**2. Need of fractionation of carbohydrates**

Intensive biochemical characterization of the carbohydrate molecules and their various bioactivities may facilitate an understanding of their importance in human nutrition and may suggest individual carbohydrate structures to target for industrial production [6]. Recently, many studies reveal the biological significance of some carbohydrates and their potential role as nutraceuticals. However, detailed analysis is beneficial for the identification of the specific oligosaccharides responsible for such activities, as the activity may be attributed to one oligosaccharide or even a fraction of oligosaccharides within the entire milk oligosaccharide pool. Extraction and fractionation techniques represent useful tool in the analysis of such carbohydrates from food samples. Thus, it is important to investigate the structure of oligosaccharides to understand the relationship between their structure and biological function.
