1) The study examined the effect of pre-wash chopping and storage conditions of parsley on the efficacy of sanitizing washes against Salmonella Typhimurium contamination. 2) Parsley samples that were chopped and stored at warm temperatures (30C for 4 hours) had significantly lower log reductions of Salmonella after washing compared to intact or cold stored samples. 3) Sodium dichloroisocyanurate (NaDCC) achieved the highest log reductions of 1.92-3.12 and is an effective and economic sanitizer for fresh produce compared to water, vinegar, and chlorine treatments. 4) Proper temperature control during the handling of parsley before washing is important to

1. The influence of pre-wash chopping &
storage conditions of parsley on the efficacy
of disinfection against S. Typhimurium
Dima Faour-Klingbeila, Victor Kuria, Ewen C.D. Toddb
aSchool of Biological Sciences, Plymouth University, UK
bEwen Todd Consulting, Okemos, MI, USA & Department of Nutrition and Food Science,
American University of Beirut, Lebanon
Application of scenarios based on handling practices during
preparation of traditional parsley salads “Tabbouleh” in
Beirut, Lebanon and other MENA countries

2. Fresh Produce:
A global concern
• Fresh produce-related outbreaks continue to occu
worldwide
• Norovirus, Escherichia coli O157:H7,
Campylobacter, Listeria monocytogenes, and
Salmonella being frequently encountered in
outbreaks

4. Recent fresh produce-related outbreaks
Type of
produce/Origin
Note
2015: Salmonella Poona outbreak ,767
people infected from 36 states
Cucumbers from
Mexico
Unknown
2014: Salmonella Newport outbreak
sickened 257 patients in 29 states and the
District of Columbia.
Source. CSPI ,2015
Cucumbers /
unidentified source
The bacteria was assumed
to be linked to the
application of manure.
2012: Salmonella Typhimurium and
Salmonella Newport in 2012, sickened 261
people in 24 states, 3 deaths and 94
hospitalizations.
Source. CSPI 2015
Cantaloupes An inspection found
unsanitary conditions in
the farm’s processing shed.
2008: Salmonella Saintpaul sickened 1,442
people in 43 states.
Source. CSPI 2015
Jalapeño and serrano
peppers and pepper
products (e.g., salsa)/
Mexico
Suspected caused
contaminated irrigation
water

5. CHALLENGES
IN LEBANON

6. Litani River pollutants force
residents from homes
6
The practice is now threatening
to become an environmental
disaster harming the country’s
agricultural sector.

7. Shortfalls in GAP
• Dip washing parsley &
radish
• Sewage directed into
pools/streams
Faour-Klingbeil D., Murtada M., Kuri V., and Todd E., 2016.

9. Parsley in the Mediterranean cuisine
Use of sanitizing agents in small and medium sized foodservice is
limited (Faour-Klingbeil D., Murtada M., Kuri V., and Todd E., 2015)

10. OBJECTIVES
Examine the decontamination effect of the washing
methods applied in SMEs in typical scenarios of
parsley preparation:
Pre-wash chopped parsley held under different
time-temperature conditions

11. METHOD
1 Ltr inoculum
suspensions with
targeted CFU/ml of
S.Typhimuriuml
120g
Washed
Scenario 2
Scenario 1

12. -Water wash
-Vinegar
- Sodium
dichloroisocyanurate
-Chlorine
5ºC for 4 h
5ºC for 24 h
30ºC for 4 h
Scenario 1-Intact Scenario 2 - Chopped
20g soaked in
200 ml washing
solutions
(ca.22ºC)
For 15 min

13. • 1000 ppm chlorine (Chlor-Clean®, pH 5.94)
• 0.25 g/l Sodium dichloroisocyanurate (NaDCC)
(Presept®, pH 6.14)
• White vinegar (4%, v/v, acetic acid)
• Deionized water (Milli-Q plus) : rinsing twice, with
manual agitation (2-3 s in 3 successions)
All experiments were replicated at least 3 times and
carried out in duplicate.

14. Scanning Electron Microscopy

15. STATISTICALANALYSIS
• Two-way ANOVA - Interaction effect
• Independent t-test
• The reduction of microbial content:
log-cycles, i.e. log (N/N0)

16. Pre-wash storage conditions
(Temperature/Time)
Washing 5ºC/4 h 5ºC/24 h 30ºC/ 4 h
Chopped
Solutions pHª Mean±SD Mean±SD Mean±SD
Control1 6.38 ± 0.54 5.91 ± 0.10 7.14 ± 0.44
Water 6.30 5.44 ± 0.36 5.64 ± 0.27 6.55 ± 0.48
Vinegar 3.65 6.02 ± 0.55 5.32 ± 0.47 6.60 ± 0.25
NaDCC 6.09 3.99* ± 0.79 3.62* ± 0.12 5.21* ± 0.19
Chlorine 6.11 2.51* ± 0.28 2.64* ± 0.45 4.19* ± 0.11
Un-chopped Control1 6.20 ± 0.53 5.84 ± 0.09 6.98 ± 0.45
Water 6.45 4.69* ± 0.38 4.74* ± 0.13 6.16* ± 0.22
Vinegar 3.49 5.12* ± 0.51 4.66* ± 0.12 6.11 ± 0.61
NaDCC 6.10 3.08* ± 0.45 3.18* ± 0.27 5.09* ± 0.20
Chlorine 6.00 1.28†*± 0.80 2.55* ± 0.63 4.26* ± 0.21
RESULTS 1/5

17. RESULTS 2/5
Chopped vs Unchopped
*
*
*
*

18. RESULTS 3/5

19. RESULTS 4/5
Pre-wash storage conditions
(Temperature/Time)
Chopped Unchopped
Washing
solutions
5ºC/4h 5ºC/24 h 30ºC/4 h 5ºC/4 h 5ºC/24 h 30ºC/4 h
Water -0.93a -0.27 -0.59a -1.51a -1.098b -0.84ab
Vinegar -0.36 -0.59a -0.54a -1.08a -1.18b -0.90ab
NaDCC -2.39a -2.19b -1.93ab -3.12a -2.65b -1.92ab
Chlorine* -3.87a -3.11b -2.96ab -4.92a‡ -3.29b -2.74ab

20. Unchopped
5ºC/24 h
Chopped
5ºC/ 24 h
Washing solutions Log (N/N0) Log (N/N0)
Water -0.98 -0.48
Vinegar -1.25 -1.14
NaDCC -1.85 -1.71
Chlorine -2.27 -2.62
RESULTS 5/5

21. SEM micrograph
S.Typhimurium
agglomerated at
the inner sides
of small veins
and crevices of
the parsley leaf .

22. SEM micrograph
The initiation of the formation of extracellular polysaccharide matrix in the netting
of the inoculated parsley leaf

23. CONCLUSION
• Chopping parsley and holding at warm temperature
would substantially limit effectiveness of washing
procedures to 0.5-1.9 log
• NaDCC an acceptable economic alternative for fresh
produce sanitation permitting a log reduction range of
1.92-3.12

24. CONCLUSION
Adequate temperature control over time during
handling of parsley

25. QUESTIONS AND FEEDBACK ?

26. SEM MICROGRAPH
NaDCC for 15 minutes vinegar (4%, v/v, acetic
acid)