Comparison of Biochemical and Chemical Digestion and Detection Methods for Carbohydrates

Abstract

There is a multitude of chemical and biochemical detection methods for sugars. Which ones would be most practical in an undergraduate laboratory setting? How to best detect non-reducing disaccharides? How to make such lab fun for students to perform? After trying several spectrophotometric methods, it was found that chemical detection by dinitrosalicylic acid and biochemical detection by hexokinase/glucose-6-phosphate dehydrogenase reagent are most appropriate. Sucrose, a non-reducing disaccharide was digested chemically with hydrochloric acid and biochemically with invertase. It was concluded that chemical detection and biochemical detection compliment each other. Chemical digestion method was preferred over the digestion by invertase. These methods were applied for testing the validity of sugar ingredients printed on drink labels as well as the measurement of sugar levels in ripening bananas at two different conditions. The comprehensive comparison of these methods and the detection of sugar concentrations in interesting samples might serve as a basis for an undergraduate chemistry laboratory.