为实现高粱麸皮多酚的开发应用，该研究利用超声波辅助低共熔溶剂（Deep Eutectic Solvent, DES）法提取高粱麸皮多酚。首先，从16种DESs中筛选提取高粱麸皮多酚得率最高的DES体系，其次，基于单因素试验结果，采用响应面法确定高粱麸皮多酚的最优提取条件，并考察高粱麸皮多酚的抗氧化活性。结果表明，提取高粱麸皮多酚的最佳溶剂为1,3-丁二醇-丙二酸，溶剂摩尔比1:1，含水量20%（V/V），在液料比1:26 g/mL，超声温度47 ℃，超声时间50 min时，高粱麸皮多酚得率为19.47 mg/g，分别是70%（V/V）乙醇和70%（V/V）甲醇提取物的2.21倍和1.68倍。DES提取物对2,2′-联氮-双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基、1,1-二苯基-2-三硝基苯肼自由基、超氧阴离子和羟基自由基的半数抑制浓度分别为105.85、122.94、145.42、146.29 g/mL，均显著低于70%（V/V）乙醇和70%（V/V）甲醇提取物（P<0.05）。多酚含量相同时，DES 提取物的铁离子还原能力显著高于70%（V/V）乙醇和70%（V/V）甲醇提取物（P<0.05）。研究表明，超声辅助DES法能够高效提取具有高抗氧化活性的高粱麸皮多酚，该研究有助于高粱麸皮多酚的绿色、高效提取以及高值化应用。

To use polyphenols from sorghum bran, this study employed ultrasonic-assisted deep eutectic solvent (DES) extraction method. The most efficient DES system for extracting polyphenols from sorghum bran was selected from 16 candidates. Subsequently, based on the results of single-factor experiments, the optimal extraction conditions for sorghum bran polyphenols were determined using the response surface methodology. Finally, the antioxidant activity of the extracted polyphenols for sorghum bran was assessed. The results indicate that the optimal solvent for extracting polyphenols from sorghum bran was 1,3-butylene glycol-malonic acid with a solvent molar ratio of 1:1 and water content of 20% (V/V). Under the conditions of solid-liquid ratio of 1:26 g/mL, ultrasonic temperature of 47 ℃ , and ultrasonic time of 50 min, the extraction yield of sorghum bran polyphenols was 19.47 mg/g, which was 2.21 and 1.68 times higher than that obtained by 70% (V/V) ethanol and 70% (V/V) methanol, respectively. The half maximal inhibitory concentration (IC50) values of DES extract against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) cation radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, superoxide anion, and hydroxyl radical were 105.85, 122.94, 145.42, and 146.29 g/mL, respectively, which were significantly lower than those of the 70% (V/V) ethanol and 70% (V/V) methanol extracts (P<0.05). At equivalent polyphenol concentrations, the ferric reducing ability of plasma (FRAP) value of the DES extract was significantly higher than that of the 70% (V/V) ethanol and 70% (V/V) methanol extracts (P<0.05). These results indicate that the ultrasonicassisted DES extraction method effectively extracts polyphenols from sorghum bran with high antioxidant activity. This research contributes to the green, efficient extraction and high-value application of polyphenols from sorghum bran.

山西农业大学科技创新基金项目（2017YJ34）