# Quantitative Microbiological Analysis of Artisanal Stretched Cheese Manufacture
## 4 Discussion  
Cheese production belongs to the largest sectors of the dairy and food industries, and much of it is still realized in an artisanal environment using raw milk [28]. While long-ripened cheeses produced under hygienic conditions are not the frequent subject of microbiological quality or safety concerns, the fresh, soft, or short-ripened raw milk cheeses are the subjects of potential health risk discussions. Despite the history and considerable expansion of the artisanal production of steamed and stretched cheees in Slovakia, there is a lack of data not only on the volumes produced but also on the consumption of this kind of raw milk cheeses, as the relevant consumption is hidden within the group of soft cheeses at approximately 2 kg/person/year [29]. Towards preliminary exposure assessment, microbiological data during their production and storage are needed. That is why this study deals with the quantitative changes of microbial indicators in the relevant steps of the manual production of raw milk steamed and stretched cheese, thus contributing to discussions about the quality and safety of traditional Slovakian cheeses. It is well known that the first production steps, including curd fermentation, are the most critical for potential microbial growth of undesirable microorganisms, here represented via indicators as well as the counts of _E. coli_ and _S. aureus_[9; 13; 30; 31]. Importantly, the proliferation of spoilage or pathogenic microorganisms at these early steps should be effectively limited by a starter culture of lactic acid bacteria (SLAB). Their inhibitory effects are linked to the rate of lactose fermentation or lactic acid production, the associated decrease in pH, and finally their growth competitive abilities [32; 33]. Additionally, SLAB can produce other antimicrobial metabolites, such as bacteriocins and non-protein organic compounds [34; 35]. To ensure consistency of the fermentation process, the SLAB need to be active and dominant in the curd. That is why the mesophilic culture Fresco DVS 1010 was used in this work. In this way, LAB counts close to 9 log CFU/g were reached within the first 24 h. Based on data from competitive growth modelling among three populations (LAB, _S. aureus_, and _E. coli_), an initial number of LAB at 5 log CFU/mL was able to bring the populations of _S. aureus_ and _E. coli_ under control, reaching numbers higher than 8 log CFU/g at 30 \({}^{\circ}\)C after 6 h, while at initial 6 log CFU/mL of LAB, 8 log CFU/g was reached after 4 h [36]. [PERSON] et al. [34] pointed also to the ratio between _S. aureus_ and SLAB as a determining parameter for the efficacy of _S. aureus_ inhibition in the cheese matrix [33]. Thus, prior to steaming and stretching, the counts of _E. coli_ and _S. aureus_ in 24 h curd remain between \(10^{3}\) and \(10^{4}\) CFU/g. However, the question remains in this study of the extent to which the manually performed steaming and stretching process inactivates the populations in the curd. It seems that the results in shown in Figure 6 and the subsequent microbiological storage data at 6 \({}^{\circ}\)C (Figure 7) confirm that the inactivation step sufficiently reduces the microbial population and keeps CFM, _E. coli_, and _S. aureus_ under control. On the other hand, according to [PERSON] et al. [15] and [PERSON] et al. [16], the coliforms can be reduced by up to 4 log CFU/g in heat-treated curd. On the contrary, but in accordance with [PERSON] et al. [37], an _S. aureus_ population was present in all prepared fresh pasta filata cheeses, probably due to their tolerance to mild heat treatment [36] or to secondary contamination, as this is not possible to exclude during manual preparation. For example, [PERSON] et al. [16] reported 99.7% mean inactivation of total staphylococci after stretching the curd at \(\sim\)80 \({}^{\circ}\)C during Kashakval \"pasta filata\" cheese production [16]. [PERSON] et al. [38] showed a significant decrease (\(p<0.05\)) in coliform bacteria, including _E.