Kinetics of Reactions with Amyloglucosidase and their Relevance to Industrial Applications

The two types of intramolecular bonds existing in native starch, the α‐1,4 and the α‐1,6 linkage, are shown to have a largely different free enthalpy of hydrolysis. Hence, on incubation of glucose or a dextrin with an enzyme containing α‐1,4 as well as α‐1,6 degrading activities, a situation finally results in which the isomaltose concentration is higher by a factor of six than the maltose concentration. These observations are, in combination with simple mass action law relationships, applied to the modelling of the degradation of dextrins by the enzyme amyloglucosidase. The model is shown to account for the known transient top in DE (dextrose equivalent) on incubation of dextrins with an amyloglucosidase. Furthermore, increasing the dry solids content of the dextrins solution is shown to have a pronounced influence on the DE versus time curves. The influence of the relative activities of the α‐1,4 and the α‐1,6 degradation activities is discussed. The effect of immobilization on the performance of the enzyme is analyzed on a qualitative base.