Variation in the rhizome essential oil and curcumin contents and oil quality in the land races of turmeric Curcuma longa of North Indian plains

Twenty-seven accessions of Curcuma longa were grown in the climatic conditions of North Indian plains at Lucknow. Rhizomes harvested from each accession were hydrodistilled for their essential oil. The oil content of rhizomes varied between 0.16% and 1.94% on a fresh weight basis. The essential oil of each accession was evaluated for its major terpenes: β-pinene, p-cymene, α-curcumene, β-curcumene, ar-turmerone, α-turmerone and β-turmerone. The accessions could be classified into two types: (a) those in whose essential oils the sum of the seven major terpenes was in the range 58–79%; (b) those in whose oils this sum was 10–22%. The rhizomes of all the accessions were also evaluated for their curcumin content, which was found to vary from 0.61% to 1.45% on a dry weight basis.