# Postharvest Reduction of _Salmonella enterica_ on Tomatoes Using a Flagmonic Acid Emulsion
## 3 Results  
### Reduction of Salmonella on Inoculated Tomatoes Over Time  
Overall, _Salmonella_ counts on tomatoes treated with PEL decreased to a greater extent than _Salmonella_ on tomatoes treated with chlorine, PAA, water or NR. The PEL emulsions also controlled cross-contamination onto SUS significantly better than chlorine and PAA. Overall, sanitizer type and storage time significantly interacted with _Salmonella_ populations (Table 2) but organic load had no significant impact on sanitizer efficacy at any time point. At 0 d, both PEL emulsions resulted in significant reductions (ca. 1 log CFU/g) over chlorine and PAA (Table 2). Chlorine (7.03 log CFU/g) and PAA (6.73 log CFU/g) performed statistically similarly to the water (7.35 log CFU/g) and NR (7.53 log CFU/g) controls, while both PEL emulsions resulted in significantly greater reductions than chlorine, PAA, water and NR (\(p\leq 0.05\)). After 1 d storage, all four sanitizers resulted in significantly greater _Salmonella_ reductions than the water and NR controls. Chlorine caused a significantly lower reduction than all other sanitizers at 1 d, with 5.38 log CFU/g _Salmonella_ recovered. PAA (3.23 log CFU/g) performed significantly better than chlorine at 1 d but was less effective than both PEL sanitizers, from which 1.86 log CFU/g (30 mM PEL) and 1.16 log CFU/g (50 mM PEL) _Salmonella_ were recovered. By comparison, _Salmonella_ was recovered at 7.59 and 7.96 log CFU/g from water and NR, respectively, after 1 d storage. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Storage Time (d)**} \\ \cline{2-6}  & **0** & **1** & **7** \\ \cline{2-6}  & \multicolumn{6}{c}{**Log CFU/g**} \\ \hline  & \multicolumn{6}{c}{Sanitizer} \\ \hline Chlorine & 7.03 \(\pm\) 0.06 & a\({}^{1}\)A\({}^{2}\) & 5.38 \(\pm\) 0.30 & aB & 5.28 \(\pm\) 0.26 & aB \\ PAA & 6.73 \(\pm\) 0.10 & aA & 3.23 \(\pm\) 0.51 & bB & 2.92 \(\pm\) 0.50 & bB \\
30 mM PEL & 5.76 \(\pm\) 0.08 & bA & 1.86 \(\pm\) 0.21 & cB & 1.00 \(\pm\) 0.00 & cC \\
50 mM PEL & 5.37 \(\pm\) 0.17 & bA & 1.16 \(\pm\) 0.08 & cB & 1.15 \(\pm\) 0.10 & cB \\ \hline \multicolumn{6}{c}{No treatment} \\ \hline Water & 7.35 \(\pm\) 0.05 & 7.59 \(\pm\) 0.06 & 7.57 \(\pm\) 0.11 \\ NR & 7.53 \(\pm\) 0.11 & 7.96 \(\pm\) 0.14 & 7.73 \(\pm\) 0.22 \\ \hline \multicolumn{6}{c}{Contrasts} \\ \hline Sanitizer vs. Water & & & & & \\ Chlorine \(\times\) Water & ns & ** & & ** \\ PAA \(\times\) Water & ns & & & ** \\
30 mM PEL \(\times\) Water & ** & & & ** \\
50 mM PEL \(\times\) Water & ** & & & ** \\ \hline \multicolumn{6}{c}{Sanitizer vs. NR} \\ \hline Chlorine \(\times\) NR & ns & & ** & & ** \\ PAA \(\times\) NR & ns & & & ** \\
30 mM PEL \(\times\) NR & ** & & & ** \\
50 mM PEL \(\times\) NR & ** & & & ** \\ \hline \multicolumn{6}{c}{No treatment} \\ \hline Water \(\times\) NR & ns & ns & ns & \\ \hline \hline \end{tabular} \({}^{1}\) Values followed by similar lowercase letter indicate no significant differences (\(p\geq 0.05\)) among sanitizer 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 sanitizer treatments (rows). ns, **, *** & nonsignificant or significant at \(p\leq 0.01\), 0.001, respectively. PAA, peroxyacetic acid; OL, organic load; PEL, pelargonic acid; NR, no rinse.  
\end{table} 
Table 2: Log populations (CFU/g) of _Salmonella enterica_ on the inoculated tomato surface immediately after sanitizer treatment (0 d) and throughout 1 d and 7 d storage at 8 \({}^{\circ}\)C. There were no significant third and second order interactions among organic load (OL), sanitizer and storage duration treatments, so OL and non-OL sanitizer data were analyzed and reported together (sanitizer \(n=16\); no treatment \(n=8\)).