Loading...
Dielectric constant-based optimization for sustainable extraction of centellosides from Centella asiatica using bio-based solvents
Author(s)
Pakaweerachat, Pattarabhorn
Date Issued
August 1, 2026
Type
Article
Abstract
This study systematically examined the influence of solvent polarity and extraction temperature on the recovery of four major centellosides: madecassoside (MAD), asiaticoside (ASI), madecassic acid (MDA), and asiatic acid (ASA) from Centella asiatica. Extractions were performed using ethanol-water, acetone-water, ethanol-ethyl acetate, and hexane-ethyl acetate mixtures at 30–70 °C, covering dielectric constants (ε = 2–70) that correspond to the polarity range of the selected solvent systems. Extraction yields (mg g⁻¹) are expressed on a dry-weight basis. Ethanol–water mixtures demonstrated the highest efficiency for polar glycosides, yielding 19.6 ± 0.3 mg g⁻¹ dry matter (mg g⁻¹ DM) for MAD and 17.2 ± 0.3 mg g⁻¹ DM for ASI at 70 °C, with temperature effects mainly attributed to enhanced mass transfer and no significant thermal degradation observed. In contrast, aglycones (MDA and ASA) achieved optimal yields (3.3–6.5 mg g⁻¹) in solvents with lower dielectric constants, where solvent composition predominated over temperature effects. Solvent polarity, expressed in terms of dielectric constant, provided a quantitative indicator linking solvent selection to centelloside recovery and solvent-temperature interactions. Ethanol-water systems are recommended for food and nutraceutical applications, while ethyl acetate-ethanol mixtures are suited for cosmetic formulations. This work establishes a polarity-temperature framework for enhancing extraction using bio-based solvents, contributing to more sustainable production of bioactive-rich extracts from C. asiatica for use in food, cosmetic, and pharmaceutical industries.
Citation
Industrial Crops and Products, 250, 2026