Determination of bioactive peptid production performance with volatile aroma compounds and contribution to proteolysis level in White cheese of some yeasts

In this study, White cheese production was made using yeast species as adjunct in Yarrowia lipolytica NCYC 376 (YL), Saccharomyces cerevisiae NCYC 167 (SC), Debaryomyces hansenii NCYC 2572 (DH) and Kluyveromyces marxianus NCYC 179 (KM) as well as starter cultures (Lactococcus lactis ssp. lactis + Lactococcus lactis ssp. cremoris) and ripened at 7±1 °C for 90 days. The use of yeast in White cheese production was found to be significant (P<0.05) on other composition properties except pH and total protein content. Proteolysis properties of cheeses increased during ripening period. Yeast added was found to be effective on pH 4.6-SN rather than 12% TCA-SN. The use of yeast (especially YL and SC yeasts) showed a significant increase in the amount of TFAA towards the end of ripening. Glu, Ala and Cys were the highest concentrations of free amino acids in cheeses. It was determined that the resistance of β-casein to hydrolization during ripening was higher than αs1-casein. In the peptide profiles of the samples, it was determined that the height of the peaks increased depending on yeast differences (especially DH yeast), rather than formation of new peaks in the ripening process. In White cheese, lactic acid bacteria and yeast counts decreased significantly with ripening time (especially on the 60th day of ripening). Esters and alcohols were the most commonly identified volatile compounds in White cheeses. It was found that Debaryomyces hansenii and Kluyveromyces marxianus were more effective in the formation of alcohol compounds, Yarrowia lipolytica was more effective in the formation of aldehyde and ketone compounds in cheese. A higher ACE-i activity was detected in the cheese-soluble fraction of pH 4.6. An increase in antioxidant activity values were observed with yeast use in cheese samples. Antihypertensive and antioxidant activities of YL and DH samples were found to be higher than the other White cheese samples. When the results of sensory analysis were examined, CC and SC samples were generally liked much more than other than other samples. As a result; yeast cultures (especially YL) were found to contribute significantly to proteolysis, antioxidant activity, ACE-i and sensory properties depending on ripening time in White cheese. It was determined that yeast cultures have potential as adjunct culture in the formation of new products with increased functional properties in dairy products.