Total Carbohydrate by Phenol-Sulfuric Acid Method

The phenol-sulfuric acid method is a simple and rapid colorimetric method to determine total carbohydrates in a sample. While the method detects virtually all classes of carbohydrates (mono-, di-, oligo-, and polysaccharides), the absorptivity of the different carbohydrates varies. Thus, unless a sample is known to contain only one carbohydrate, the results must be expressed arbitrarily in terms of one carbohydrate. In this laboratory exercise, the total carbohydrate content of soft drinks and beers is determined with the phenol-sulfuric acid method, using a glucose standard curve. Data generated are used to calculate the caloric content of those beverages.