PRODUCING ENZYMATIC HYDROLYZATE FROM FRESHWATER MOLLUSC <i>DREISSENA POLYMORPHA</i>
Pipelines, mechanisms and hydraulic structures laid on the bottom of freshwater bodies are exposed to massive exposure of fouling organisms - mollusks Dreissena polymorpha . Such fouling hinders the equipment operation and increases the corrosion of materials, besides, utilization of mollusks ( Dreissena polymorpha ) requires financial expenditure. Therefore, to solve the problem, dreissena was suggested to be used as a raw material for producing enzymatic hydrolyzate. The data of the mass-size and chemical composition of the raw materials (dreissena flesh) are presented. During the analysis of the model of a 2-factor experiment (the amount of enzyme preparation and the duration of fermentolysis were taken as factors) there was defined the optimal amount of enzyme (bacterial protease - protozyme). The comparative analysis of a control sample (without adding the enzyme) and enzymatic hydrolyzates of dreissena was carried out. There was stated the increase in protein content (3.7-17.8%), in dry matter (7.0-22.7%), amine nitrogen (446.2-158.6 mg/100 g). The periods of the most intensive increase in the degree of hydrolysis (during the first 2 hours of enzymatic hydrolysis by 2.8% and further 3-4 hours by 1.2%), as well as periods of values stabilization (during 2-3 hours and after 4 hours of enzymatic hydrolysis an increase by 0.6% on average). The change in the optical density of hydrolyzate solutions and their TCA-filtrates has been studied, which helped to compare the degree of protein destruction. There has been presented the technological chart of producing enzymatic hydrolyzates from dreissena with following conditions for fermentolysis: temperature 50 ºС, water ratio 1:1, quantity of enzyme protozyme 0.1% to the mass of blanched dreissena with valves, duration 3-4 hours.