紫荆花中多糖的微波提取工艺优化及其抗氧化活性

在单因素试验的基础上，采用Box-Behnken试验设计和响应面分析法，研究提取时间、微波功率、液料比对紫荆花中多糖提取量的影响，建立影响因素与响应值之间的数学模型，确立最佳提取工艺。同时，以1,1-二苯基-2-三硝基苯肼自由基清除能力、还原Fe3＋能力、羟自由基清除能力验证紫荆花中多糖的抗氧化活性。结果表明，紫荆花中多糖的最佳提取工艺为：提取时间16 min、液料比40∶1（mL/g）、微波功率2 kW。此条件下提取量可达30.81 mg/g。抗氧化实验结果表明，紫荆花多糖有一定抗氧化活性。比较微波和煮沸两种方法提取的紫荆花多糖活性和提取效率，发现微波提取更佳。

Microwave-Assisted Extraction and Antioxidant Activities in vitro of Polysaccharides from Cercis chinensis Bunge Flowers

The microwave-assisted extraction of polysaccharides from Cercis chinensis Bunge flowers was optimized with
the combined use of single-factor method and response surface methodology based on Box-Behnken design. A regression
surface model was developed indicating the effects of three operating parameters on extraction efficiency. The antioxidant
activity of the extracted polysaccharides was evaluated by DPPH, hydroxyl radical scavenging and Fe3+ reducing power
assays. The optimal extraction conditions were determined as a solvent to flower ratio of 40:1 (mL/g), 16 min extraction
time and 2 kW microwave power, resulting in an extraction yield of 30.81 mg/g. Antioxidant tests indicated that the
polysaccharides obtained by microwave-assisted extraction had antioxidant activity higher than that of those extracted by
boiling. Moreover, the former method gave a higher yield of polysaccharides.