Examples for averted hazards by QMRA. According to the QMRA, a microbiological risk was found in a Spanish field with cabbage lettuce after strong rainfalls and floods in 2012 (QMRA question No 3). The original sample taken from the lettuce contained Salmonella spp and the action plan was activated. The supply chain was informed and the field was immediately blocked. Further samples were taken according to the control plan (lettuce, soil, and water from five subareas) and all five samples were positive for Salmonella spp: therefore, a nonpoint source contamination existed. The irrigation water from a river nearby was identified as the source of contamination: the river was highly contaminated with waste water and dead animals from neighboring farms.
In 2014, a microbiological risk was found in a Moroccan parsley field. A cow-farming unit existed near the field without an enclosure (QMRA question No 2). The original parsley sample contained STEC (E. coli 0103) but only one sample from the tests and one soil sample was positive. Both positive samples were from the same subarea nearest to the cow-farming unit. The irrigation water sample was negative and a partial contamination was found in the subarea due to animal feces.
In 2015, Listeria monocytogenes was found for Batavia in Italy when an undocumented (date of application, microbiological sampling) use of organic fertilizer had been observed (QMRA Question No 4). After blocking the field, all control samples were negative and a point source contamination of the field was acknowledged. The harvest could be continued.
Conclusions
The microbiological condition of food is one of the most critical elements of food safety, especially for fresh fruits and vegetables. The entire supply chain of fresh fruits and vegetables is highly time sensitive yet microbiological controls take some time for analysis. Unfounded actions could endanger human health and/or the supply chain. This new risk-based evaluation in the field facilitates a safe and convenient risk assessment of the microbiological condition of fresh crops at an early stage in the supply chain. Examples have demonstrated the reliability of the system, which comprises risk evaluation, action and a control plan. The QMRA saves time and cost but should be administered only by well-trained technicians. Sampling must be performed according to standardized and accredited methods.
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Lampe is a geo-ecologist at Analytica Alimentaria GmbH. Reach him at [email protected]. Hidalgo Palanco is a biologist at the company. Reach him at [email protected]. Fernandez Caro is agricultural engineer at Analytics Alimentaria. Reach him at [email protected]. Dr. Krause is a physicist at the company. Reach him at [email protected].
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