Method for producing high solids dextrin adhesives

The present invention relates to an improvement in the alpha-amylase method of hydrolyzing a heated slurry of raw starch into starch fragments, the improvement comprising adding a hydrolytically effective amount of the enzyme, glucoamylase, to the reaction slurry. The present invention further relates to a method for the production of high solids dextrim adhesives from raw starch. In carrying out the invention, an aqueous slurry containing raw starch is subjected to hydrolysis at an elevated temperature by the action of two thermally stable enzymes, alpha-amylase and glucoamylase. Once the viscosity of the reaction slurry is reduced to 1000-2000 centipoise as determined by a Brookfield viscometer at 20 rpm, 100 DEG F., and at 45-55% solids (approximately 2.5 hrs.), the enzymes are then inactivated and the reaction is complete. The rheological properties of the resulting slurry can be adjusted as needed. The present invention is useful because it provides a more direct and economical method for hydrolyzing starch in general, and for producing dextrin adhesives directly from raw starch for use in the high speed paper coating industry in particular.