ESSENTIAL OILS FROM SPICES GROWN IN ALBERTA. CARAWAY OIL (CARUM CARVI)

Abstract

The caraway seed (Carum carvi L.) grown in Alberta was steam-distilled for its essential oil. During a 4-yr trial, the two harvests made gave a seed oil yield which averaged 2.65% calculated on a dry weight basis. The oil quality was assessed through analysis by combined TL- and GL-chromatography, and by mass and infrared spectrometry. There were 12 major constituents in the oil, with a corresponding percentage of 93.9%. D(+)-carvone and D(+)-limonene were not less than a total of 87.5% of the oil. There were 23 minor and at least 13 trace constituents. The low amount of benzene-related constituents in the oil was taken as a chemical proof for the correct botanical identity of the plants used in the trial. The oil composition was compared with oils which were imported and used by the domestic food industry. The data showed that the oil used by industry is 7% higher in carvone and 6% lower in limonene, while the other constituents are practically the same. The lower carvone content in Alberta oil was attributed to the fact that the climate of the Prairies permitted the seeds to only partly mature, rather than to an inherent carvone deficiency of the fruit.