Chemical variability of fenugreek essential oil

Fenugreek ( Trigonella foenum-graecum L.) is a famous dicotyledonous aromatic medicinal plant that belongs to the Fabaceae family. The numerous biological activities it exhibits are attributed to the rich variety of primary and secondary metabolites it contains, among them essential oil. It is present not only in the seeds but also in the aerial parts of the plant. Essential oil’s chemical composition differs according to various factors. The methods used for essential oil isolation, such as hydrodistillation, steam distillation, liquid-liquid extraction, solid-phase micro-extraction, static headspace solid-phase microextraction, solvent extraction, secondary distillation, steam distillation of oleoresin, and headspace vacuum entrainment of seeds, have a great impact on its composition. In addition, the time and place of harvest, the maturity of the plant and soil treatment with biofertilizers, and seed pre-treatment such as germination, baking, or microwave heating can also have an influence.