R.K. Upadhyay

Stable variety selection over locations and recommendations for rose-scented geranium (Pelargonium graveolens L’ Herit. ex Aiton.)

Abstract Objective: In this study, productivity and essential oil quality of rose-scented geranium (Pelargonium graveolens L’ Herit. ex Aiton.) varieties, namely CIMAP Bio-G-171, CIM-Pawan and Bourbon were assessed and compared in two locations of north India. Methods: A field experiment was conducted to evaluate the productivity, while the chemical composition of the essential oils was assessed by GC-FID and GC-MS. Result: Yields of fresh leaves and essential oil from CIMAP Bio-G-171 were significantly higher (173.64–174.42 q h-1 and 69.93–79.06 l h-1) than those of CIM-Pawan (158.08–160.56 q h-1 and 55.57–64.46 l h-1) and Bourbon (133.34–139.33 q h-1 and 44.19–48.38 l h-1). Major constituents of the oils were citronellol (20.9–39.5%), geraniol (10.9–26.5%), linalool (2.9–14.2%), isomenthone (7.4–9.4%), citronellyl formate (5.5–9.1%) and 10-epi-γ-eudesmol (5.2–9.0%). Conclusion: The essential oil yields and chemical compositions were substantially influenced by variety and location of growing. The variety CIMAP Bio-G-171 showed improvement up to 58.2–63.4% and 22.6–25.8% in essential oil productivity over the existing prevalent varieties, Bourbon and CIM-Pawan, respectively.

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.

Optimization of distillation conditions for better recovery of Acorus calamus L. essential oil

Abstract The comminution and distillation time are two important factors, which affect the essential oil yield and/or composition of aromatic plants significantly. To find out the suitable comminution process and optimum distillation time for isolation of essential oil from Acorus calamus L., an experiment was conducted. The comminuted rhizomes (sliced and powdered) were hydrodistilled for different durations and their yields and compositions were compared. Distillation of uncomminuted rhizome for 8 hours gave 2.37% of essential oil. However, in comminuted rhizomes, yield varied from 2.27 to 6.60% under different distillation durations. The resulting essential oils were analyzed using GC-FID and GC-MS. Twenty-seven constituents, representing 94.7–97.2% of the total oil compositions were identified. Major constituents of the oils were (Z)-asarone (84.8–91.2%), and (E)-asarone (2.5–5.2%). The comminution and distillation time showed noteworthy effect on the essential oil yield; however, they showed no major change on the essential oil composition of A. calamus. It was concluded that powdering of dried rhizomes and effecting distillation for 4 hours are appropriate parameters for extracting maximum essential oil from A. calamus at laboratory scale.

Post harvest storage effect on essential oil content and composition of Cymbopogon distans (Nees ex Steud.) Wats.

Abstract The members of Cymbopogon genus are of commercial importance owing to have essential oils, which are highly prized in flavor and fragrance industries. Cymbopogon distans (Nees ex Steud.) Wats. is an under-explored aromatic member of this genus which is found abundantly wild in western and central Himalayan region. The lemon-scented chemotype of C. distans, domesticated in foothills was studied for post harvest storage under shade and open field conditions. The results revealed that there were no losses in essential oil content up to 15 days of storage (0.46%) under shade conditions. However, in field conditions a loss of 6.52% and 10.87% of essential oil was observed over a fresh herb after 7 days and 15 days of storage, respectively. Major constituents of the essential oil, viz.geranial (20.3–25.9%), neral (13.2–17.5%), geraniol(15.3–18.6%), and geranyl acetate (17.2–23.0%) showed change under post harvest storage. In conclusion, C. distans should preferably be distilled a fresh or it may be stored in shade conditions up to 15 days without any loss of essential oil.