ABSTRACT
The quantitation of mono-, di-, and oligosaccharides from hydrolysis of nonstarch polysaccharides is receiving increasing recognition as an accurate measurement of the non-lignin portion of dietary fiber. High performance liquid chromatography (HPLC) techniques based on silica bonded phase or metal-loaded cation exchange columns with RI detection have been widely used for the determination of mono-, di-, and small oligosaccharides for more than a decade. However, these techniques have proved inadequate for separating the complex mixtures of carbohydrates resulting from the hydrolysis of non-starch polysaccharides (NSP) and for separation of polysaccharides with DP >9. The more recently developed HPAE-PAD technique shows great promise for the determination of neutral sugars and uronic acid constituents derived from NSP since nearbaseline separations are obtained allowing direct quantitation. The HPAEPAD technique has also been successfully applied to the determination of sugar alcohols and the separation of polysaccharides up to DP 60. In this chapter, the basis of the HPAE-PAD technique will be reviewed along with examples of its application to the determination of dietary fiber and complex carbohydrate constituents.
