I spent the day is a well-run, informative, conference sponsored by Fresh Express (never sued them). The science was interesting and well presented. The bottom line however is there is far more research needed and the risks to consumers are still quite real in the consumption of “ready-to-eat” products. Here are some of the highlights from the scientists:
1. Contamination can spread during washing, cutting in the fields and the tumble drying of greens
2. Chlorinated water alone isn’t enough to kill the pathogens.
3. Some varieties of spinach with textured leaves have greater potential for harboring pathogens than smooth-leaf varieties.
4. E. coli can paralyze pore closures (somata) on spinach leaves and allow bacteria into the plant.
5. Compost used inorganic operations can retain traces of live E. coli cells that can reconstitute under the right conditions.
6. Spinach and lettuce harvested on hotter days are more likely to create an environment for pathogen growth.
7. Lower product temperature, especially during transportation, lowers risk of bacterial growth.
8. Flies or other insects can excrete bacteria in their fecal droplets.
9. It seems apparent that the E. coli bacteria is not absorbed by the roots into the plant structure.
OK, not much good news here. The only two areas that seemed hopeful was that some research on E. coli transmission found ozone gas is faster and more effective than chlorinated water at sanitizing leafy greens. And, although not mentioned until the last hour, irradiation of leafy greens can make food safer.
Bottom line – more work to do.