环糊精是一类广泛应用于食品、医药、化工、农业等领域的环状低聚糖。文中研究了以麦芽糊精为底物,其摩尔质量分布对β-环糊精(-βCD)合成的影响。通过GPC分析,运用Sephacryl 200-HR和Sephacryl 400-HR2种凝胶分析麦芽糊精的摩尔质量分布,通过高效液相色谱法(HPLC)分析其小分子糖组成。结果表明:不同葡萄糖值(DE值)的麦芽糊精具有明显不同的分子组成,随着DE值升高,麦芽糊精分子的分支化程度逐步升高,分子链长减小,小分子糖含量呈上升趋势;生产工艺不同可引起DE值相近的麦芽糊精出现摩尔质量分布的较大差异;麦芽糊精分子组成可影响β-CD的合成,应用适当链长的底物在一定程度上可促进环化反应,链长过长易引起歧化反应,而链长过短则会导致β-CD因耦合反应而降解;β-CD的转化率随麦芽糊精分子分支化程度的升高而降低,重均摩尔质量约在(MW)43 053~18 793 g/mol左右且分支较少的线性麦芽糊精分子可认为是环化反应的最适底物。

The molecular weight distribution of maltodextrins and its relation to the synthesis of cyclodextrinsCyclodextrins(CDs) are cyclic oligosaccharides with a wide range of application in food,pharmaceutical,cosmetic and agricultural industries.In this work,we studied the influence of molecular weight distribution of starch degradations on the synthesis of β-CD.The molecular weight distribution of starch degradations were analyzed by GPC on both Sephacryl 200-HR and Sephacryl 400-HR column.The oligosaccharides in starch degradation were analyzed by HPLC.With the increasing of DE,the contents of low weight polysaccharides with higher multiple branching degree increased.Maltodextrins,which were prepared by different methods,had significantly different molecular weight distribution even if they had similar dextrose equivalent value(DE).In general,the conversion rate of β-CD decreased with DE increasing.The best condition for the substrate is the average molecular weight between 43 053~18 793 g/mol and less branch Maltodextrains.Similar DE with different processing methods can shift molecular weight distribution greatly.The different component of Maltodextrains can affect β-CD production.Starch degradations with appropriate molecular weight and higher linear degree are better for the synthesis of β-CD.