Staged immobilized amyloglucosidase and immobilized glucose isomerase in

Abstract

The limitation of an immobilized amyloglucosidase in hydrolyzing thinned starch to afford not more than about 93% glucose with isomaltose levels above about 1.5% can be overcome in a process for converting thinned starch to fructose using four closely coupled reactor stages. The first stage is a saccharification reactor using amyloglucosidase which converts thinned starch to a product containing from 50% to 85% glucose. This product is used in a first stage isomerization reactor, the effluent from which is sent to another saccharification reactor using immobilized amyloglucosidase where hydrolysis is continued until no more than about 6% disaccharides and higher oligosaccharides are present. Where this effluent is used as a feedstock for further conversion of glucose to fructose, it is operationally equivalent to a feedstock containing at least 94% glucose but with isomaltose levels under about 1.5%.