Alpha-cyclodextrin: Enzymatic production and food applications

• Novel α-cyclodextrin glycosyltransferases have increased activity and specificity.
• Recent improvements in the enzymatic production of α-cyclodextrin are reviewed.
• The use of α-cyclodextrin as a natural, soluble dietary fiber is discussed.

This mini-review focuses on the unique properties, enzymatic production, and food applications of α-cyclodextrin, as well as its differences with β- and γ-cyclodextrins. The fermentative production of α-cyclodextrin glycosyltransferase (α-CGTase) is also discussed. More efficient processes for the production for α-cyclodextrin have been developed, including the use of α-CGTases with improved α-cyclodextrin specificity, the addition of appropriate complexing agents, and the simultaneous use of an α-CGTase with another amylase. Compared with other cyclodextrins, α-cyclodextrin has the smallest internal cavity and highest resistance to enzymatic hydrolysis, so it has special applications in food industry, especially as a natural, soluble dietary fiber.