More On Tomatoes and Salmonella

Over the last few weeks we've been hearing about salmonella in our tomatoes. Here's some more news that's disconcerting. Apparently washing produce doesn't necessarily remove salmonella. According to Lauran Neergaard, AP Medical Writer, if a tomato is warm and the water rolling over its surface is cold, then the fruit will absorb that water through any opening in the skin including the stem scar. If there is salmonella present on the tomato skin, it can enter the fleshy part of the tomato and the bacteria multiplies. Ms. Neergaard suggests we should wash our tomatoes, but not in cold water.

To guard against salmonella washed into the water in turn being sucked into the tomatoes, producers often keep wash-water 10 degrees warmer than the incoming crop, says food-safety scientist Keith Schneider of the University of Florida...

In fact, salmonella may be particularly hard to prevent in a variety of crops because birds, reptiles and amphibians carry it - the same reason children should wash their hands after handling a turtle, iguana or frog. The tomato industry's guidelines already advise surrounding fields with bare soil "buffer zones" to discourage reptiles.

This is the 14th salmonella outbreak associated with tomatoes since 1990.

The FDA has launched a Tomato Safety Initiative to learn more about how salmonella gets onto and inside tomatoes. Industry practices in Virginia and Florida (the origin of several previous outbreaks) are being studied and Florida's agriculture department will begin enforcing so-called "tomato best practices" on July 1st. The FDA is also asking for the authority to set preventative controls for growers and suppliers of foods linked to repeated outbreaks of serious illness, such as tomatoes and leafy greens. Congress hasn't yet acted on that request.

Ms. Neergaard doesn't mention groundwater contamination as an issue, as discussed in this New Scientist article:

The bacteria probably come from groundwater contaminated with animal faeces, he says. Once Salmonella gets on and into a tomato, the fruit acts like an incubator. Bacteria divide even in the cool temperatures of packing houses. "If you get a few samples into the internal tissue, then they will grow for sure."

At the moment there don't seem to be any clear cut answers as to how to prevent this from happening. But for now, wash your tomatoes in warm water.


  1. “At the moment there don’t seem to be any clear cut answers as to how to prevent this from happening.”

    Really? Veganic gardening and hydoponic gardening using filtered water don’t prevent bacterial contamination from animal feces? Cause I think they might 🙂

  2. Actually I believe Elaine is on to something – I recently saw on tv vertical hydroponic gardening plans being considered for urban areas. These “buildings” would house floors of food – in essence we may someday be growing bananas in Manhattan…. Hydroponics is being considered on floating vessels – taking advantage of solar energies….. traveling through space of course would be sustainable with hydroponics as would utilizing arid lands here on earth. …. even the arctic (if it doesn’t melt away first….. )

    I know the animal (meat) agriculture is so 20th century and passe’ as 8 track tapes. Industrial hydroponic food production and gardening is the way to a sustainable future:

    Not only is hydroponic food production on an industrial scale practical – it’s part of the answer to global hunger and would help reverse the ill-effects of carbon emissions. And of course, best of all…. the final blow to animal/meat agriculture. 🙂

  3. Hi Bea,
    The hydroponic thing is interesting, but are we there yet? Also, it’s probably geographically dependent. I live in S.Cal. I cannot imagine hydroponics would be a viable option here when we’re already experiencing water shortages.
    It would be interesting if the vertical farm thing was moving forward. There was a hoax involving a vertical farm in Vegas back in January.
    I guess I’m skeptical that these alternatives will be viable in the near term. We’ve been aware that we need to wean ourselves from petroleum for decades… and powerful lobbies have kept us from actually making progress until now. It feels to me like the same forces are at work to keep the status quo in our farming.
    Interestingly, I just read an article tonight that the Phoenix lander has sent back data from Mars — some Martian dirt has the same basic chemistry as garden soil. So, after we destroy our planet, we can grow food on Mars (kidding).

  4. Hi Lane…. You’re right, we’re no where near hydroponics on the scale necessary to sustain for the future. And doesn’t look like petroleum is at an end till the last drop is sucked out of the earth. It appears that’s just the way we do most things: “eleventh hour, 59th minute, 59th second” kind of attitude. But turnips of Mars! now that’s an awful lot of food miles to travel.

  5. Hi Elaine,
    Thanks for the link. Upon reading that article, it looks as if they may still be the problem.

    “Last week, health agencies tracked some of the implicated tomatoes to farms in Florida and Mexico, but officials stressed that the contamination could have happened in transit or at a packing station.
    The FDA has cleared 41 states and several Mexican states and parts of Florida as the growing regions that produced the possibly tainted tomatoes. But Acheson said the agency was still tracing distribution chains through areas included on the list.
    “The longer this goes on, the less likely it’s all originating from a single farm source,” he said.
    The repacking process, which causes tomatoes to be shuffled among tomatoes from different farms, is making the investigation especially difficult, Acheson said.”

    It’s certainly possible for other produce to transmit these bacteria. Regardless, I’m not all that comforted by the FDAs uncertainty. If they can’t find the cause, it seems more likely that this will happen again, and again…

  6. Organic Hydroponics have been around for a while. the new thing is Veganic Hydroponics. Now if only we could get the growers and grocers to leave the plants alive in solution until the consumers buy them.

  7. This guy is correct. I’ve been grwnoig tomatoes and peppers for almost a decade, and his advice will save you years of screwing around. If you can afford to not be cheap, don’t be cheap. Make CRW (concrete reinforcement wire ) cages or get the Texas Tomato Cages. CRW cages rust, are hard to store and look like crap after a year or two, but they work well. The Texas Tomato Cages have a high initial cost, but will save you time and money in the long run. Plus, they don’t rust.

Leave a Reply

Your email address will not be published.