Fill a test tube with β-cyclodextrin to a height of approx. 0.5 cm and clamp the test tube almost horizontally. Place some anhydrous copper sulfate in the top part of the test tube. Heat the test tube. This experiment can also be performed with household sugar and starch by way of comparison.

The white β-cyclodextrin very quickly turns yellow and then black and a yellowish-white mist starts rising. A colorless liquid condenses in the upper section of the test tube and turns the white copper sulfate blue. The same observations are made when the experiment is repeated on starch and household sugar.

Since the thermal decomposition of β-cyclodextrin yields water and carbon, as does the thermolysis of sugars, this experiment can be used to demonstrate that β-cyclodextrin is a carbohydrate.

This is a very simple experiment, which can be used to show that cyclodextrins are carbohydrates, together with the experiments on Hydrolysis of β-Cyclodextrin and Dehydration of β-Cyclodextrin.

Cyclodextrins are produced by the enzymatic degradation of maize starch. The enzymes, from the family of enzymes known as CGTases (cyclodextrin glycosyl transferases), break down the starch molecule into segments, which form cyclic oligosaccharides through ring closure. Due to the helical structure of the starch, the segments formed consist mainly of six, seven and eight glucose units. This yields α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin. The isolation of specific enzymes has made it possible to obtain pure cyclodextrins, so that the elaborate procedure of separating the cyclodextrin material mixture is now no longer required.

Whilst β-cyclodextrin shows rapid thermal decomposition, α-cyclodextrin, used as non-digestible fiber in food, remains stable even on prolonged heating and does not break down initially. For this reason α-cyclodextrin is used as a prebiotic additive in bakery products, for example, where it increases the amount of dietary fiber. It is also used to stabilize low-molecular aromas and some fatty acids. Japan and the USA have approved α-cyclodextrin as a food additive with no restriction on the daily dose. In Germany, however, α-cyclodextrin has not yet been approved as a food additive.