高效液相色谱法测定魔芋精粉中葡甘露聚糖的含量及其单糖组成

目的:建立魔芋精粉中葡甘露聚糖(Konjac glucomannan,KGM)的含量及其单糖组成分析的测定方法。方法:还原单糖用1-苯基-3-甲基-5-吡啉唑酮衍生化后采用反相高效液相色谱法,分段梯度洗脱,检测波长250 nm。通过内标法和外标法的结合对2种单糖的定量进行了方法学研究,同时测定了魔芋精粉中KGM含量。结果:该方法甘露糖在1.001～8.008nmoL线性关系良好(r=0.9994);葡萄糖在1.002～8.016nmoL线性关系良好(r=0.9990),KGM平均回收率为98.1％,相对标准偏差为1.84％,重现性为1.72％,KGM含量为79.5％,其单糖组成为Glc:Man=1:1.51。结论:此方法简便、快速,可同时测定KGM含量及其单糖组成,便于魔芋精粉的质量评价。

The Determination of Konjac Glucomannan in Konjac Refined Powder and Monosaccharide Compositions by HPLC

Objective:To establish a quantitative method for the content determination and monosaccharide composition analysis of Konjac glucomannan(KGM)in Konjac refined powder by pre-column derivatization high performance liquid chromatographic method (HPLC). Method: The two derivatives combined reducing monosaccharides with l-phenyl-3-methyl-5-pyrazolone (PMP) were separated by reverse-phase HPLC using a developed fragment gradient elution process, and monitored by ultraviolet detector at 250 nm. The broad reagent peak of PMP was separated very well from all the PMP-sugars,and good separation was achieved for derivatives of mannose and glucose. The quantitative methods of two reducing monosaccharides were studied by the method combined internal and external standard; while the KGM content in Konjac refined powder was determined. Result: Linearity of glucose was good (r = 0.9990) in range of 1.002-8.016 nmol;while mannose (r = 0.999 4) in range of 1.001-8.008 nmol.The average recovery of this method was 98.1 % , RSD of repeatability was 1.72% . KGM content in Konjac refined powder was 79.5% , ratio of glucose to mannose in KGM was 1:1. 51. Conclusion: This method is a sample, convenient and rapid method that can determine KGM content and analyze monosaccharide compositions in KGM, which will be helpful to quality assessment of Konjac refined powder.