Hydrolyzes inulin-type beta-(2,1)-fructans, but not beta-(2,1)-linkages in branched fructans. Has low activity against beta-(2,6)-linked fructans. May play a role as a beta-(2,1)-trimmer during graminan biosynthesis. Hydrolysis of terminal, non-reducing (2->1)-linked beta-D-fructofuranose residues in fructans. Inhibited by sucrose. Optimum pH is 4.5-5.5. Inactive above pH 7.5. Optimum temperature is 30-40 degrees Celsius. Belongs to the glycosyl hydrolase 32 family.