响应面法优化超声辅助葛根浸提工艺及浸提液抗氧化活性研究

目的采用响应面法优化超声辅助葛根水浸提的工艺，并比较其浸提液的抗氧化活性。方法采用单因素试验结合响应面法，以葛根总黄酮得率为评价指标，对鲜葛根和干葛根超声辅助水浸提工艺进行优化，并测定比较其浸提液的总黄酮含量和抗氧化活性。结果干葛根浸提最佳工艺为：水料比30:1（mL/g）、超声功率310 W、超声时间38 min；鲜葛根浸提最佳工艺为：水料比4.5:1（mL/g）、超声功率442 W、超声时间39 min；在最佳工艺条件下，干葛根和鲜葛根的葛根总黄酮得率分别为（12.68±0.05）mg/g和（4.36±0.04）mg/g。对于同一种葛根，干葛根提取液总黄酮含量和抗氧化能力均高于鲜葛根（P<0.05）；在同一干或鲜状态下，野葛浸提液的总黄酮含量和抗氧化能力显著大于野生粉葛和栽培粉葛（P<0.01），野生粉葛浸提液的抗氧化能力与栽培粉葛差异不显著（P>0.05）。

Optimization of ultrasonic-assisted extraction technology of Pueraria lobata by response surface methodology and antioxidant activity of extracts

Objective To optimize the ultrasonic-assisted water extraction of Pueraria lobata by response surface methodology and to compare the antioxidant activities of the extracts. Methods Using single factor test combined with response surface methodology, the ultrasonic assisted water extraction process of fresh and dry Pueraria lobata were optimized with the yield of total flavonoids as the evaluation index, and the total flavonoids content and antioxidant activity of the extracts were determined and compared. Results The optimal extraction conditions of dried Pueraria lobata were: Water-solid ratio 30:1 (mL/g), ultrasonic power 310 W, ultrasonic time 38 min. The optimal extraction conditions of fresh Pueraria lobata were: Water-solid ratio 4.5:1 (mL/g), ultrasonic power 442 W, ultrasonic time 39 min. Under the optimal conditions, the yield of total flavonoids in dried and fresh Pueraria lobata was (12.68±0.05) mg/g and (4.36±0.04) mg/g, respectively. For the same kind of Pueraria lobata, the total flavonoids content and antioxidant capacity of the extract of dried Pueraria lobata were higher than those of fresh Pueraria lobata (P<0.05). Under the same dry or fresh conditions, the content of total flavonoids and antioxidant capacity of the extract of Pueraria lobata (Willd.) Ohwi were significantly higher than those of the wild and cultivated Pueraria thomsonii Benth (P<0.01), and the antioxidant capacity of the extract of the wild Pueraria thomsonii Benth was not significantly different from that of cultivated Pueraria thomsonii Benth (P>0.05). Conclusion The selected extraction technology is reasonable and feasible, and the dried Pueraria lobata (Willd.) Ohwi and dried wild Pueraria thomsonii Benth are suitable raw materials for the processing of Pueraria lobata beverage.