HPLC Determination of Fructo-Oligosaccharides in Dairy Products

Abstract

Fructo-oligosaccharides is a natural active substance with excellent physiological functions such as improving the gastrointestinal tract, regulating intestinal flora, etc. It is an important nutrient in infant dairy products. Therefore, it is extremely important to accurately detect fructo-oligosaccharides in infant dairy products. Nowadays, the main methods for detection of fructo-oligosaccharides at home and abroad include high performance liquid chromatography, ion exchange chromatography, mass spectrometry, etc. In this article, a method for the determination of fructo-oligosaccharides in modified milk and infant formula milk powder by high performance liquid chromatography (HPLC) was developed. Fructo-oligosaccharides was extracted by water. Protein was precipitated by acetonitrile. The method was performed on NH2 column, the detector was refractive index detector (RID) and the mobile phase was 70% acetonitrile. Fructo-oligosaccharides content of modified milk was in the range of 20-500mg/100g, the recovery was 80.2%-107.1%. The content of Fructo-oligosaccharides in infant formula milk powder was in the range of 100-500mg/100g, the recovery was 71.9%-95.3%. The quantitative detection limit was 20mg/100g. This method was easily to be operated with a high accuracy and the results indicated that it was suitable for the analysis of fructo-oligosaccharides in modified milk and infant formula milk powder.