HPLC-ELSD法检测石榴中的游离糖含量

Determination of Content of Free Sugar in Pomegranates by HPLC-ELSD

[目的]建立一种HPLC-ELSD分析方法,测定白皮甜石榴和红酸石榴2个不同品种石榴中的可溶性游离糖。[方法]采用超声水溶解提取石榴的游离糖分,以乙腈-水为流动相,氨基色谱柱,应用HPLC-ELSD测定其中的糖分组成及含量。[结果]当乙腈-水体积比为80∶20时,各游离糖组分分离效果良好。甜、酸石榴中的可溶性游离糖分均为果糖和葡萄糖。果糖的标准回归方程为lnCFru=-14.9440+0.9424lnAFru,线性范围0.18～2.77mg/ml;葡萄糖的标准回归方程为lnCGlu=-14.0600+0.9271lnAGlu,线性范围0.48～7.44mg/ml。白皮甜石榴中果糖和葡萄糖的含量分别为7.58%、6.66%,红酸石榴中的含量分别为3.18%、3.74%。[结论]甜石榴总游离糖含量是酸石榴的2倍,所建立的分析方法对水果糖类的测定具有一定的实际应用价值。

[Objective]An analyzing method of HPLC-ELSD was set up,which could be used to detect the soluble free sugars in sweet fruit of pomegranates（white skin） and sour fruit of pomegranates（ red skin）. [Method]The free sugars in pomegranates were extracted by ultrasonic with water as solution. The components and contents of sugars were detected with mobile phase of acetonitrile-water and an amido chromatographic column. [Result]The components of sugars showed a better separating effect as the volume rate of acetonitrile to water was 80 to 20. The soluble free sugars in sweet and sour pomegranate were fructose and glucose. The standard regression equation of fructose was lnCFru = -14. 944 0 ＋ 0. 942 4 lnAFruwith linear range of 0. 18 -2. 77 mg/ml,while that of glucoses was lnCGlu = -14. 060 0 ＋ 0. 927 1 lnAGlu with linear range of 0. 48 -7. 44 mg/ml. The contents of fructose and glucose in the sweet ones were 7. 58% and 6. 66% ,while those in the sour ones were 3. 18% and 3. 74% ,respectively. [Conclusion]The content of total free sugars in sweet pomegranates was twice as that in sour ones. This method has some application values in analyzing sugars in fruits.