Influence of glucoamylase dosage and hydrolysis time on the dextrose equivalent of highly concentrated glucose syrups of extruded starch

An alternative to the traditional technology of glucose syrups from starch based on multistage processes of water-thermal and enzymatic treatment is the use of thermoplastic extrusion with an integrated biocatalysis system. As part of the development of technology, a study of the influence of hydrolysis factors on the dextrose equivalent of the obtained products of biocatalysis and their rheological properties was carried out. An important aspect of the research is the study of the process of hydrolysis at high substrate concentration of the medium - 50% of dry matter. The principle of processing highly concentrated media in biotechnology has technical and economic prerequisites. It helps to reduce the consumption of heat and energy resources and increases the efficiency of using batch and technology equipment. Mathematical models of the dependence of the dextrose equivalent and the dynamic viscosity of hydrolysates on the dosage of the saccharifying enzyme glucoamylase and the processing time were obtained. The analysis of the obtained models showed the equivalence of the influence of both factors on the studied output parameters. The maximum value of the dextrose equivalent in the experiment was 95, corresponding to a glucoamylase dosage of 12 units of glucoamylase per 1 g of starch and 8 hours of incubation. Varying the glucoamylase dosage from 6 to 12 units and hydrolysis time from 4 to 8 hours allows to obtain products with dextrose equivalent in the range from 38 to 95. A significant decrease in the dynamic viscosity of hydrolysates after 4 hours of hydrolysis to 0.18-0.26 Pa•s relative to the initial values of 2.5-2.6 Pa•s was noted. The obtained models of changes in the degree of hydrolysis and rheology of hydrolysates can be used for obtaining syrups from extruded starch with a given value of the dextrose equivalent varying the levels of input factors.