| 题名 | 虫草头孢菌丝体多糖的超声辅助提取及其理化性质研究 |
| 作者 | 肖杰 |
| 学位类别 | 硕士 |
| 答辩日期 | 2012-05-28 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 赵兵 |
| 关键词 | 虫草头孢菌丝体多糖 超声辅助提取 大孔树脂 分级纯化 抗氧化活性 |
| 其他题名 | Ultrasonic extraction and physicochemical characteristics of polysaccharides from Cephalosporium sinensis |
| 学位专业 | 生物化工 |
| 中文摘要 | 优化了超声辅助提取（USE）虫草头孢菌丝体多糖的工艺条件，分析了所获粗多糖（USEP）与传统热水提取法（HWE）所获粗多糖（HWEP）在化学成分、形貌及热性质等方面的区别，并对USEP主要多糖组分（USEP40-1，USEP70-1）的红外特性、分子量、单糖组分及其体外抗氧化活性进行了研究，主要结论如下： 响应面法优化了USE的工艺条件：超声功率330 W，提取时间29 min，提取温度62°C。优化条件下，粗多糖得率为3.77 ± 0.017%，较热水提取法的得率(3.07± 0.014%)高23%，且提取时间缩短了5.5小时。经USE及HWE处理后的原料残渣形貌差异显著，揭示了超声提取过程中菌丝体受到剧烈扰动和固液摩擦作用，使提取效率更高。 USEP及HWEP相应化学组分的含量稍有不同。SEM电镜结果表明HWEP的表面形貌为三维多孔状结构，而USEP的精细结构不清晰，且有大面积聚集现象。差示扫描量热分析结果表明USEP在水分蒸发及多糖热解过程中的相转化温度及相变焓均高于HWEP。以上结果表明：超声处理可能引起粗多糖团聚和结晶区增加。此外，USEP及HWEP的分子量分布及自由基清除能力稍有不同。 建立了D113大孔树脂法同时脱除虫草菌丝体粗多糖中色素和蛋白质的工艺。在优化的静态吸附条件下，脱色率为79.5±1.7%，脱蛋白率为82.2±1.7%，多糖保留率为75.0±1.8%。优化的动态吸附条件下，脱色率为85.1±1.9%，脱蛋白率为85.0±2.0%，多糖保留率为80.2±2.2%。50%乙醇盐酸溶液以12 BV/h 流速洗脱1 h后，树脂再生性能良好。 USEP经Sephadex G-100分级纯化，获得两种主要多糖组分（USEP40-1，USEP70-1）。经IR检测，USEP40-1和USEP70-1具有多糖特征吸收峰，但二者在1746 cm-1处吸收峰不同。USEP40-1和USEP70-1的分子量分别为61.4 kDa和25.1 kDa，二者的单糖组成及摩尔比分别为：甘露糖：葡萄糖：半乳糖：鼠李糖：阿拉伯糖= 11.52:5.54:8.75:2.45:2.59和甘露糖：葡萄糖：半乳糖：鼠李糖：阿拉伯糖=11.50:6.74:5.75:4.46:2.39。USEP40-1和USEP70-1的自由基清除能力有一定差异。 |
| 英文摘要 | In the present study, ultrasonic extraction (USE) of polysaccharides from Cephalosporium sinensis was investigated and optimized. The chemical components, morphological and thermodynamic characteristics of ultrasound-extracted crude polysaccharides (USEP) were compared with hot water extracted ones (HWEP). The IR spectra, molecular weight, monosaccharide compositions and in vitro antioxidant activities of major purified fractions of USEP (USEP40-1, HWEP70-1) were systematically studied. Based upon the results of single factor experiment, Box-Behnken experimental design was used to optimize the USE parameters. The optimal conditions of USE were 330 W, 29 min and 62°C with the yield of 3.80%. Under the optimized conditions, the yield of USE was of 3.77 ± 0.017%, which was higher than that of HWE (3.07 ± 0.014%), and the extraction time was reduced from 6 hours to half an hour. SEM images of the extraction residues after extracting USEP and HWEP showed that there were significant differences in size and shape, which revealed that the raw materials experienced intense agitation and friction in USE process, leading to higher extraction efficiency. The images of SEM showed that HWEP had a three-dimensional porous structure with small rings and helical coils, while the delicate structure of USEP was unclear and a large range of aggregation occurred. USEP had an increased transition temperature and enthalpy value for removing moisture and degradation than those of HWEP. Changes in thermodynamic as well as morphological characteristics of USEP might be due to the more compact arrangement in polysaccharides, which was induced by ultrasonic treatment. Slightly differences were found in molecular distribution and in vitro antioxidant activities between USEP and HWEP. D113 resin was selected from 8 resins for its desired decolourization and deprotein effects upon crude Cordyceps polysaccharides solution. Under optimal static absorption conditions, the decolorization rate, deprotein rate and recovery rate of polysaccharides were 79.5±1.7%, 82.2±1.7% and 75.0±1.8%, respectively. Under optimal dynamic absorption conditions, the decolorization rate, deprotein rate and recovery rate of polysaccharides were 85.1±1.9%, 85.0±2.0% and 80.2±2.2%, respectively. When eluted by 1 mol/L HCl (prepared by 50% ethanol solution) with the flow rate of 12 BV/h for 1 h, the resin was regenerated completely. Two major fractions (USEP40-1, USEP70-1) were purified and investigated for IR spectra, molecular weights, monosaccharide compositions and antioxidant activities. IR spectra of USEP40-1 and USEP70-1 were different at around 1746 cm-1. The molecular weights of USEP40-1 and USEP70-1 were 61.4kDa and 25.1 kDa. USEP40-1 and USEP70-1 were composed of D-mannose, D-glucose, D-galactose, L-rhamnose and L-arabinose with molar ratio of 11.52:5.54:8.75:2.45:2.59 and 11.50:6.74:5.75:4.46:2.39, respectively. The free radical scavenging activities of USEP40-1 and USEP70-1 were observed to be different. |
| 语种 | 中文 |
| 公开日期 | 2013-09-25 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1815]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 肖杰. 虫草头孢菌丝体多糖的超声辅助提取及其理化性质研究[D]. 中国科学院研究生院. 2012. |
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