Seasonal Variations in Essential Oil Composition of Immortelle Cultivated in Serbia

Our previous research has proven that the immortelle (Helichrysum italicum) essential oil (EO) grown in Serbia possesses respectable biological potential and desirable composition of volatile compounds with the potential for a wide range of applications in the food, cosmetics, and pharmaceutical industries. Within this study, the impact of seasonal variations (temperature, precipitation, and insolation) during three successive years (2017, 2018, and 2019), on the volatile profile of gamma-curcumene + ar-curcumene immortelle chemotype was determined. Steam distillation was utilized to extract EO from the plant material, followed by chromatographic mass spectrometric analysis revealing 50 volatile compounds. A multiple linear regression model was developed, and principal component analyses were conducted to deliver detailed information regarding the prediction, component profile, and parallel contents of active compounds of the immortelle EO. Under Serbian agro-ecological conditions, with appropriate harvest method, immortelle can achieve two harvests per year: the first in July, and the second in August. The gamma-curcumene + ar-curcumene chemotype usually occurs as the dominant chemotype in the region of the ex-Yugoslavia countries. This chemotype probably developed as an adaptation to climatic conditions, and spring and summer precipitation positively influenced curcumene accumulation in plants. Such a phenomenon was especially noticeable in the first harvest.