## 3 Results
### Characterization of Natural Extracts
#### 3.1.4 Antimicrobial Activity  
Figure 1 shows the antimicrobial capacity against _Clostridium perfringens_ growth in the presence of all studied extracts, species, and vegetables. In these graphics, it can be appreciated that all extracts reported antimicrobial activity by inhibiting growth or causing bacterial death of _Clostridium perfringens_.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & \multicolumn{2}{c}{**Chelating Activity Percent (\%)**} & \multicolumn{2}{c}{**Antioxidant Activity (\(\upmu\)M TE g\({}^{-1}\)\(\upmu\) SD)**} \\ \cline{2-6}  & **ABTS** & **DPPH** & **ORAC** & **FRAP** & **ORAC**[23] \\ \hline Ct & 15.4 \(\pm\) 0.2 h  & 8.45 \(\pm\) 0.3 k  & 4828.5 \(\pm\) 19.9 d  & 6004.7 \(\pm\) 29.6 c  & Nd \\ Ac & 46.5 \(\pm\) 0.3 c  & 78.3 \(\pm\) 0.5 k  & 16.80 \(\pm\) 0.2 c  & 5746.0 \(\pm\) 21.7 c  & 2491.3 \(\pm\) 17.1 c  & 13.750 \\ Garlic & 25.4 \(\pm\) 0.8 e  & 51.5 \(\pm\) 0.3 d  & 1919.3 \(\pm\) 23.4 s  & 450 \\ Oregon & 15.6 \(\pm\) 0.5 h  & 11,43.6 \(\pm\) 21.7 c  & 2491.8 \(\pm\) 30.2 c  & 6004.7 \(\pm\) 29.6 c [FOOTNOTE:k]Footnote : Ct. Citric; R: Rosemary; Acerola; L: Lettuce; A: Arrugula; S:Taking into account that the control sample represents the total bacterial growth (100% bacteria), it can be observed that B only reduced 65% of bacterial growth, while acerola and C decreased by 85% using 1000 ppm of each extract. Moreover, the rest of the ingredients reduced the bacterial growth between 90% and 100% compared to the control. Similarly, it can be said that the concentration of each ingredient applied directly influences their antimicrobial capacity, at least from 250 to 1000 ppm, because it may be possible that a higher concentration causes a loss of this effect due to saturation of the system.  
On the other hand, the extracts that reported the highest antimicrobial activity (\(p<0.05\)) were R (100% at 1000 ppm), followed by garlic, paprika, oregano, and the rest of leafy green vegetables rich in nitrates (Ce, L, S, Ch, A, and W, from 98% to 90%, in this order, at 1000 ppm). Consequently, it can be affirmed that the antimicrobial power of the extracts studied against _Clostridium perfringens_ growth is related to the total phenolic and nitrate content. Actually, the bacterial growth (CFU) of _Clostridium perfrigens_ has been directly related (\(p<0.05\)) to the concentration of nitrates, which was already described by [PERSON] and [PERSON] [27].  
In addition, phenolic compounds from R (_Rosmarinus officinalis_) and allicin from garlic have been described as antimicrobial agents acting in different ways: Affecting the cytoplasmic membrane structure, blocking protein synthesis and affecting any of the phases of this process (activation, initiation, binding of the tRNA amino acid complex to ribosomes, or elongation), affecting the metabolism of nucleic acids, and/or blocking any bacterial metabolic pathways.  
Figure 1: Antimicrobial activity of natural extracts expressed by bacterial growth (cfu) at different concentrations in _Clostridium perfringens_ NCTC 8237 CECT 376 after 48 h incubation at 37 \({}^{\circ}\)C under anaerobic conditions. (**A**) obtained results for Ct: Citric; R: Rosemary; Ac: Acerola; (**B**) obtained results for Paprika, Garlic, and Oregano; (**C**) obtained results for L: Lettuce; A: Arugula; S: Spinach; Ch: Chard; Ce: Celery; W: Watercross. Superscript letters indicate significant differences (\(p<0.05\)) between samples. Control sample represents the normal bacterial growth without any extract.