Bioactive components and bioactivity of essential oils, hydrosol and water steam distillation solvents of lemongrass leaves (Cymbopogon citratus)

Abstract Hydrosol is a by-product of the distillation process which contains water-soluble compounds. Hydrosols are becoming increasingly popular in the cosmetic, pharmaceutical, and food industries. Lemongrass ( Cymbopogon citratus ) is an herbal plant widely used as a flavoring agent in herbal teas, frozen desserts, and meat products. The water extract of lemongrass leaves contains alkaloids, phenolics, tannins, and flavonoids, which have antioxidant and antibacterial properties. This research aims to identify the bioactive components and bioactivity of essential oils, hydrosols, and solvents used in the distillation of lemongrass leaves ( Cymbopogon citratus ). Fresh lemongrass leaves were water steam distilled for three hours. The antioxidant activity of lemongrass leaf essential oil, hydrosols, and solvents was determined using the DPPH assay. The chemical composition of lemongrass leaf essential oil, hydrosol, and solvent was analyzed using GCMS. The GCMS test results showed that the essential oil, hydrosol, and solvent of lemongrass leaves had different chemical components. There are 17 compounds found in the lemongrass leaf essential oil, with 5 major compounds namely E-citral (44.22%), Z-citral (32.78%), β-myrcene (15.66%), trans-4,5-epoxi-carane (3.51%) and geranyl acetate (0.82%). In the hydrosol, 3 compounds were identified, namely isolongifolene (18.81%), epiglobulol (64.09%), and 4,7-Epoxy-1H-isoindole-1,3(2H)-dione (17.10%). One compound, (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene, has been identified in the solvent. The antioxidant activity of hydrosols and solvents is the same as the lemongrass leaf essential oil. The findings of this study suggest that distillation waste in the form of hydrosols and distillation solvents for lemongrass leaves has the potential to be functional ingredients that may have applications in both the food and non-food sectors.