Assessment of the antioxidant and ACE-inhibitory activities and some quality characteristics of Kasar cheese produced by probiotic Lactobacillus acidophilus

In this study, four types of Ka & scedil;ar cheese were produced using raw milk (C), starter culture (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) (S), starter culture + probiotic Lactobacillus acidophilus ATCC 4356 (SLA), and probiotic L. acidophilus ATCC 4356 (LA) were produced and ripened at 6 +/- 2 degrees C for 150 days. The physicochemical, microbiological, proteolysis, electrophoretic (Urea-PAGE), ACE-inhibitory, and antioxidant activity analyses of vacuum-packed Ka & scedil;ar cheeses were performed on 5, 30, 60, 90, 120, and 150 days of ripening. During ripening, no significant differences (p > 0.05) were detected in total solids, fat, and protein values of Ka & scedil;ar cheeses. Titratable acidity, water-soluble nitrogen (WSN), ripening index (RI), and electrophoresis results of cheese samples showed an increase while pH values decreased. Also, the degradation products of alpha(s1)-casein were higher than those of beta-casein. The number of probiotic L. acidophilus ATCC 4356 after scalding decreased by an average of 1.57 log cfu/g. However, probiotic bacteria count increased during ripening and maintained their viability. The addition of L. acidophilus ATCC 4356 improved the bioactivity, electrophoresis, titratable acidity, and ripening index results of Ka & scedil;ar cheese. ACE-inhibitory activity of Ka & scedil;ar cheeses increased during ripening and had the highest value on the 150th day of ripening. Furthermore, antioxidant activity of Ka & scedil;ar cheeses increased on the 60th day of ripening and then decreased. Consequently, the combination of probiotic bacteria and starter culture had a positive effect on the physicochemical, microbiological, and proteolytic properties of Ka & scedil;ar cheese.