Extraction of Lycium Barbarum Pigment by Surfactant-Assisted Deep Eutectic Solvents and Its Antioxidant Activity

The traditional extraction method of Lycium barbarum pigment has some problems, such as long extraction time, large solvent consumption, low extraction efficiency and serious environmental pollution, so it is necessary to develop a new extraction method with shorter treatment time, lower cost, easier operation and environmental friendliness than the traditional method. In this study, the pigment from Ningxia Lycium barbarum was extracted, purified and identified by deep eutectic solvents assisted by surfactant. The pigments from Lycium barbarum from Ningxia were extracted, purified and identified by surfactant-assisted deep eutectic solvents (DES). The maximal pigments extraction rate was obtained under optimal conditions (3% surfactant Tween 20 (v/v), menthol-lactic acid with water content of 50% (molar ratio of 1:4), 1% material-liquid ratio (m/v), the water bath at 30 ℃ for 2.5 h). The pigments extraction rate by surfactant-assisted DES was 6-folds higher than traditional extraction agents (ethanol), and reached 32.09 mg/g. The HPLC detection results showed that the main component of the pigments was corn lutein dipalmitate with 348.861 mg/g. Furthermore, the purified pigments exhibited excellent free radical scavenging activities for DPPH and ABTS⁺, and ·OH radicals, indicating its high antioxidant activity.