Extraction of Cerasus humilis Polyphenol by the Probe-type Ultrasound Assisted with NADES and Its Enrichment Mechanism and Antioxidant Activity

In this study, probe-type ultrasound assisted natural deep eutectic solvents (NADES) were used for the extraction of Cerasus humilis polyphenols (CHP). The extraction parameters were optimised by single factor and orthogonal experiments, and the optimal resin was selected based on adsorption/desorption capacity. The adsorption mechanism of the resin on CHP was investigated by resin adsorption kinetics and isothermal equilibrium experiments, and the composition and antioxidant activity of CHP were analysed. The results showed that choline chloride and citric acid were the optimal solvents for extracting CHP with a solid-liquid ratio of 1:40 (g/mL), ultrasonic power of 540 W, NADES moisture content of 35% (V/V) and ultrasonic extraction for 20 min. The CHP extraction content reached 491.25 mg/100 g dry weight. AB-8 has favorable adsorption/desorption capacity and desorption rate (80.20%, 57.81% and 46.36%, respectively) and was selected as the optimal resin. The adsorption process is monolayer adsorption, and low temperature is conducive to adsorption. Seventeen polyphenolic compounds, including chlorogenic acid, catechins and epicatechins, were identified from the purified extract by LC-MS². In addition, CHP exhibits strong antioxidant activity with SC₅₀ values of 0.059 mg/mL and 0.032 mg/mL for DPPH and ABTS⁺ radical scavenging, respectively. This study may provide a theoretical basis for the green extraction and application of functional agents in Cerasus humilis.