LAUSR

Abstract Ajowan (Trachyspermum ammi L.) is a highly valued medicinally important seed spice from Apiaceae family, which contains essential oil, exhibiting a chemical composition that can be strongly altered with developmental stages of the inflorescence. In order to investigate the changes of metabolite profile of Ajowan, the inflorescence harvested in ten developmental stages. The oil of each inflorescence stage collected by hydrodistillation and analysed by GC/MS. The essential oil concentrations were in a range of 3.71% (stage 1)–5.08% (stage 8). In this study, fourteen components were identified, which thymol, γ-terpinene, and ρ-cymene comprised between 94% and 96% of the essential oil. The results showed that during the anthesis stages, the thymol percentage in the essential oil of Ajowan was decreased, but the γ-terpinene percentage was increased. Hence, during the fruit ripening stages, the thymol and ρ-cymene percentages were increased but the γ-terpinene percentage was decreased. There was a negative correlation of γ-terpinene, ρ-cymene, and thymol. The results suggested that different harvest stages of Ajowan inflorescence have a significant effect on the essential oil concentration and composition. Furthermore, the anthesis stage was an important turning point of the main component percentage of the volatile oil composition of Ajowan inflorescence.