芽球菊苣根粗多糖提取工艺优化及其体外抗氧化活性和相对分子量分析

薛山; 巩子童; 林靖娟; 郑舒晨

doi:10.13386/j.issn1002-0306.2020060337

芽球菊苣根粗多糖提取工艺优化及其体外抗氧化活性和相对分子量分析

Optimization of Extraction Process of Crude Polysaccharide from Chicory Root of Cichorium intybus L. var. foliosum Hegi, and Analysis of Antioxidant Activity in Vitro and Relative Molecular Weight

摘要

摘要: 目的：以印度芽球菊苣根为原料优化粗多糖的提取工艺，测定其抗氧化性及相对分子量。方法：考察料液比、水浴温度和水浴时间对菊苣根粗多糖得率的影响；采用Box-Behnken结合Matlab分析法优化粗多糖热水浸提法提取工艺；测定所提菊苣根粗多糖体外羟自由基清除能力和还原力；纯化后分析中性糖和酸性糖的平均相对分子量。结果：经过单因素和Box-Behnken设计优化试验，得到最佳提取工艺为：料液比2.74:100 g/mL，水浴温度72 ℃和水浴时间165 min，此时菊苣根粗多糖得率的理论预测值为40.32%，经验证实际值为39.99%±0.43%，与预测值差异不显著（P>0.05）；经Matlab分析，当提取时间取较高值（C=165 min），料液比2.4:100～3.1:100 mL/g，水浴温度70～74 ℃，粗多糖得率可以取得较大值。按照上述最优工艺所提菊苣根粗多糖具备羟自由基清除能力（IC₅₀值为1.36 mg/mL）和Fe³⁺还原力（3 mg/mL对应吸光值0.21），且与浓度呈现正相关。此外，采用高效液相色谱（High Performance Liquid Chromatography，HPLC）测得菊苣中性糖和酸性糖峰型良好，酸性糖峰高且窄表现出较高的纯度，中性糖和酸性糖平均相对分子量分别为10072.07和2388.13 Da。结论：Box-Behnken优化法结合Matlab分析法优化菊苣根粗多糖提取工艺切实可行，所提粗多糖不仅高得率，也兼具良好的体外抗氧化能力，其中，酸性糖纯度较高，中性糖分子量较大。

Abstract: Objective: Using the chicory root of Cichorium intybus L. var. foliosum Hegi from Indian as experimental material to optimize the extraction process of crude polysaccharides from chicory root and determin the antioxidant activity in vitro, as well as the molecular weight. Methods: The effects of solid-liquid ratio, water bath temperature and water bath time on the yield of crude polysaccharide from chicory root were investigated. The Box-Behnken optimization combined with Matlab analysis was used to extract the crude polysaccharides from chicory root by hot water extraction. The hydroxyl free radical scavenging ability and reducing power of crude polysaccharide was determined in vitro. After purification, the average relative molecular weights of neutral sugar and acidic sugar were analyzed. Results: The optimal extraction process by single-factor tests and Box-Behnken design optimization test was obtained as follows: Solid-liquid ratio 2.74:100 g/mL, water bath temperature 72 ℃ and water bath time 165 min. At this time, the theoretical predicted value of extraction yieldof crude polysaccharide from chicory root was 40.32%, while the empirical actual value was 39.99%±0.43%, which had no significant difference with the predicted value (P>0.05). Matlab analysis showed that when the extraction time was higher (C=165 min), the solid-liquid ratio was 2.4:100 ~ 3.1:100 mL/g, and the water bath temperature was 70~74 ℃, the extraction yield of crude polysaccharides could get the higher value. The extracted chicory root polysaccharides had hydroxyl radical scavenging capacity (IC₅₀ value was 1.36 mg/mL) and Fe³⁺reducing power (the absorbance value at 3 mg/mL was 0.21), which all showed a positive correlation with the concentration. In addition, the peaks of neutral sugar and acidic sugar of chicory root measured by HPLC were good, and the acidic sugar peak was high and narrow, which showed high purity. The average relative molecular weights of neutral and acidic sugars were 10072.07 and 2388.13 Da, respectively. Conclusion: The method of Box-Behnken optimization combined with matlab analysis to optimize the extraction process of crude polysaccharide from chicory root was feasible. The extracted crude polysaccharide not only had a high yield, but also had a good antioxidant activity test in vitro. Among the crude polysaccharide from chicory root, the purity of acidic sugar was higher, and the molecular weight of neutral sugar was larger. sugar is larger.