Ultrasonic-Assisted and Microwave-Assisted Extraction of Phenolics and Terpenoids from Abelmoschus sagittifolius (Kurz) Merr Roots Using Natural Deep Eutectic Solvents

Tan Phat Vo; Thuy Vy Pham; Thi Ngoc Huyen Tran; Le Thao Vy Vo; Trong Thuc Vu; Ngoc Duyen Pham; Dinh Quan Nguyen

doi:10.1021/acsomega.3c03929

Ultrasonic-Assisted and Microwave-Assisted Extraction of Phenolics and Terpenoids from Abelmoschus sagittifolius (Kurz) Merr Roots Using Natural Deep Eutectic Solvents

ACS Omega. 2023 Jul 31;8(32):29704-29716. doi: 10.1021/acsomega.3c03929. eCollection 2023 Aug 15.

Authors

Tan Phat Vo^{1

2}, Thuy Vy Pham^{1

2}, Thi Ngoc Huyen Tran^{1

2}, Le Thao Vy Vo^{1

2}, Trong Thuc Vu^{1

2}, Ngoc Duyen Pham^{1

2}, Dinh Quan Nguyen^{1

2}

Affiliations

¹ Laboratory of Biofuel and Biomass Research, Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City 700000, Vietnam.
² Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc City, Ho Chi Minh City 700000, Vietnam.

Abstract

This research extracted phenolics and terpenoids from Abelmoschus sagittifolius (Kurz) Merr roots using natural deep eutectic solvent-based novel extraction techniques. Twelve natural deep eutectic solvents (NADESs) were produced for recovering phenolics and terpenoids. Citric acid/glucose and lactic acid/glucose, with a molar ratio of 2:1, were determined as the most appropriate NADESs for extracting phenolics and terpenoids, respectively. Afterward, the proper conditions for NADES-based ultrasonic-assisted and microwave-assisted extraction were investigated. Then, the time and liquid-to-solid ratios of ultrasonic- and microwave-combined extraction methods and the sequence of ultrasound and microwave treatments were examined. The conditions of ultrasonic-assisted extraction were 40 mL/g liquid-to-solid ratio, 40% water content, 30°C, 5 min, and 600 W ultrasonic power for the highest terpenoid recovery at 69 ± 2 mg UA/g dw, while 150 W ultrasonic power was suitable for phenolic recovery at 9.56 ± 0.17 mg GAE/g dw. The conditions of microwave-assisted extraction were 50 mL/g liquid-to-solid ratio, 20% water content, 400 W microwave power, and 2 min to acquire the highest phenolics and terpenoids at 22.13 ± 0.75 mg GAE/g dw and 90 ± 1 mg UA/g dw, respectively. Under appropriate conditions, the biological activities, phenolic content, and terpenoid content of obtained extracts from four extraction methods, including ultrasonic-assisted, microwave-assisted, ultrasonic-microwave-assisted, and microwave-ultrasonic-assisted extraction, were compared to select the most proper method. The conditions of ultrasonic-microwave-assisted extraction were 40 mL/g liquid-to-solid ratio, 5 min sonication, and 1 min microwave irradiation to obtain the highest phenolic and terpenoid contents (27.07 ± 0.27 mg GAE/g dw and 111 ± 3 mg UA/g dw, respectively). Ultrasonic-microwave-assisted extraction showed the highest phenolic content, terpenoid content, and biological activities among the four extraction techniques. The changes in the surface morphology were determined using scanning electron microscopy. This study demonstrated that ultrasonic-microwave-assisted extraction was an effective and sustainable method in food and pharmaceutical industries for recovering phenolics and terpenoids from Abelmoschus sagittifolius (Kurz) Merr.