Enhancing the extraction of essential oil from Mexican lippia (Aloysia citriodora) leaves obtained by hydro-distillation aided by natural deep eutectic solvents (NADES)

Abstract

Due to the increasing demand for green technologies for the extraction of essential oils, natural deep eutectic solvents (NADES) have emerged as a type of environmentally friendly solvents. This work aimed to study the use of different NADES in combination with microwave pretreatment for intensifying the extraction of Aloysya citriodora (Mexican lippia) essential oil (ACEO), a barely studied plant. The chemical composition (GCMS–) and biological activities (antimicrobial activity, antioxidant activity, and total phenolic compounds) of the obtained oils are reported. The yield of ACEO extracted with NADES increased from 0.10 to 0.21 %. The main compounds of each ACEO were verbenone (28–54 %), limonene (2–10 %), and spathulenol (3–15 %). ACEOs extracted with NADES showed better antimicrobial activity against gram-positive bacteria. The ACEO extracted by Ch:OA reduced 3.6 log CFU/mL against Listeria monocytogenes. Meanwhile, ACEOs extracted by Ch:CA and Ch:OA showed the highest antioxidant activities (27.77–35.95 mg TE/mL of EO), and total phenolic compounds (15.33–17.35 mg GAE/mL of EO). Overall results suggest that using these green solvents aided the extraction method and may represent a study opportunity for extracting natural products without harming the environment, improving the process efficiency through a sustainable and innovative approach, with promising industrial applications.