响应面法优化藏药红雪茶多糖提取工艺

Optimization Extraction Conditions of Polysaccharide from Tibetan Medicine Lethariella spp. by Response Surface Method

在单因素试验的基础上,采用水浸提法,以水溶性多糖提取率作为响应值,基于Box-Behnken中心组合方法进行三因素三水平的试验设计。根据响应面结果,建立了回归模型,确定红雪茶水溶性糖的最佳提取工艺条件,并对所提取的水溶性多糖进行了体外抗氧化活性研究。研究结果表明,水浸提法红雪茶水溶性多糖的最优提取工艺条件参数为:提取温度82℃,提取时间2 h,料液比1∶20(g/mL);在该条件下,测定红雪茶水溶性多糖的提取率为5.8%。体外抗氧化活性研究表明,红雪茶水溶性多糖对氧自由基(.OH和O2-.)有一定的清除作用,IC50分别为0.504 9mg/mL和1.117 2 mg/mL,并且随着多糖浓度的增加清除率逐渐增强。通过对红雪茶水溶性多糖的提取工艺及抗氧化性评价,为今后开发红雪茶功能性食品和抗氧化剂提供了理论参考。

Based on Box-Behnken center composite design within Design-Expert7.0 sottware and response surface results, the optimal extraction process for water-soluble polysaccharide from Lethariella spp. were determined and a regression model was established. On the basis of single factor tests, using extraction rate of water-soluble polysaccharide as response value, three key factors （extraction temperature, extraction time and solid-liquid ratio） were selected as independent variables and water as extraction solvent. The results showed that the optimal extraction process ofpolysaccharide from Lethariella spp. was obtained as followed： extraction temperature of 82 ~C, extraction time of 2 h and solid-liquid ratio of 1 ： 20 （g/mL）. Under these conditions, the extraction rate of water-soluble polysaccharide from Lethariella spp. was 5.805%. In vitro antioxidant activity studies show that water-soluble polysaccharide from Lethariella spp. had partly scavenging action to hydroxyl radical （. OH） and superoxide radical （02＂）, and IC50 was 0.504 9 mg/mL and 1.117 2 mg/mL, respectively. Meanwhile, the scavenging action increased with the increasing concenlration of water-soluble polysaccharide. Through our study, a theoretical reference was provided for future development ofLethariella spp., such as functional food and antioxidants.