Seasonal Variations in Essential Oil of Dill: A Three Months Study

Objective: This study aimed to investigate the seasonal variations in the content and chemical composition of dill (Anethum graveolens) essential oils during spring, with a focus on how environmental factors shape their bioactive properties. Theoretical Framework: Essential oils from dill are widely recognized for their nutritional, therapeutic, and culinary benefits. Their biological activities are strongly influenced by the chemical profile, which in turn can be modified by seasonal and environmental conditions. Understanding these dynamics provides a foundation for optimizing essential oil production for food, health, and pharmaceutical applications. Method: Essential oils were extracted from dill harvested at three different times in the spring season. Gas Chromatography–Mass Spectrometry (GC/MS) was employed to identify and quantify the chemical constituents and to track compositional changes across harvests. Results and Discussion: The analysis showed notable shifts in the concentration of compounds such as α-phellandrene, β-phellandrene, dill ether, carvacrol, germacrene D, dill apiole, and phytol. Several of these components increased progressively in later harvests. The diversification of bioactive compounds was linked to changes in environmental factors, including rising temperature, longer daylight hours, and plant maturity. These conditions collectively enhanced the biosynthetic activity of dill, enriching the oils’ chemical complexity and potency. Research Implications: Identifying optimal harvest times enables producers to maximize both yield and bioactivity of dill oils, contributing to the development of functional foods, phytotherapeutics, and health-promoting products. Originality/Value: This research highlights seasonal timing as a critical determinant of essential oil quality. By connecting environmental drivers to phytochemical diversity, it provides practical insights for enhancing the nutritional and therapeutic value of dill essential oils.