- Salmonella was in 1.23% of the samples (average level of 0.110 MPN/g),
- EHECs occurred in 0.44% of the samples (0.039 MPN/g),
- Listeria spp. occurred in 0.08% of samples (0.020 MPN/g), but L. monocytogenes was not detected.
A few important discussion points:
- "Contamination sources are diverse and vary with several conditions, including weather, temperature, precipitation, time of flowering, and time of harvest." So there is no silver bullet in eliminating this contamination from getting on the raw product.
- "There are two main pathways in which the presence of pathogens in wheat flour can cause human illness: (i) by the consumption of raw dough and (ii) through cross-contamination. The widespread use of wheat products in foods and the occurrence of outbreaks associated with wheat products confirm that eating raw wheat products poses a risk for foodborne illnesses." As processors as well as consumers, these vegetative pathogens must be considered as being potentially present, and with that, we need to have a process to eliminate the organism (baking) and procedures against cross contamination with the raw flour (cleaning).
Journal of Food Protection
https://jfoodprotection.org/doi/full/10.4315/0362-028X.JFP-18-345
Occurrence and Levels of Salmonella, Enterohemorrhagic Escherichia coli, and Listeria in Raw Wheat
Volume 82, Issue 6 (June 2019)