## 4 Discussion
Some authors [67; 68; 69] claim that LAB strains show the antioxidant activity, which is why the high value of the oxidation-reduction potential can be explained by the high microbiological activity of the LAB strains and their enzymatic capacity. In the tested cheeses, no additional substances were used to influence the oxidation processes and the high values of the redox potential testify to the superiority of the oxidation reaction processes. The oxidation-reduction potential modifications can affect both the microbiological quality (biological activity of non-starter lactic acid bacteria) and the sensorial properties (synthesis and/or stability of aroma compounds) of cheeses [70]. The biochemical changes that occur during cheese maturation can be divided into primary metabolic changes such as glycolysis, lipolysis and proteolysis, followed by secondary biochemical changes such as fatty acid and amino acid metabolism, which play an important role in the production of secondary metabolites, including compounds responsible for the flavor bouquet [62]. The composition of cheese samples prepared in this study was typical and comparable to others [50; 70; 71; 72]. Goat's milk contains slightly less lactose than cow's milk (goat's milk 4.1-4.5% of lactose, cow's milk 4.6-4.7% of lactose). Most of the lactose is found in whey, which is the liquid that is separated from the solid cheese curd during the cheese-making process. The longer the cheese has been aged, the less lactose will remain in the final product [73]. In our study, no lactose was found in the cheese samples. During the maturation process, protein and fat are continuously broken down. Casein is first hydrolyzed to long chain peptides which are then broken down into short chain peptides. Some of the casein eventually breaks down into amino acids and volatiles. When dispersed into small fat globules, the large fat globules are further broken down into ketones, aldehydes and lactones, which break down into volatile substances and free fatty acids [74]. In the present study, the main fatty acids present in the tested acid-rennet cheeses were palmitic C16:0, oleic C18:1 cis9, stearic C18:0 and myristic C14:0, which were also observed in the studies by [PERSON] et al. [75]. It should also be underlined that there was a significant increase in omega-3 and in the cholesterol content in all samples after storage was denoted. Similar results were obtained by [PERSON] et al. [76]. On the other hand, much higher values of the cholesterol content were obtained in the studies by [PERSON] et al. [77], where 358-370 mg/100 g of fat were denoted. The results of the SFA, MUFA and PUFA content obtained in our work differ from the results presented by [PERSON] and [PERSON] [32], where the sum of the saturated acids in the goat's cheeses was 58.08% on average, with the advantage for unsaturated acids MUFA and PUFA (23.66 and 3.49%, respectively). In turn, higher SFA values were observed in the studies by [PERSON] et al. [78]. The high levels of SFA in milk naturally occur and dairy products are often correlated with the adverse effects of these foods and with the development of several civilization diseases, including cardiovascular disease, type 2 diabetes, obesity and cancer [79]. The differences in the chemical composition between the cited studies of the cheees may have resulted from the different production and maturation conditions of the goat's cheeses, as well as the starter culture used for their production. Due to the observed changes in the fatty acid profile and in the microstructure of the goat's cheeses during the ripening period in the present study, it is recommended to mature the goat's cheese for at least 30 days before consumption or sale. To assess the health properties of evaluated acid-rennet cheeses the Lipid Quality Indices were calculated. The Index of Atherogenicity (AI) shows the relationship between the sum of saturated fatty acids, which are considered pro-atherogenic and the sum of unsaturated fatty acids [33].