Optimization of harvesting and post-harvest drying methods of Ocimum africanum Lour. for production of quality essential oil

ABSTRACT

The influences of cropping seasons, crop maturity stages and wilting period on essential oil composition of Ocimum africanum Lour. var. CIM-Jyoti, grown at foothills agroclimatic conditions of northern India, were studied and compared using gas chromatography–flame ionization detector and gas chromatography–mass spectrometry. Altogether, 28 constituents, forming 91.8–99.1% of the total oil composition, were identified by comparing their retention indices and mass spectral data. The essential oil content was found to vary from 0.38% to 0.66% during different maturity stages with maximal in full bloom stage. Citral (55.0–75.5%), (E)-γ-bisabolene (2.6–9.5%), nerol (1.7–8.9%), geraniol (1.5–6.5%), linalool (1.1–6.0%), β-caryophyllene (0.7–3.2%), α-humulene (0.4–2.7%) and 6-methyl-5-hepten-2-one (≤0.03–2.1%) were identified as the characteristic constituents of the essential oil of O. africanum. Significant variations in the essential oil content and qualitative chemical composition were noticed in different harvesting stages of two cropping seasons.

KEYWORDS:

• Ocimum africanum
• essential oil
• citral
• cropping season

Acknowledgements

Authors are thankful to Council of Scientific and Industrial Research (CSIR), New Delhi, India for financial support, to the Director, CSIR-Central Institute of Medicinal and Aromatic Plants, U.P., India for providing necessary facilities and encouragement.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Authors are thankful to Council of Scientific and Industrial Research (CSIR), New Delhi, India for financial support.