In enzymology, a difructose-anhydride synthase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are and H<sub>2</sub>O, whereas its product is inulobiose.
This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name of this enzyme class is bis-D-fructose 2',1:2,1'-dianhydride fructohydrolase. This enzyme is also called inulobiose hydrolase.