Optimization of ultrasound-assisted extraction of phenolics from Asparagopsis taxiformis with deep eutectic solvent and their characterization by ultra-high-performance liquid chromatography-mass spectrometry

Heqi Gao; Yuxi Wang; Zhiqiang Guo; Yuxin Liu; Qian Wu; Juan Xiao

doi:10.3389/fnut.2022.1036436

Optimization of ultrasound-assisted extraction of phenolics from Asparagopsis taxiformis with deep eutectic solvent and their characterization by ultra-high-performance liquid chromatography-mass spectrometry

Front Nutr. 2022 Nov 17:9:1036436. doi: 10.3389/fnut.2022.1036436. eCollection 2022.

Authors

Heqi Gao¹, Yuxi Wang¹, Zhiqiang Guo¹, Yuxin Liu¹, Qian Wu², Juan Xiao¹

Affiliations

¹ State Key Laboratory of Marine Resource Utilization in South China Sea, Engineering Research Center of Utilization of Tropical Polysaccharide Resources, Ministry of Education/Key Laboratory of Food Nutrition and Functional Food of Hainan Province, School of Food Science and Engineering, Hainan University, Haikou, China.
² Key Laboratory of Fermentation Engineering, Ministry of Education, Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Research Center of Food Fermentation Engineering and Technology, Hubei University of Technology, Wuhan, China.

Abstract

Asparagopsis taxiformis is a significant source of phenolics. Owing to the incessant demand of green extraction procedures for phenolics from A. taxiformis, ultrasound-assisted extraction (UAE) using deep eutectic solvents (DESs) was optimized. Among the tested DESs, betaine-levulinic acid afforded the highest total phenolic content (TPC). Moreover, the optimal extraction conditions elucidated from single-factor and response surface methodologies comprised a 52.41°C ultrasonic temperature, 46.48% water content of DES, and 26.99 ml/g liquid-to-solid ratio. The corresponding TPC (56.27 mg GAE/100 g DW) and antioxidant ability fitted the predicted values. UAE afforded superior TPC and antioxidant abilities with DESs than with traditional solvents. Using UHPLC-MS, seven phenolic acids, 18 flavonoids, and two bromophenols were identified and quantified. DES-UAE afforded the highest phenolic compound number (26) and sum of contents. These results disclose the high extraction efficiency of DES-UAE for A. taxiformis phenolics and provide a basis for the higher-value application of this species.

Keywords: Asparagopsis taxiformis; antioxidant ability; deep eutectic solvent; phenolic; ultrasound-assisted extraction.