Variability in the content and composition of essential oil from lemon balm (Melissa officinalis L.) cultivated in Poland.

Essential oil from a few different population of M. officinalis cultivated in Poland has been investigated. The percentage of essential oil ranged from 0.08 to 0.25 ml/100 g in the leaves and from 0.06 to 0.167 ml/100 g in the herb and was higher in the plant material from experimental patch than that from commercial cultivations. Comparative determinations of the essential oil in fresh and dried material showed slightly higher content of the oil in the fresh one. The analysis of the oil composition has been performed by GC and GC/MS. Great differences in the contents of citral, citronellal, linalool, nerol, geraniol beta-caryophyllene and beta-caryophyllene oxide among the populations has been found. Effect of the harvest time, drying and storage on the composition of lemon balm oil has also been studied.