Influence of vegetation on the composition of essential oil from (Melissa officinalis L.)

Lemon balm (Melissa officinalis L.) is a perennial plant of the family Lamiaceae, which is used in folk medicine and the food industry, as well as being processed to obtain essential oil. The aim of the special work is to monitor the influence of vegetation on the composition of the essential oil. The chemical composition of essential oils, obtained by steam distillation from lemon balm cultivated in North-eastern Bulgaria, has been determined. The plants were harvested in two periods of vegetation - the first at the end of June and second - at the end of August 2020. The main components in the oil from the first cut are geranial (26.41%), neral (19.55%), (E)-β-caryophyllene (17.46%), germacrene D (7.86%) and β-citronellal (3.24%). In the oil from the second cut, the main components are geranial (37.26%), neral (28.46%), (E)-β- caryophyllene (6.65%), geraniol (4.72%), and β-citronellal (3.04%). The oil from the second harvest has a high content of the main components of geranial, neral and geraniol and a lower content of (E)-β- caryophyllene and germacrene D. Variations in the amounts are also present in other compounds.