Effect of drying techniques on essential oil yield and their quality of lemongrass [Cymbopogon flexuosus (Nees ex Steud) Wats] cultivars Krishna and CKP-25

Abstract

An experiment was conducted on popularly cultivated two cultivars (cv.Krishna and cv. CKP-25) of Lemongrass (C. flexuous [Nees ex Steud) Wats] at FFDC, Kannauj in August 2015 and replicated in February 2016 to examine the effect on different drying techniques by adopting other parameters. The study recorded different parameters at intervals of 7 days during plantation. Cultivar Krishna was more favourable in herbage yield, oil percentage, and oil yield than cv. CKP-25.The semi-dried condition of CV. Krishna was found to be highest in oil percentage, i.e., 1.5 ± 0.08%, followed by shade and sun-shade-dried oil percentage was found as 1.4 ± 0.07% each, and the most negligible value was by fresh leaves, i.e., 0.7 ± 0.03%, whereas cv. CKP-25 oil percentages in semi-dried and shade-dried were found to be highest at 0.9 ± 0.05% each; sun-shade-dried and fresh leaves were 0.8 ± 0.04% and 0.6 ± 0.03%, respectively. In physical analysis, the value of cv. Krishna showed optical rotation in the ranges of -3.0 to -1.62, a refractive index of 1.4785 to 1.4791 at 27 °C, and a specific gravity of 0.8901- 0.8932 at 27°C. However, cv. CKP-25 showed optical rotation in the ranges of -2.4 to -1.31, a refractive index of 1.4724- 1.4829 at 27 °C, and a Specific gravity of 0.8819- 0.8854. All the values were under the range of BIS standards. In an instrumental analysis of the GLC report, citral content was recorded cv. CKP-25 showed a higher citral content of 83.95% in semi-dried conditions than cv. Krishna of 74.5%. The cv. (Krishna) in sun-shade dried, had 79.88%, followed by shade-dried at 76.83% and fresh leaves at 75.71%. Whereas, in cv. CKP-25, sun-shade-dried 83.24%, shade-dried 82.19%, and freshly harvested leaves showed 76.31% citral content, respectively. Keywords: Citral content, CKP-25, Cymbopogon flexuosus cv. Krishna, Drying methods, Lemongrass, Oil percentage, Physical analysis