# Postharvest Reduction of _Salmonella enterica_ on Tomatoes Using a Flagmonic Acid Emulsion
## 4 Discussion  
Overall, the PEL sanitizer treatments significantly reduced _Salmonella_ recovery from tomatoes, both immediately post-treatment and after storage. _Salmonella_ was recovered at a rate of 5.76 log CFU/g (PEL 30) and 5.37 log CFU/g (PEL 50) immediately post-treatment, an improvement of 1.77 and 2.16 log CFU/g over simulated field packed (NR control) tomatoes. The least effective sanitizers examined, chlorine (7.03 log CFU/g) and PAA (6.73 log CFU/g), resulted in statistically similar reductions of _Salmonella_ at 0 d. These reductions were also statistically similar to those observed by the water (7.35 log CFU/g) and NR (7.53 log CFU/g) controls. In a 2019 study, [PERSON] et al. found similar reductions on _Salmonella_-inoculated pepppers; 200 ppm chlorine resulted in a statistically significant but less than 1 log CFU/g reduction when compared to a NR rinse control and performed statistically the same as the water control [14]. Interestingly, [PERSON] et al. found that a 200-ppm wash used on _Salmonella_ inoculated grape tomatoes resulted in a greater than 4 log CFU/g reduction. However, the tomatoes in the [PERSON] and [PERSON] study were rinsed under continuous agitation for 5 or 10 min [35], which may be more comparable to conditions and exposure time in a hydrocooler [36]. The current study's 2 min treatment in a static bath was intended to mimic typical exposure time in a packinghouse dump tank. The most significant differences in antimicrobial efficacy among treatments occurred during storage. Throughout storage (0 d to 7 d), _Salmonella_ populations on inoculated NR and water-washed control tomatoes water underwent no significant changes and were statistically similar to each other. This is consistent with the findings of [PERSON] et al. [37], which found that populations of _S. enterica_ Montevideo inoculated onto the surface of mature green tomatoes remained relatively constant when stored at 10 \({}^{\circ}\)C for 18 d. Survival during this extended period indicates that _Salmonella_ can survive throughout tomato transport in the absence of mitigation strategies (e.g., sanitizing washes) and could remain viable when it eventually reaches the consumer. Conversely, both PEL treatments resulted in significant decreases (>3.8 log CFU/g) in _Salmonella_ from 0 d to 1 d, after which populations persisted at very low levels, close to or below the limit of detection of 1 log CFU/g through 7 d storage. The antibacterial efficacy of chlorine was most evident from 0 d to 1 d, when it resulted in a statistically significant, nearly 2 log CFU/g reduction (7.03 log CFU/g to 5.38 log CFU/g); however, no significant, continued biocidal activity occurred from 1 d to 7 d (5.29 log CFU/g). The PAA treated tomatoes over time performed significantly better \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Storage Time (d)**} \\ \cline{2-7}
**Treatments** & \multicolumn{2}{c}{**0**} & \multicolumn{2}{c}{**1**} & \multicolumn{2}{c}{**7**} \\ \cline{2-7}  & \multicolumn{6}{c}{**Force (N)**} \\ \hline Chlorine & 15.47 \(\pm\) 0.84 & a 1A 2  & 16.24 \(\pm\) 1.30 & aA & 18.80 \(\pm\) 0.78 & aA \\ PAA & 16.87 \(\pm\) 1.30 & aB & 15.29 \(\pm\) 0.72 & aB & 19.46 \(\pm\) 1.58 & aA \\
30 mM PEL & 17.27 \(\pm\) 1.06 & aA & 7.01 \(\pm\) 0.29 & bB & 8.60 \(\pm\) 0.49 & bB \\
50 mM PEL & 15.30 \(\pm\) 1.69 & aA & 7.17 \(\pm\) 0.54 & bB & 6.14 \(\pm\) 0.33 & bB \\ Water & 16.17 \(\pm\) 0.63 & aB & 16.45 \(\pm\) 1.16 & aB & 20.54 \(\pm\) 1.50 & aA \\ NR & 15.82 \(\pm\) 1.09 & aB & 16.47 \(\pm\) 0.63 & aB & 19.99 \(\pm\) 1.09 & aA \\ \hline \hline \end{tabular}  
* Values followed by similar lowercase letter indicate no significant differences (\(p\geq 0.05\)) among treatments (rows) within storage time (columns). 2 Values followed by similar uppercase letter indicate no significant differences (\(p\geq 0.05\)) among storage time (columns) within treatments (rows). PAA, peroxyacetic acid; PEL, pelargonic acid; NR, no rinse.  
\end{table}