Use of the casein hydrolyzed with different proteolytic enzymes in tulum cheese making

The aim of this study is to examine the effect of the addition of casein, hydrolyzed to 10% hydrolysis degree by endoprotease from Bacillus licheniformis and endoprotease/exoprotease mixture from Aspergillus oryzae, on some properties of Tulum cheese. In line with this goal, 6 types of cheese containing 10% hydrolyzed and/or nonhydrolyzed casein in the dry matter were produced and matured for 90 days at 6±1°C. The titratable acidity (as % lactic acid), pH, dry matter, protein, fat, salt, water-soluble protein, ripening index, total free fatty acids (as % oleic acid), lactic acid, and citric acid level of Tulum cheese were found to vary between 0.73-1.43%, 4.21-4.80, 47.71-51.83%, 21.71-25.34%, 2.43-3.61%, 20.06-25.77%, 2.50-8.25%, 9.70-34.88%, 0.66-0.99%, 1.11- 2.36%, and 1168-2700 ppm, respectively. Acetic acid and butyric acid in the samples were below the quantification limit. The number of lactic acid bacteria determined on De Man-Rogosa-Sharpe agar varied between 6.28-8.69 log cfu/g. As a result of sodium dodecyl sulfate polyacrylamide gel electrophoresis, it was observed that casein fractions were hydrolyzed to a certain level in all cheese groups in parallel with the progress of ripening. The cheese containing 10% casein in the dry matter and the cheese containing 5% casein + 5% casein hydrolyzed by endoprotease/exoprotease in the dry matter were most liked by the panelists. In conclusion, it has been observed that casein hydrolyzed up to 10% hydrolysis degree with endoprotease and endoprotease/exoprotease enzymes can be used to reduce the ripening period of Tulum cheese.