Volatile compounds of black cumin ( L.) seeds cultivated in Bangladesh and India.

The compositional analysis of volatile compounds of L. seeds obtained from India and Bangladesh was carried out in this study. Apart from the proportion of volatile compounds, the chemical composition of seeds from both sources were similar. The major volatile compounds in Bangladesh seeds were -cymene (36.35%), thymoquinone (29.77%), α-thujene (12.40%), carvacrol (2.85%), β-pinene (2.41%), limonene (1.64%), methyl linoleate (1.33%) and sabinene (1.18%), contribution of these is 87.93% of the total volatile oil. On the other hand, the major volatile compounds in Indian seeds were -cymene (41.80%), α-thujene (13.93%), thymoquinone (10.27%), methyl linoleate (4.02%), carvacrol (3.65%), β-pinene (2.96%), -limonene (2.11%), 4,5-epoxy-1-isopropyl-4- methyl-1-cyclohexene (1.80%), sabinene (1.50%) and 4-terpineol (1.22%); contribution of these were 83.24% of the total volatile oil. In both seeds, -cymene, thymoquinone, and α-thujene were the major components. Importantly, seeds of Bangladesh contained almost 3-fold thymoquinone compared to Indian seeds. In conclusion, the seeds from Bangladesh contain a higher amount of terpene ketones (29.86%) represented by thymoquinone in comparison to Indian seeds (10.61%); on the other hand, Indian seeds contained a higher amount of terpene hydrocarbons (63.18%) mainly -cymene, compared to Bangladesh seeds (54.53%). This is the first study to report detailed compositional analysis and comparison of L. seeds from Bangladesh and India.