Biomass and Essential Oil Yield and Characterization of 14 Ocimum tenuiflorum Varieties

The use of medicinal herbs has increased exponentially in recent years as Americans search for natural ways to promote health and prevent disease. Holy basil (Ocimum tenuiflorum) is an important medicinal used to reduce stress, regulate metabolism, and reduce inflammation. In this study, essential oil content and composition of O. tenuiflorum varieties were evaluated for commercial production. We selected 14 holy basil varieties from commercial catalogs and the USDA Germplasm systems. Plants were grown in the field, harvested, and biomass recorded before and after drying. We extracted the essential oils by hydrodistillation. We evaluted the essential oils qualitatively by GC-MS and quantitatively by GC-FID. Varieties were compared and ranked for harvestable yield and essential oil content per plant. The top five yielders included both USDA and commercial varieties, including PI288779, Amrita, PI652059, PI652057, and Kapoor. Major compounds identified in the essential oil included eugenol, caryophyllene, β-bisabolene, methyl eugenol, estragole, and β-elemene. Eugenol is one of the most desired compounds in the essential oil, and its content varied significantly amongst varieties. Findings suggest an inverse relationship between biomass yield and essential oil content, and different essential oil chemotypes that should all be considered when choosing a variety for commercial production.