响应面法优化超声辅助低共熔溶剂提取山楂总黄酮工艺

考察超声辅助低共熔溶剂提取山楂总黄酮的效果，优化提取工艺参数。首先制备10种不同组分的低共熔溶剂提取山楂总黄酮，从中筛选出得率最高的低共熔溶剂。然后通过单因素实验，确定低共熔溶剂的含水量和组分比例，并利用响应面法优化超声辅助低共熔溶剂提取山楂总黄酮的提取温度、液料比及超声时间，获得最佳提取工艺。结果显示，含50%水的丙三醇/氯化胆碱（摩尔比3:1）低共熔溶剂是提取山楂总黄酮的最佳溶剂，优化的工艺条件为:液料比42 mL/g、超声时间21 min、提取温度72 °C。在此条件下，山楂总黄酮、芦丁、牡荆素、金丝桃苷、槲皮素的得率分别为7.72%、0.24%、0.33%、0.18%、0.27%，均优于传统的醇提法。在浓度为0.1 mg/mL时，山楂DESs提取物DPPH清除率为86%，高于山楂甲醇提取物，其抗氧化活性增强。因此，超声辅助低共熔溶剂可有效提升山楂总黄酮得率，为山楂资源的开发利用提供科学依据。

Optimization of Ultrasonic-Assisted Deep Eutectic Solvent Extraction of Flavonoids from Crataegus pinnatifida Using Response Surface Methodology

To investigate the extraction effect of total flavonoids from Crataegus pinnatifida by using ultrasonic-assisted deep eutectic solvents, and optimize the extraction parameters. Firstly, ten kinds of deep eutectic solvents (DESs) composed with different components were prepared for extracting total flavonoids of C. pinnatifida, and the DESs with the highest yield were selected. Then, water content and the proportion of each component contained in DESs were screened on the basis of the single factor experiments. Meanwhile, the response surface methodology (RSM) was employed to optimize extraction temperature, liquid-solid ratio and ultrasonic time, and obtain the extraction parameters. As results, glycerol/choline chloride (molar ratio 3:1) DESs containing 50% water was chosen as the optimal extraction solvent, and the optimum extraction parameters were as follow: Ultrasonic time (21 min), liquid-solid ratio (42 mL/g) and extraction temperature (72 ℃). Under the above extraction condition, the yield of total flavonoids, rutin, vitexin, hyperoside, quercetin in DESs extract were 7.72%, 0.24%, 0.33%, 0.18% and 0.27%, respectively, which were superior to the traditional alcohol extraction method. The DPPH radical scavenging rate of DESs extract at 0.1 mg/mL was 86%. Compared with methanol extract, the antioxidant activity of DESs extract was enhanced. Therefore, ultrasonic-assisted deep eutectic solvents extraction method could effectively improve the yield of total flavonoids from C. pinnatifida, and would provide the scientific evidence for the resource development and utilization of C. pinnatifida.