Detection of galactooligosaccharides with high lactose interference in infant formula using a simple single epimer chromatography

摘要

Robust and more anti-interference enzymatic quantification of galactooligosaccharide (GOS) is important in consumer protection. However, many methods with harsh conditions could hardly separate GOS's hydrolysates galactose from its structurally similar isomer glucose, since each of them has double epimers, especially to determinate a trace of GOS from large amounts of lactose in the food matrix. The investigation was designed to solve the problem by using High Performance Liquid Chromatography with Evaporative Light Scattering Detector (HPLC-ELSD), applying friendly mobile phase and column. Result showed the content of galactose was seldom affected even by a high content of glucose by integrating the peak area of an excellent resolution single epimer. Moreover, the method existed a good linearity and stability (recovery rate at 90.5-105.1%), which met the statutory limit requirement for the quantitative analysis of concentrated GOS in infant formula. It was also helpful for separating and quantifying other sugar or epimers.