Essential oil composition of eight starchy Curcuma species

The chemical composition of essential oils from eight underutilized starchy Curcuma species was studied and the components identified by gas chromatography-mass spectrometry (GC/MS). The yield of essential oil in the rhizomes ranged from 0.38 ml in Curcuma aeruginosa to 1.4 ml/100 g fw in Curcuma zedoaria. The compounds 1,8 cineole, camphor, camphene, α-pinene, and β-pinene were present in most of the species. Each Curcuma species was characterized by the presence of unique compounds which varied in concentration from 0.25 to 70%. These included α-fenchene in Curcuma sylvatica, curcumenene in Curcuma malabarica, elemenone in Curcuma rakthakanta, epicurzerenone and curzerene in Curcuma zedoaria, curdione and xanthorhizol in Curcuma aromatica, and β-eudesmol in Curcuma aeruginosa. The different species were grouped on the basis of essential oil composition and a dendrogram consisting of four clusters was constructed. In view of the ambiguity existing in the classification of different Curcuma species, the essential oil composition could be an important tool for species identification and authentication.