This chapter will describe methods to determine neutral sugars by gas chromatography (GC) of alditol acetate derivatives and quantify uronic acids by a colorimetric assay using the m-hydroxydiphenyl method. Understanding the monosaccharide composition of polysaccharides is crucial for predicting their functionality, such as gelling, solubility, and rheological characteristics. It is also vital for comprehending the mechanisms associated with different physiological effects in the body.