were found to dominate the lime oil aroma in both oils, which accounted for their fresh, floral citrus-like character. Many simple aldehydes contributed to the aroma of the extracted oil, giving it a characteristic lime tone. The distilled oil contained many new odourants, resulting from the acid-catalysed distillation, which imparted woody, must l spicy and balsamic notes to its aroma. These are C-10 alcohols and ethers and many sesquiterpenes, most of which possess lower odour activity and contribute to the more intense piney aroma of the distilled oil. 7-Methoxycoumarin was found to be one of the more intense odourants in the extracted oil. Caryophyllene oxide and humulene oxide 11 were found to be major odourants in the distilled oil; their intensities varied with the method of analysis of the oil. They contribute a sawdust-like and skunky odour, respectively, to the distilled lime oil. Many sesquiterpenes were found to possess some odour activity. Copyright (C) 2003 John Wiley Sons, Ltd.