Glucose mixed with citric acid as a catalyst was extruded and polymeri
zed using twin screw extruder with 40 of L/D (length/diameter) ratio a
t 160, 180 and 200 degrees C, where the polymerization yields of gluco
se were 43.9%, 75.0% and 93.7%, respectively. Gel permeation chromatog
raphy of glucose extrudates showed that the higher molecular weight fr
actions increased with extrusion temperature, which also resulted in i
ncreasing hydrodynamic intrinsic viscosity. Glucooligosaccharide and p
olydextrose produced by extrusion of glucose were stable for thermal t
reatments over a wide range of pH3.0-11.0. In addition, a-amylase and
amyloglucosidase treatment did not affect the solution viscosity, indi
cating the random linkages of glucose and thus the potential applicati
ons as dietary fiber. This research clearly demonstrated that the extr
usion reactor can be successfully utilized to produce glucooligosaccha
ride and polydextrose from glucose rapidly and continuously in conjunc
tion with selective control of polymerized composition.