Physico-chemical properties of certain essential oil plants grown in India

Present investigations were conducted on properties of essential oils of different herbal plants of medicinal and aromatic importance. Crop species investigated were Artemisia niligirica, Artemisia annua, Valeriana jatamansi, Citrus sp., Xanthoxylem armatum, Pistacia integerrima and Curcuma zedaria for physico-chemical properties, refractive index, optical rotation, specific gravity and acid value and four genotypes of Melissa officinalis (Lemon balm), one genotype of Cymbopogon flexuosus (Lemon grass) at three harvesting times (June, August and October), two genotypes of Lavendula angustifolia and one genotype of Skimmia anquitilia (Kastur Chara) for chemical composition. (i) The physico-chemical properties of different types of essential oils were specific to crop, species and genotype at a particular age of harvesting of the herbage. (ii) Due to presence of highest content of geraniol, citronellal, citral ‘a’ and ‘b’ and limonene October harvested C. flexuosus was found to be the best from quality of essential oil point of view, (iii) Presence of high amount of major quality attributing components in the essential oil of Lavendula angustifolia cf. IC-273870 proved to be a promising genotype for cultivation and utilization of essential oil production, (iv) In Skimmia anquitilia, 1:8 cineole, linalool, geigrene, linalyl acetate, limonene, geraniol and neral appeared as principal components of essential oil and (v) In Melissa officinalis, most of the quality attributing compounds viz., geraniol, neral, citronellal, C₉-aldehyde, a-pinene etc., were present in higher amount in EC-207383 genotype and geraniol, b-caryophyllene, methyl heptenone and limonene in EC-385375.