半制备高效液相色谱-离子色谱法检测婴幼儿配方食品中低聚半乳糖的含量

Determination of galactooligosaccharides in infant formula foods by semi-preparative high performance liquid chromatography combined with ion chromatography

目的优化并建立半制备高效液相色谱法-离子色谱法测定婴幼儿配方食品中低聚半乳糖含量的方法。方法以乳粉、特殊医学配方奶粉和液态奶为实验对象,利用半制备高效液相色谱法分别收集婴幼儿配方食品中的二糖和三糖及聚合度(degree of polymerization,DP)3以上的糖,再利用β-半乳糖苷酶水解收集聚合度3及3以上的糖组分,利用离子色谱法测定酶解后的半乳糖和葡萄糖的含量,通过计算得到样品中低聚半乳糖的含量。结果异乳糖、葡萄糖、半乳糖、1,6-β-D-半乳二糖和1,3(4)-β-D-半乳二糖在1.0~30.0μg/mL范围内线性关系良好,相关系数为0.9985~0.9999,回收率为82.80%~87.67%,相对标准偏差≤5%。结论该方法结果准确,能够满足检测要求,且前处理操作简单,便于大批量样品的检测。

Objective To optimize and establish a method for determination of galactooligosaccharides in infant formula by semi-preparative high performance liquid chromatography combined with ion chromatography.Methods Taking milk powder,special medical formula milk powder and liquid milk as experimental objects,disaccharides,trisaccharides and sugars with degree of polymerization(DP)above 3 in infant formula were collected by semi preparative high performance liquid chromatography,the sugar components with polymerization degree of 3 or above were collected byβ-galactosidase hydrolyzed.The content of galactose and glucose after enzymolysis was determined by ion chromatography.The content of galactooligosaccharide in the sample was calculated.Results Isolactose,glucose,galactose,1,6-β-D-galactobiose and 1,3(4)-β-D-galactobiose had a good linear relationship in the range of 1.0-30.0μg/mL.The correlation coefficients were 0.9985-0.9999.The recoveries were 82.80%-87.67%,and the relative standard deviations≤5%.Conclusion The results of this method are accurate and can meet the detection requirements.The pretreatment operation is simple and convenient for the detection of large quantities of samples.