MILK-COAGULATION AND PROTEOLYTIC ACTIVITY OF «GLYECK» — CARPATHIAN ENZYME PREPARATION

• Main Author: A.V. Iukalo
• Format: Article
• Language: English
• Published: National Academy of Sciences of Ukraine and Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine. 2015-04-01
• Series: Biotechnologia Acta
• Subjects: milk-clotting preparation «Glyeck»; milk-clotting activity; proteolytic activity; casein fractions.
• Online Access: http://biotechnology.kiev.ua/images/no2_2015/iukalo.pdf

The purpose of this work was to study milk-clotting and proteolytic properties of preparation «Glyeck». Using Soxhlet method we showed that the preparation possesses a high milk-clotting activity, and this activity doesn't change a lot during the storing process (up to 2 years). This is due to two processes taking place simultaneously: decrease in milk-clotting activity of the preparation and reducing the water content in the preparation. Proteolytic activity of the preparation was investigated by both: the modified Benki method and electrophoresis in polyacrylamide gel alkaline system. Electrophoretically homogeneous fractions of αS1-, β-, and k-caseins were obtained to characterize the specificity of the proteolysis. The specificity of cleavage of casein fractions by «Glyeck» preparation was compared with this one of the rennet enzyme and pepsin. It was found that «Glyeck», rennet enzyme and pepsin actively split k -casein. Preparation «Glyeck» showed low proteolytic activity to αS1- and β -caseins that is typical for purified chymosin. Electrophoretic analysis of proteolysis products of casein fractions confirms the high specificity of «Glyeck» preparation towards k -casein. Casein fractions such as αS1- and β -casein were more resistant to this preparation. The results indicate that preparation «Glyeck» is a natural milk-clotting preparation with high quality and it is mainly consists of protelytic enzyme chymosin.