γ-cyclodextrin:: A review on enzymatic production and applications

Cyclodextrins are cyclic alpha-1,4-glucans that are produced from starch or starch derivates using cyclodextrin glycosyltransferase (CGTase). The most common forms are alpha-, beta-, and gamma-cyclodextrins. This mini-review focuses on the enzymatic production, unique properties, and applications of gamma-cyclodextrin as well as its difference with alpha- and beta-cyclodextrins. As all known wild-type CGTases produce a mixture of alpha-, beta-, and gamma-cyclodextrins, the obtaining of a CGTase predominantly producing gamma-cyclodextrin is discussed. Recently, more economic production processes for gamma-cyclodextrin have been developed using improved gamma-CGTases and appropriate complexing agents. Compared with alpha- and beta-cyclodextrins, gamma-cyclodextrin has a larger internal cavity, higher water solubility, and more bioavailability, so it has wider applications in many industries, especially in the food and pharmaceutical industries.