## 3 Results and Discussion
### Proteolytic and ACE-Inhibitory Activity (%) During Ripening of Dutch-Type Cheese Models  
Results of determinations of the proteolytic and ACE-inhibitory activities in the studied cheese models during their ripening are presented in Figure 2. After one week of ripening, the highest ACE-inhibitory activity was found in the cheese models with the addition of _Lb. acidophilus_ 2499 (Figure 2). In other cases of cheese models, the ACE-inhibitory activity was slightly higher than in the control cheeses (69%), and ACE inhibition ranged from 74 to 79%. The control cheeses were also characterized by the lowest proteolytic activity (0.270). This slightly higher value, reaching ca. 0.305, was determined for the cheese models containing adjunct cultures _Lb. acidophilus_ 2499 and _Lb. delbrueckii_ 490. In turn, the highest proteolytic activity was determined for the cheese models manufactured with the addition of _Lb. rhamnus_ 489 and _Lb. casei_ 2639. Similar dependencies, but with higher values, were observed in cheese models after 3 weeks of ripening, with the highest proteolytic activity being demonstrated in the cheese models with adjunct cultures _Lb. rhamnus_ 489. Figure 1: Initial and overall proteolytic activity of examined _Lactobacillus_ strains (mean values and standard deviations). A: homogenous group initial proteolysis, n = 6; a–d: homogenous groups overall proteolysis, n = 6). One of the main factors affecting the proteolytic activity in cheees is the water content. Water content of the analyzed cheese models (48-49%, data not shown) was higher than the typical water content of Dutch-type cheees (42-45%). This was due to two reasons: firstly, the analyzed cheese models were not subjected to pressing and their brining was relatively short, and secondly, the higher water content of the produced models contributed to greater enhancement of proteolysis under model conditions. After 3 and 5 week storage, a similar ACE-inhibitory activity was observed in the cheees with adjunct cultures, despite the presence of different homogeneous groups in the Tukey tests (HSD). Cheese models with the addition of _Lb. acidophilus_ 2499 were characterized by the best ACE-inhibitory capability among all cheese variants both after 1 week and 3 weeks of ripening. Figure 2: Angiotensin-converting enzyme (ACE) inhibitory activity (%) and proteolysis of water soluble extract (WSE) from Dutch-type cheese models during ripening (mean values and standard deviations). a–c: homogenous groups ACE, n = 6; A–D: homogenous groups proteolysis, n = 6. After 5 weeks of storage, all analyzed cheese models were characterized by a high capability for ACE inhibition, exceeding beyond 90%. Similar ACE inhibition was noted in the cheese models with adjunct cultures of _Lb. acidophilus_ 2499, _Lb. rhamnus_ 489, and _Lb. casei_ 2639, however it was considerably higher than in the control cheese models. The addition of strains from the genus _Lactobacillus_ to cheese models influenced the effectiveness of ACE inhibition because the tested strains contributed to a higher ACE inhibition compared to that achieved in the control cheeses at the end of ripening. The adjunct LAB strains also determined the proteolytic activity of the analyzed cheese models after 5 weeks of their ripening. The lowest proteolytic activity was determined in the cheese models with _Lb. delbrueckii_ 490 and in the control models (Figure 2). A significantly higher activity compared to control cheeses was assayed in the cheese models containing adjunct cultures _Lb. acidophilus_ 2499 and _Lb. casei_ 2639 (ca. 0.460). In turn, the highest activity was determined in the cheese models with the addition of _Lb. rhamnus_ 489, and it was 1.5-fold higher than that determined in the control cheeses. [PERSON] et al. [21] showed an increase in the content of inhibitors within the first 24 weeks of ripening of probiotic and control Cheddar chees, which remained at a similar level within the 12 subsequent weeks.