Selecting multi-enzyme composition and preparation conditions for strong wort

Abstract

Development of sustainable biotechnologies for deep processing of grain raw materials requires effective mechanisms of obtaining strong wort for alcohol production. To provide qualitative characteristics of biochemical composition and rheological properties of strong wort, it is necessary to select optimal enzyme systems and conditions for deep conversion of high-molecular weight polymers of the grain. Previous research has proven the efficiency of carbohydrases for processing grain raw materials. However, there is little evidence on the catalytic effect of phytase, including in combination with other hydrolytic enzymes, on the degree of hydrolysis of polymers in grain raw materials when preparing strong wort. This paper demonstrates the effect of proteases and phytases in a multi-enzyme composition, as well as the conditions of enzymatic processing of raw materials, on the rheological and biochemical parameters of strong wort. Wheat, rye and corn were investigated. The synergism of the combined effect of studied hydrolases, including phytolytic and proteolytic enzymes, contributed to an increase in polymer conversion in this grain raw material and the concentration of soluble dry substances of the wort by 1.5 times. Using the proteases and phytases in the multienzyme composition allowed the concentration of the following components in the wort to be increased: glucose – by 1.2–1.3 times; amine nitrogen – by 1.5–2.2 times; phosphorus ions – by 1.4–4.3 times. Additionally, in the wort samples, the content of amino acids in the free form increased by over 4 times. It is shown that the pretreatment of grain raw materials at a temperature of 80–90ºС for 6 hours and saccharification for 1–2 hours using a complete complex of enzymes containing α-amylase, glucoamylase, xylanase, protease and phytase, allows a strong wort with a dry matter content of over 30% to be obtained. Moreover, a significant decrease in viscosity was noted (particularly for rye wort – by 1.3–1.9 times). Our results confirm the essential role of enzymes exhibiting substrate specificity to protein and phytic polymers in grain raw materials.