Green and Optimum Extraction of Total Polyphenols Content from Mitragyna speciosa Korth. Havil Leaves using Microwave-Assisted Natural Deep Eutectic Solvent Extraction

The current study mainly aims to apply and optimize the microwave-assisted natural deep eutectic solvent extraction (MANDESE) method of total polyphenol content from Mitragyna speciosa (Korth.) Havil leaves using response surface methodology (RSM) and its extraction mechanism using scanning electron microscopy (SEM) imaging. The extraction process was performed using the maceration and MANDESE method. Total polyphenols content was examined using Folin-Ciocalteu reagent and spectrophotometer UV-Vis. The extraction mechanism was performed using SEM imaging. The extraction condition as experimental design variable factors for optimization using RSM included NADES composition ratio, the liquid-solid ratio, extraction time, and microwave power. The results show that the MANDESE with some different combinations of NADES composition is more effective than a maceration. SEM imaging result shows that the levels of damage of cells and cell walls were more severe after extraction. The optimum extraction condition has obtained the NADES composition ratio of 3 g/g (choline chloride/sorbitol) and the liquid-solid ratio of 20 mL/g for 20 min extraction time with 60% Watts microwave power. The scale-up confirmation test was obtained the total polyphenols content of 526.12 µg GAE/g sample. This finding demonstrated the optimum condition of the MANDESE method and performed efficiently, rapidly, safely, and environmentally friendly.