Cyclodextrins are produced from starch by means of enzymatic conversion. They are used in food, pharmaceutical, drug delivery, and chemical industries, as well as agriculture and environmental engineering.
Cyclodextrins are composed of 5 or more α-D-glucopyranoside units linked 1->4, as in amylose (a fragment of starch). The 5-membered macrocycle is not natural. Recently, the largest well-characterized cyclodextrin contains 32 1,4-anhydroglucopyranoside units, while as a poorly characterized mixture, at least 150-membered cyclic oligosaccharides are also known. Typical cyclodextrins contain a number of glucose monomers ranging from six to eight units in a ring, creating a cone shape:
α (alpha)-cyclodextrin: 6-membered sugar ring molecule
β (beta)-cyclodextrin: 7-membered sugar ring molecule
γ (gamma)-cyclodextrin: 8-membered sugar ring molecule
α- and γ-cyclodextrin are being used in the food industry. As α-cyclodextrin is a soluble dietary fiber, it can be found as Alpha Cyclodextrin (soluble fiber) on the list of ingredients of commercial products.