Essential oils and fatty acids composition of Tunisian, German and Egyptian caraway (Carum carvi L.) seed ecotypes: A comparative study

The present study aims to compare for the first time a Tunisian caraway seed ecotype with German and Egyptian ones regarding their fatty acid and essential oil compositions by using gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) analyses. Results showed that total fatty acid (TFA) content varied from 2.90 to 7.30%, based on dry matter weight (DMW). The Tunisian ecotype exhibited the higher TFA proportion (7.30% DMW) than the two other ones. Petroselinic acid (C18:1n-12) was the major fatty acid in the three ecotypes, with the following proportions: 31.12% in TCE, 30.88 and 29.46% in GCE and ECE, respectively. Moreover, TCE contained a higher unsaturated fatty acid (UFA) proportion (87.86% TFA) than GCE (82.94% TFA) and ECE (80.76% TFA). The essential oil yield (based on dry matter weight) presented significant differences between the three caraway seed ecotypes studied. It is interesting to point out that the highest essential oil yield was observed in TCE (1.41%), followed by ECE (1.21%). In addition, 41 volatile compounds were identified in the seed essential oils of the three caraway ecotypes, the main ones being carvone (61.58–77.35%) and limonene (16.15–29.11%). This study showed that caraway seeds are rich in an unusual fatty acid, the petroselinic one. Additionally, the prevalence of unsaturated over saturated fatty acids is considered to be positive from the nutritional point of view. Consequently, the use of this oil in human dietary and in the alimentary industry seems to be a promising alternative. Besides, caraway seed essential oil obtained from the three caraway ecotypes displayed the same chemotype, namely carvone. This bioactive compound has various applications, as fragrance and flavour, potato sprouting inhibitor, antimicrobial agent and also in the medical field.