Cereal Chem 40:618 - 629.  |  VIEW ARTICLE

Conversion of Starch by Microbial Enzymes for Production of Syrups and Sugars.

L. J. Denault and L. A. Underkofler. Copyright 1963 by the American Association of Cereal Chemists, Inc. 

A new commercial amylogucosidase preparation has low activities of other enzymes, of particular importance being the very low level of transglucosidase. Conversions of corn and potato starches have shown that liquefaction of 30% starch pastes, prior to saccharification of amyloglucosidase, can best be accomplished by using a heat-stable bacterial alpha-amylase at a minimum concentration of 175,000 MW units per lb. of starch, a pH of 5.5 to 7.0, and stepwise heating cycles over the gelatinization range of the starch. Optimum conditions for saccharification of amyloglucosidase have been found to be a temperature of 60C., a pH range of 3.35 to 4.4, and an enzyme concentration of at least 60 units per lb. of starch. Enzyme liquefaction and saccharification give essentially quantitative conversions of starch to dextrose. Acid liquefaction and enzyme saccharification give about 5% lower dextrose yields than the all-enzyme system, with higher quantities of nondextrose sugars, while the acid saccharification procedure gives at least 12% less dextrose than the all-enzyme process.