Staged immobilized amyloglucosidase and immobilized glucose isomerase in producing fructose from thinned starch

摘要

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%.