The Use of the Mixed Bacteria _Limosilactobacillus fermentution_ and _Staphylococcus carnosus_ in the Meat Curing Process with a Reduced Amount of Sodium Nitrite  
[PERSON]  
1 Department of Meat and Fat Technology, Prof. [PERSON] Institute of Agricultural and Food Biotechnology, 36 Raviowieck St., 0-2532 Warsaw, Poland, [EMAIL_ADDRESS] (B.L.); [EMAIL_ADDRESS] (A.K.-J.);[EMAIL_ADDRESS] (C.R.); [EMAIL_ADDRESS] (A.K.  
result of metmyoglobin reduction (MetMb) with ascorbic acid [6]. The nitrites dismutution process is also observed during the heat treating of meat products. It was shown that the heat-treating temperature influences the oxidation dynamics of nitrites to nitrates [5]. In the studies on nitrite added to the meat balance, it was observed that 1 to 10% of added nitrites oxidises to nitrates [7; 8]. Other authors estimate that the amount of nitrites being transformed into nitrates during curing may be higher and may reach even 40% [4].  
Recently, there has been an increase in consumer demand for foods with fewer chemical additives that are perceived to be healthier. Therefore, meat products without or reduced added nitrite/nitrate are characterized by high consumer acceptance. For that reason, in the industry, there are increased demands to reduced nitrite and nitrate in the processing of meat products [9; 10]. There is now an EU law regulation aiming to reduce the use of nitrites in producing meat products [11]. In addition, some countries e.g., Denmark, previously implemented internal regulations, reducing the maximum level of nitrites permitted in the European Union from 150 to 60 mg/kg in chosen processed meat groups [12].  
Selected coagulase-negative nonpathogenic species of the _Staphylococcus_ genus and lactic acid bacteria strains (LAB) used as starter cultures in fermented processed meat production are responsible for the colour, taste and flavour of these products [13]. In the process of anaerobic respiration _Staphylococcus_ bacteria use nitrates as the final electron acceptors. The electrons detached from the respiration substrate are bonded by the nitrate reductase enzyme to nitrates and form nitrites [14]. Proper use of selected strains of the _Staphylococcus carnosus_ bacteria in the meat curing process may be useful in reducing the amount of sodium nitrite added into heat treated meat products by reducing nitrates formed from oxidized nitrite [15]. On the other hand, using only _Staphylococcus carnosus_ bacteria in nitrite meat curing may not bring about the intended effects. In the case of the insufficient reduction potential of the meat environment NO\({}_{2}\) formed as a result of NO\({}_{3}\) bacterial reduction will not be chemically reduced to NO [5]. After depleting NO\({}_{3}\) by bacteria, NO\({}_{2}\) cumulated in the environment will be absorbed by cells, reduced to ammonia (NH\({}_{3}\)) and excreted into the environment [16; 17]. Cumulated NH\({}_{3}\) may have a destructive effect on MbFe\({}^{\text{II}}\)NO and meat colour. The lactic acid bacteria may be useful in optimizing the process of meat curing with a reduced amount of sodium nitrite for producing cooked meat products. Some LAB strains are able to reduce NO\({}_{2}\) to NO by producing acid and nitrate reductase activity depending on heme or independence from heme [18]. Studies on the biochemical attributes of LAB isolated from ecological acidic whey indicate that selected bacteria strains _Limosilactobacillus fermentatum_ could be useful in optimizing the meat curing process [19].  
The goal of this research was to estimate the possibility of using a mixed culture consisting of _Limosilactobacillus fermentatum_ S8 and _Staphylococcus carnosus_ ATCC 51365 in meat curing with a reduced amount of sodium nitrite and to estimate the effect of bacteria on nitrites and nitrates residues, nitrosyl pigments content, colour, pH, redox potential, microbiological and the sensory quality of the model cooked meat product.