## 4 Discussion
[34] reported that yeast numbers were significantly lower in cheese samples with free and immobilized _L. paracasi_ cells after the ripening period compared to control cheese, indicating that _L. paracasi_ strain provided an antifungal effect on cheese. According to [PERSON] et al. [35], the incorporation of whey cheese with _L. casei_ or _L. bulgarcus_ culture resulted in significantly lower cell loads of staphylococci, coliforms and enterobacteria. It has been proposed that lower pH values and high acidity combined with lower moisture content may have developed an unfavorable environment for spoilage bacteria growth [35]. The growth of spoilage bacteria in foods consists of a global issue affecting the food industry with subsequent impact on the economy and health system. Dairy products are usually susceptible to spoilage due to their high moisture content, nutrient-rich composition, sensitivity to temperature fluctuations, as well as the possibility of contamination during production. A wide range of microorganisms has been indicated for spoilage in dairy products, such as _L. monocytogenes_, _S. aureus_, _Salmonella_ spp. and _Penicillium_ spp. [36,37]. Meanwhile, biopreservation by lactic acid bacteria is gaining a good deal of scientific interest, as they produce metabolites, such as organic acids with antimicrobial activity potential [15,37]. With the intention of eliminating food hazards, the resistance of Katiki Domokou cheese samples fortified with _P. acidilactici_ ORE5 culture to deliberate contamination of _L. monocytogenes_ was investigated. The growth rate of _L. monocytogenes_ was significantly limited in cheese samples with free and immobilized _P. acidilactici_ ORE5 culture, indicating its activity against food-borne pathogens. The study of [PERSON] et al. [38]highlighted the anti-listeria effect of intentionally added lactic acid bacteria in artisanal semi-hard cheese, while [PERSON] et al. [39] reported that _L. brevis_ strains incorporated in yogurt drinks exhibited an antifungal activity. In addition, [PERSON] et al. [40] noted a correlation between yeast and _Listeria_ levels, as increased yeast cell loads may favor the viability of _Listeria_ in Feta cheese by affecting physicochemical characteristics of cheese, leading to more favorable pH values for spoilage growth. Physicochemical characteristics are crucial for the determination of the quality of the cheese, as these parameters affect the sensory evaluation, texture and overall acceptability of the cheese. In this vein, pH values, acidity, water activity and moisture content were evaluated. It has been noted that the samples fortified with _P. acidilactici_ ORE5 culture exhibited lower pH values and, subsequently, higher lactic acid concentrations than the control cheese as the storage continued. According to the literature, studies about functional dairy products have reported similar results attributing them to the production of metabolites of probiotic strains [41]. More specifically, post-acidification was observed in yogurts fortified with _L. casei_ ATCC 393 cells after 7 days of storage, according to [PERSON] et al. [32]. In agreement with moisture content levels detected during storage, [PERSON] et al. [42] reported lower moisture values in curd cheese fortified with immobilized _L. lactis_ cells on raisins, indicating that there is a correlation between pH values and moisture content. More specifically, it has been reported that low pH values (<5.0) in cheese may affect protein-to-protein interactions, resulting in a decreased ability of proteins to interact with water and, subsequently, increased syneresis and lower moisture levels [43]. The sensory evaluation of dairy products significantly determines their quality. Subsequently, the development of a unique profile of aromatic compounds in cheese consists of a challenge for the food industry. According to previous studies, esters, acids, alcohols and carbonyl compounds are considered the most important volatile compounds contributing to flavor development in cheese samples.