# Postharvest Reduction of _Salmonella enterica_ on Tomatoes Using a Flagmonic Acid Emulsion
## 4 Discussion
coli_ O157:H7 was not significantly affected up to 10% organic load in the form of blended iceberg lettuce [50]. Finally, neither PEL treatment was affected by organic loading, which was anticipated as organic acids are highly stable in the presence of organic material [12]. These studies indicate that the 0.5% organic load supplemented in the current study was likely insufficient to quench the antimicrobial activity of any of the examined sanitizers, including chlorine; a higher level (>0.5%) of organic loading may have elicited a significant reduction in efficacy. The brix of the tomato puree was not measured in the current study but this information could have provided insight into the effectiveness of the organic loading methodology. Tomato extract or sterilized soil, instead of tomato puree, may have been more suitable proxies for simulated organic loading in a produce wash system. Firmness and skin strength of the grape tomatoes treated with water, chlorine and PAA, as well as NR, remained relatively stable (no significant changes) during storage. [PERSON] et al. [51] also found that the firmness of grape tomatoes after rinsing with water remained constant throughout 21 d storage at 10 \({}^{\circ}\)C. Chlorine is known to have minimal negative effects on produce quality parameters such as texture [35]. [PERSON] et al. [52] conducted triangle sensory tests comparing the effects of water and various sanitizers on fresh-cut carrots (\(n=18\)). There was a significant difference between carrots treated with water and 200 ppm chlorine; deviant taste and odor were noted by panelists. In the same study, there was not a significant difference between carrots treated with water versus those treated with 80 ppm PAA. However, there was a significant difference between carrots treated with water versus carrots treated with 250 ppm PAA; deviant taste and texture were noted. A disadvantage of PEL as a produce wash can likely be attributed to its activity against cell membranes of plant and microbial cells alike. Pelargonic acid desiccates plant tissues by disrupting the cell membrane and removing the waxy cuticle, which results in cell leakage and rapid cell death similar to that seen in prokaryotic cells, leading to tissue discoloration and loss of structural integrity [24]. Exposure to 50 mM fumaric acid for 10 min reduced _S. enterica_ ser. Typhimurium, _Staphylococcus aureus and E. coli_ O157:H7 populations on lettuce by over one log; however, tissue browning occurred [53]. In this study, grape tomatoes exposed to PEL did not exhibit noticeable color change but significant textural changes occurred after 1 d of storage. Both firmness and skin strength decreased significantly from 0 d to 1 d for tomatoes that were treated with PEL. Decreased firmness and skin strength in tomatoes treated with PEL were expected, as PEL can penetrate the waxy cuticle and disrupt membrane permeability. These actions lead to cell leakage and desiccation, similar to the effect seen on PEL-exposed bacteria [22; 24; 54]. Due to chemical and structural differences, it is possible that other tomato cultivars or stages of maturity may be more tolerant to the phytotoxic activity of PEL [55; 56; 57]. Incorporation into polysaccharide films, such as pullulan and chitosan, has shown promise for other antimicrobials used on fresh produce and may be a useful delivery mechanism for PEL-based sanitizers [58]. Aside from the impact of PEL on texture, another consideration is that PEL has a fatty, coconut aroma, which in some cases has been described as rancid [59; 60]. In this study, a coconut aroma was noticeable and persisted from the time of treatment through 7 d of tomato storage, which is undesirable for fresh produce.