ESSENTIAL OILS FROM SPICES GROWN IN ALBERTA. FENNEL OIL (FOENICULUM VULGARE VAR. DULCE)

Abstract

Annual sweet fennel (Foeniculum vulgare var. dulce Mill.), raised by direct field seeding, was evaluated for its horticultural performance and its oil quality over three consecutive growing seasons. Plant vigor and growth under irrigation and fertilizer treatments were rated only as medium. At harvest the majority of umbels were green, and by the first killing frost at least 50% of the plants were still in bloom. Oil yields for herb and fruit were 1.22 and 1.50%, respectively. Oil quality, as reflected by its major and minor constituents, was determined by combined TL- and GL-chromatography and by mass spectral and infrared analyses. Nineteen constituents were identified in the herb oil and 14 in the fruit oil. This corresponded to 96 and 98% of the total oil content. Trans-anethole, fenchone, estragole and limonene represented 79.2% of the herb and 93.1% of the fruit oil. Oil composition appeared to be constant over the 3 yr. Though the oil quality would be acceptable to the food industry, the low yield obtained suggested that a variety with a shorter growth period would be required before carrying out further feasibility studies on commercial production of fennel on the Prairies.