Production of Functional Inulin-Type Fructooligosaccharides by an Enzyme from Penicillium citrinum.

We report the production of functional inulin-type fructooligosaccharides such as trisaccharide 1-kestose, O-β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl α-D-glucopyranoside, and tetrasaccharide nystose, O-β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl α-D-glucopyranoside, from sucrose by an enzyme from Penicillium citrinum. Sucrose acted as a fructosyl donor and acceptor for the enzyme. The optimum pH and temperature for the enzymatic reaction were 5 and 50 °C, respectively. The enzyme was stable in the pH range of 4.5-7 and at 50 °C. The maximum concentration of 1-kestose obtained was 110 mg/ml, and the maximum production efficiency was 37.3% after a 48-h reaction. The maximum efficiency of combined fructooligosaccharide (1-kestose and nystose) production was 47.1% after a 72-h reaction. Fructooligosaccharides were therefore successfully produced via a fructosyl transfer reaction catalyzed by an enzyme from P. citrinum.