Abstract: This study aimed to optimize the process of extracting crude polysaccharides from Jasminum grandiflorum by water extraction and explore its antioxidant activity. Taking the polysaccharide yield as the index, based on single-factor experiments, the Box-Behnken (BBD) response surface methodology was adopted to optimize the extraction process. The J. grandiflorum polysaccharides (SP) were obtained by removing proteins and small-molecule impurities through the Sevage method and dialysis, and their antioxidant activities were determined. The results showed that the optimal extraction process conditions for crude polysaccharides from J. grandiflorum were a liquid-to-solid ratio of 15 mL·g–1, an extraction temperature of 94 ℃, and an extraction time of 2.5 h. Under these process conditions, the average yield of crude polysaccharides from J. grandiflorum was 12.25%, which was close to the predicted extraction rate of 12.24%. The results of antioxidant activity determination showed that SP had scavenging rates of 80.83% and 69.63% for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals, respectively. In addition, the IC50 values were 2.04 mg·mL–1 and 3.60 mg·mL–1, respectively, indicating its antioxidant activity. In conclusion, the water extraction-alcohol precipitation method is simple, efficient, and suitable for the extraction of SP, which have antioxidant potential.

Key words: Jasminum grandiflorum, polysaccharides, process optimization, antioxidant activity

摘要： 以多糖得率为指标，在单因素实验的基础上，采用Box-Behnken (BBD)响应面法对提取工艺进行优化。通过Sevage法及透析法除去蛋白和小分子杂质，获得素馨花多糖(SP)，并测定其抗氧化活性。结果表明，素馨花粗多糖的最佳提取工艺条件为液料比15 mL·g–1、提取温度94 ℃、提取时间2.5 h。在此工艺条件下素馨花粗多糖平均得率为12.25%，接近预测提取率12.24%。抗氧化活性测定结果显示，SP能够清除1,1-二苯基-2三硝基苯肼(DPPH)自由基和2,2'-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基，IC50值分别为 2.04 mg·mL–1和3.60 mg·mL–1；表明其具有抗氧化活性。综上，水提醇沉法简便高效，适用于素馨花多糖提取；得到的素馨花多糖具有抗氧化潜力，为其后续开发利用奠定理论基础。

关键词: 素馨花, 多糖, 工艺优化, 抗氧化活性