菊糖分子量的高效凝胶过滤色谱检测方法及其在贮藏过程中的变化研究

Inulin Molecular Detection Methods of High-Performance Gel Filtration Chromatography and Changes in Inulin Molecular Weight During Storage

菊芋是一种耐盐抗旱植物,可用于生产菊糖.菊糖具有良好的生物活性,其活性受到聚合度的影响.本研究对比了各项条件,总结得到了一套可以用于测定菊糖相对分子量的高效凝胶过滤色谱(HPGFC)方法:纯水为流动相,0.8 m L/min洗脱,Shodex OHpak SB-804HQ色谱柱检测,柱温控制在30℃,样品进样量为每次20μL,检测器为示差折光检测器(RID),采用Sigma公司生产的右旋糖酐标准品,绘制二次方的标准曲线,检测菊糖的相对分子质量.同时利用确定的凝胶过滤色谱(GFC)方法,观察了种植于海岸带盐碱地的菊芋块茎采收后在贮藏过程中的菊糖分子量的变化,发现在?20℃的贮藏条件下,菊芋中的菊糖不会发生剧烈降解,可长期保存提取分子量相近的菊糖.本研究对分析菊糖的分子性质提供了方法基础,对菊芋的采收贮藏有指导意义.

Jerusalem artichoke is a salt- and drought-resistant plant used for the production of inulin. Inulin has good biological activity, which is affected by its degree of polymerization. In this study, we compared various conditions for standardizing a high-performance gel filtration chromatography （HPGFC） method that can be used to determine the relative molecular weight of inulin. A ShodexTM GPC OHpak SB-804 column was used, with ultrapure water as the mobile phase at a flow rate of 0.8 mL/min. The column temperature was 30℃ and the injection volume was 20 μA differential refractive index detector was used for detection, and dextran standard purchased from Sigma-Aldrich was used as the standard. The standard curve was fit with a quadratic equation to determine the relative molecular weight of inulin. Furthermore, we studied the effect of storage on the molecular weight of inulin. Inulin extracted from Jerusalem artichoke did not degrade sharply under storage conditions of -20℃. This knowledge could be used to preserve Jerusalem artichoke to get inulin with similar molecular weight. Our work provides a method to analyze the molecular weight of inulin, and it is instructive for the harvesting and preservation of Jerusalem artichoke.