# Functional and Clean Label Dry Fermented Meat Products:
## 3 Bioactive Compounds from Plant-Based Food as \"Clean Label\" Ingredients in Fermented Sausages
This pathogen is highly difficult to control in fermented sausage processing environments because of its high tolerance to a high salt content and low pH. The optimum growth conditions of _L. monocytogenes_ include a temperature in the range of 30-37 \({}^{\circ}\)C, optimum pH between 6 and 8 (however, it can grow at pH ranges from 4.5 to 9.0), NaCl levels of 12%, and water activity values of 0.92 [78; 79]. However, nitrites and nitrates have inhibitory effect on _L. monocytogenes_ growth in dry-fermented sausage [80]. The research conducted by [PERSON] et al. [81] showed that a lower content of nitrite and nitrate would increase _Listeria_ counts in case of contamination with this microorganism. Therefore, the elimination of nitrates requires alternative and efficient measures to inhibit the growth of this pathogen. In this sense, [PERSON] et al. [82] investigated the inactivation of _L. monocytogenes_ during the manufacturing process of Milano-type salami elaborated without nitrites/nitrates and with vegetable additives (carrot and Swiss chard juice concentrate powder) to assess the pathogens' behavior when exposed to alternative additives or nitrite/nitrate replacements from vegetable origin. The results showed no growth of _L. monocytogenes_ during the process, even in case when the salami was elaborated without nitrites/nitrates. The authors point to the key role of other barriers to inhibit the growth of pathogens in the elaboration of raw fermented meat products, such as pH and water activity. A related experiment indicated that the same protective effect of leaf celery and spinach extract encapsulated in tubular cellulose improved the preservation of redness and also reduced the load of microorganisms (_enterobacteriaceae_, lactic acid bacteria, yeasts, and molds) [83]. The scientific research for ingredients of plant origin with antimicrobial properties for incorporation into raw fermented meat products notably increased in recent years. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Function** & **Mechanisms** & **References** \\ \hline The formation and stabilization of red color & \begin{tabular}{c} _Benefits_ \\ Nitric oxide reaction with myoglobin \\ (deoxymyoglobin and metmyoglobin) forms \\ nitrosymyoglobin complex, which generates the unique cured-meat color \\ \end{tabular} & [59] \\ Preservative effect & \begin{tabular}{c} Antimicrobial effect due to the reduction in oxygen \\ uptake, inactivation of some metabolic enzymes, \\ and breakage of the electron transport chain \\ Inhibition of growth of some anaerobic bacteria, \\ including _Clostidium botulinum_ and its toxins, \\ _Clostidium perfringers, Staphylococcus cereus_, _Bacillus cereus_, and _Listeria monocytogenes_ \\ Improvement of the oxidative stability & \begin{tabular}{c} Nitrite and nitrate delay the lipid oxidation through \\ oxygen deletion \\ Nitric oxide can react with radicals (alkoxy radicals, \\ hydroxyl radical, and peroxyl radicals) interrupting \\ radical chain reactions and bind to transitional \\ \end{tabular} & [61; 62] \\ Contribution to the flavor formation & \
\begin{tabular}{c} Several compounds are formed when nitrite is \\ bound to proteins and lipids. For example, when \\ nitrites are bound to sulfur-containing amino acids \\ of meat proteins, SH-residues with a specific flavor \\ and aroma are formed and contribute to the flavor \\ of cured meat \\ Potential formation of N-nitrosamines &
\begin{tabular}{c} _Risk_ \\ The addition of nitrates and nitrites to the processed \\ meat can induce the development of N-nitroso \\ compounds linked with metabolic and genotoxicity \\ disturbances in the large intestine mucosa \\ \end{tabular} & [64; 74; 75; 65] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The role of nitrates/nitrites in meat products. Several natural extracts and ingredients (based on herbs and spices, vegetables, or fruits) were applied to fermented meat products as clean label alternatives to nitrites [55; 84; 85]. [PERSON] et al.