# Manufacture of a Potential Antifungal Ingredient Using Lactic Acid Bacteria from Dry-Cured Sausages
## 3 Results and Discussion
### Chemical Characterization of the Postbiotic Antifungal Ingredient
#### 3.3.1 Organic and Phenolic Acid Production
LAB can synthesize a wide variety of antifungal compounds such as organic acids, phenolic acids, antimicrobial peptides, diacetyl, and reuterin ([PERSON], 2018). During fermentation, carbon metabolism produces organic acids such as lactic acid, acetic acid, and propionic acid ([PERSON], 2018). Among these metabolites, the most studied are organic acids. It is important to mention that these metabolites can constitute synergistic activity. However, this synergistic activity's exact mechanism is unknown ([PERSON], 2018). The results also suggest that the combination of organic acids and phenolic acids produced by LAB could be responsible for the inhibitory activity of the spoilage fungi in vitro. However, it is essential to underline that the antifungal properties of the MB10 are probably not exclusively produced by organic and phenolic acids; for instance, several volatile substances can act synergistically and potentialize the antifungal properties ([PERSON] et al., 2018). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Phenolic Compound**} & \multicolumn{4}{c}{**The Concentration of Phenolic CompoundsMean \(\pm\) SD (ug/L)**} \\  & _Pediococcus pentosaceus_ C12 & _Pediococcus pentosaceus_ C15 & _Lacitplantibacillus plantarum_ C60 \\ \cline{2-5}  & **MRSb** & **MB10** & **MRSb** & **MB10** & **MRSb** & **MB10** \\ \hline
1,2–Dibhydroxybenzene & 9.39 \(\pm\) 2.02 a & 2.51 \(\pm\) 0.41 b & 5.86 \(\pm\) 2.74 c & 5.64 \(\pm\) 2.22 c & 7.12 \(\pm\) 1.3 d & 4.64 \(\pm\) 1.39 c \\ Propionic acid & 7.14 \(\pm\) 1.79 a & 7.08 \(\pm\) 1.34 a & 9.66 \(\pm\) 2.64 a & 9.36 \(\pm\) 0.62 a & 6.19 \(\pm\) 2.85 a & 13.44 \(\pm\) 5.58 b \\ Benzoic acid & 31.65 \(\pm\) 4.42 a & 18.09 \(\pm\) 5.35 b & 24.69 \(\pm\) 0.72 c & 22.12 \(\pm\) 7.32 b & 19.38 \(\pm\) 5.91 b & 23.18 \(\pm\) 0.35 b \\ Caffe acid & 4.07 \(\pm\) 1.46 a & 3.99 \(\pm\) 2.46 a & 8.37 \(\pm\) 1.26 b & 7.72 \(\pm\) 1.87 b & 3.40 \(\pm\) 0.97 a & 6.27 \(\pm\) 1.55 c \\ DL–3–Theymalactic acid & 18.17 \(\pm\) 3.52 a & 18.30 \(\pm\) 1.54 a & 31.90 \(\pm\) 7.49 c & 22.68 \(\pm\) 3.25 b & 16.98 \(\pm\) 3.66 a & 15.85 \(\pm\) 0.61 a \\ Ferulic acid & n.d & n.d & 4.79 \(\pm\) 1.81 a & 5.85 \(\pm\) 0.20 a & 3.70 \(\pm\) 0.72 a & 6.18 \(\pm\) 1.26 b \\ Gallic acid & n.d & n.d & 4.20 \(\pm\) 2.83 a & 6.06 \(\pm\) 1.88 a & 6.58 \(\pm\) 2.05 a & 7.44 \(\pm\) 1.25 a \\ p–Coumaric acid & 22.59 \(\pm\) 9.91 a & 9.37 \(\pm\) 1.72 b & 6.28 \(\pm\) 0.07 b & 7.56 \(\pm\) 0.44 b & 5.29 \(\pm\) 1.47 b & 4.99 \(\pm\) 2.03 b \\ Singicylic acid & 4.87 \(\pm\) 1.04 a & 6.43 \(\pm\) 0.44 c & 5.85 \(\pm\) 2.38 a & 7.86 \(\pm\) 3.66 c & 3.54 \(\pm\) 0.86 b & 7.22 \(\pm\) 1.32 c \\ Synergistic acid & 26.78 \(\pm\) 3.52 a & 19.47 \(\pm\) 5.28 b & 17.73 \(\pm\) 4.12 b & 21.12 \(\pm\) 0.39 b & 17.42 \(\pm\) 1.40 b & 12.83 \(\pm\) 3.40 c \\ Vanillic acid & 20.84 \(\pm\) 4.56 a & 18.81 \(\pm\) 2.82 a & 10.83 \(\pm\) 6.19 b & 25.18 \(\pm\) 1.13 a & 27.60 \(\pm\) 2.94 b & 24.00 \(\pm\) 2.12 c \\ Vanillin & 11.68 \(\pm\) 1.26 a & 13.76 \(\pm\) 1.08 a & 16.85 \(\pm\) 5.47 a & 13.73 \(\pm\) 1.72 a & 7.57 \(\pm\) 1.65 b & 8.46 \(\pm\) 1.51 b \\ \hline \hline \end{tabular}  
* Different letters mean a significant statistical difference in the concentration of phenolic compounds among fermented broth (\(p\leq 0.05\)). n.d means not detected.  
\end{table} 
Table 5: The concentration of phenolic compounds in Man, Rogosa and Sharpe broth (MRSb) and meat broth (MB10) fermented by antifungal LAB. The broth were fermented for 48 h at 37 \({}^{\circ}\)C.  
Moreover, the decrease in pH collaborates to a more efficient antifungal activity [47]. In this context, [PERSON] et al. [48] found that organic acids and phenolic acids generated by some LAB strains as antifungal metabolites have synergistic actions against _F. culmorum_. Likewise, in bakery products, organic acids and antifungal peptides produced by LAB showed a significant synergistic effect which allowed biopreservation and enhanced the shelf life of quinoa and rice bread [49].