Center for Infectious Disease Research and Policy reports
Producers of sprouts should add more food safety steps throughout the production chain to lower the risk of the kind of contamination that triggered a widespread Escherichia coli outbreak in Europe earlier this year, the European Food Safety Authority (EFSA) said in a report released yesterday.
The EFSA’s Panel on Biological Hazards said it is difficult to limit bacterial contamination of seeds used for sprouting in the face of many risk factors, but called on producers to step up their efforts. The panel also said no reliable method has been found to decontaminate all types of seeds without reducing germination or yield.
Recent article published in Journal of Food Science 2011 evaluated the effectiveness of calcinated calcium spray on Escherichia coli 0157 H:7 87-23 population on radish sprouts. The results indicate that a 200 ppm NaOCl soaking followed by 0.04% calcinated spray resulted in no microbial growth after a 72 hour sprouting, while maintaining a high germination rate. However, the study reveals that despite treatment method, most of the inoculated Escherichia coli 0157 H:7 87-23 cells accumulated on the sprout roots and biofilms formed on sprout surfaces.
Sprouts are inherently dangerous as there is no proven method to effectively eliminate pathogenic bacteria during sprouting. There appears to be limited steps sprout producers are able to take to reduce the risks associated with such a product. As such, the public needs to be adequately informed on the risks of consuming sprouts, in particular, vulnerable populations such as pregnant women.
The EFSA risk assessment on pathogenic bacteria in seeds and sprouted seeds was prompted by the enterohemorrhagic E coli (EHEC) outbreak centered in Germany this past spring and summer. The outbreak, which involved at least 3,134 cases and 40 deaths, was traced to fenugreek seeds imported from Egypt. The finding caused the EFSA to warn consumers not to eat any sprouts for a time; the warning was canceled on Oct 3, after the implicated seeds were off the market.
Decontamination of seeds before sprouting is used as an additional safety measure in some European Union states, the panel observed. However, "To date, no method of decontamination is available to ensure elimination of pathogens in all types of seeds without affecting seed germination or sprout yield."
Fransisca, L., Zhou, B., and Feng, H. The Effect of Calcinated Calcium and Chlorine Treatments on Escherichia coli 0157 H:7 87-23 Population Reduction in Radish Sprouts. Journal of Food Science. Vol. 76, Nr. 6, 2011