Microwave-assisted extraction of phenolic compounds from Euphorbia hirta leaf and characterization of its morphology and thermal stability

ABSTRACT

This study succinctly investigated the impacts of energy-based functions on the total phenolic and physicochemical characteristics of Euphorbia hirta. The results of the orthogonal experimental array gave an optimum microwave condition at 2 min of irradiation time, 400 W of microwave power, 12 mL/g of solvent loading, 40°C of the temperature level, and 50% of ethanol concentration. The results from the thermal stability curves revealed initial 89.96% weight retention (< 100°C) from moisture loss and the potential formation of sixty-six phenolic constituents from the disorientated microstructure (<170°C). The above results established the satisfactory performance of the microwave-reflux extraction method.

KEYWORDS:

• Characterization
• energy density
• Euphorbia hirta
• microwave-reflux extraction
• total phenolic content

Acknowledgements

The author acknowledges the Universiti Sains Malaysia for their financial support for this research work under the Analytical Biochemistry Research Center, Gelugor, Malaysia.

Declaration of interest

The authors declare there is no conflict of interest whatsoever.

Additional information

Funding

This research was financially supported by Universiti Sains Malaysia RUI Grant (Grant number: 1001/CABR/8011045). The authors also acknowledged Analytical Biochemistry Research Centre (Universiti Sains Malaysia) for using the testing facilities.