Casein Proteolysis in Bioactive Peptide Production: Optimal Operating Parameters

Abstract

Introduction. Public health is gradually deteriorating as a result of unhealthy lifestyle and diet, which triggers allergic reaction to certain foods. Milk and dairy products are rich in biologically active substances, which makes them a good dietary supplement for athletes, diabetic patients, etc. However, this popular food contains allergens, for instance, such proteins as αS1-casein, αS2-casein, β-casein, and κ-casein. Therefore, one of the most urgent tasks of modern food science is to reduce the allergenic properties of casein. Heat treatment is an option, but thermal exposure leads to denaturation and produces new antigenic determinants, e.g. epitopes. Biotechnological processing is a more promising method. It is based on the catalytic properties of proteolytic enzymes. Enzymes make it possible to obtain a protein hydrolyzate with amino acids of various molecular weights. The present research provided the optimal working parameters of casein proteolysis by various enzymes (endopectidases), namely trypsin, chymotrypsin, and thermolysin. Study objects and methods. Casein hydrolysates are casein-based biopeptides, and casein is an accessible and valuable milk protein. Trypsin, chymotrypsin, and thermolysin were used as proteases. The experiment was based on standard methods. Results and its discussion. At 47 ± 2°C and pH 7.5 ± 0.2, the production of low-molecular-weight components of casein hydrolyzate proved feasible when thermolysin was used at a ratio of 1:100 for 24.00 ± 0.05 h, and chymotrypsin and trypsin – at a ratio of 1:25 for 24.00 ± 0.05 h. Conclusion. The resulting casein hydrolysates contain biologically active peptides and can be used in formulations of low-allergy functional dairy products in allergy-friendly, sports, and baby diets.

Keywords

• hydrolysis
• proteolysis
• casein
• proteins
• peptides
• amino acids
• trypsin
• chymotrypsin
• thermolysin
• allergy