Oxygen introduction during extraction and the improvement of antioxidant activity of essential oils of basil, lemon and lemongrass

Abstract

Essential oil extraction is commonly carried out by using the hydrodistillation method, which is described in official compendia of food quality control and medicinal plants. Despite the widespread use of this method, few studies have evaluated the effect of the atmosphere change during extraction on the composition and antioxidant activity of essentials oils. Therefore, a study of oxygen introduction influence during the extraction of essential oils from basil, lemongrass and lemon by hydrodistillation was performed. Total amount of oxygenated compounds (e.g., linalool, camphor, α-terpineol, neral, geranial, eugenol and α-muurolol) increased for all essential oils extracted under oxygen flow. Antioxidant activity evaluated by using the ORAC method significantly increased (P<0.0001) with oxygen from 618 to 906, 355 to 613 and 72 to 262µmol Trolox g-1 oil for basil, lemongrass and lemon, respectively. Therefore, the simple modification proposed could be considered a suitable alternative to obtain essential oils with higher antioxidant activity.

Chemometric Comparison and Classification of Some Essential Oils Extracted from Plants Belonging to Apiaceae and Lamiaceae Families Based on Their Chemical Composition and Biological Activities

“…It is well known that phenolic compounds act as antioxidants [ 25 , 26 ], but they are not fully responsible for the antioxidant activity of essential oils. In a recent study, Ferreira et al, 2017 [ 7 ] have reported an enhanced antioxidant activity of essential oils rich in oxygenated monoterpenes. In the current study, the level of total phenolics in basil EO was proximate to that found in parsley and lovage EOs; however, its antioxidant activity was approximately 3 times higher.…”

“…Essential oils are aromatic and volatile liquids distilled from different plant materials [ 1 ]. Numerous studies have shown that essential oils possess antioxidant, antibacterial, antifungal, and nematicidal activities, with their chemical compounds being responsible for these properties [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Plant essential oils constituents are mainly grouped in two distinct chemical classes: Terpenoids (monoterpene hydrocarbons, sesquiterpene hydrocarbons, and their oxygenated derivatives) and phenylpropanoids (phenols and phenol ethers) [ 14 ].…”

Chemical Composition, Antioxidant, Antibacterial, and Antibiofilm Activities of Backhousia citriodora Essential Oil

“…These chemical compounds of EO might act individually or synergistically as antioxidants. Several studies have indicated that enhanced antioxidant activity was found in EOs which were rich in oxygenated monoterpenes [ 52 , 53 ]. It has been reported that the antioxidant capacity of oxygenated compounds could be ascribed to the free electrons, due to high oxygenation [ 54 , 55 ].…”