Citral Content in Lemongrass (Cymbopogon citratus) Essential Oil at Early and Delayed Harvesting
Dr. Mala Kumari
Department of Chemistry, S.C. College, Ballia, U.P., India.
E-mail:kumrimala310@gmail.com
The demand for lemongrass (Cymbopogon citratus) is for its high citral content. Early or delayed harvesting of lemongrass affected essential oil and citral (Neral and Geranial) content. The objective of the study was to determine the effects of four maturity stages at harvest of lemongrass on essential oil, chemical composition and citral contents. The plants were harvested at 5.0, 6.0, 7.0 and 8.0 months after planting. After harvesting, the essential oil 3,7-dimethyl-2,6-octadienal (citral) is hydrodistilled from lemon grass in the laboratory, 3,7-dimethyl-2,6-octadienal acetals (citral acetals) are synthesized from citral, used in perfumery, flavour, for fortifying lemon oil and has strong antimicrobial qualities. Infrared spectroscopy (IR) and gas chromatography (GC) were conducted for verification of chemical constitution present in essential oil of lemon grass. Nutritionally, lemon grass is a good source of vitamins A and C, folic acid, magnesium, zinc, copper, iron, potassium, calcium manganese and vitamin E. Chemical composition and citral contents were analysed using gas chromatography-mass spectrometry (GC-MS) analysis. There were significant effects of maturity stages on essential oil and citral contents was found. Lemongrass harvested at 5.0 and 6.0, 7.0 months after planting had significantly higher oil contents than maturity i.e., 8.0 month.
Key words: Infra-red, Gas chromatography, Distillation, Lemon grass, Essential oil, Vitamin E and Antimicrobial activity.