OPTIMIZATION OF SUNFLOWER HUSK ENZYMOLYSIS PARAMETERS THROUGH USE OF MATHEMATICAL MODELING METHODS

USIKBN

Abstract

The study is focused on optimizing the parameters of the process of enzymatic hydrolysis through the use of mathematical modeling methods. The subject of the study was the husks obtained as a result of sunflower seed hulling. Cellulolytic, β-glucanasic, xylanasic and glucoamylasic enzyme preparations produced by Sibbiopharm Production Association, OOO [Limited Liability Company] (city of Berdsk) and Biopreparat Trading House, OAO [Open Joint-Stock Company] (city of Moscow) were used in the process of enzymolysis, namely Cellolux-A, β-glucanase-CL, Cellulase, and Xylanase. During the experiment, the sunflower husks were subjected to alkaline delignification in advance, then mixed with water at a 1:5 ratio. Upon introducing the enzyme preparations, the resulting suspension was maintained at the temperature of 50 °С for 20 hours, with samples drawn every 4 hours. After centrifugation the supernatant fluid was filtered and used to determine the concentration of reducing agents. When setting up the four-factor experiment (2⁴ full factorial experiment), the following optimization criteria were selected: hydrolysis duration and enzymatic preparation activity. Based on the results of a series of experiments, a linear regression equa­tion which described the processes of reducing agent accumulation, with both factors mentioned above in co-operation, was deduced. The resulting mathematical model was shown to be adequate by passing the F‑test and was tested experimentally. Solving the regression equation allowed us to determine the duration of hydrolysis, amounting to 20 hours, and the level of enzymatic preparation activity was found to be 75 u/g. Given the factor ratios, the amount of reducing agents was expected to reach 28.19 g/l, actually amounting to 28.01 g/l.