Friday, May 13, 2011
WHY ARE GRAPE TOMATOES CONTAMINATED?
An old friend in Australia asked me on my Facebook site whether I thought their grape tomatoes were also unsafe to eat. After I answered the question, something occurred to me. Perhaps she - and some other people - are thinking that the recently discovered Salmonella-bacteria contamination of some U.S. grape tomatoes has something to do with the nature of grape tomatoes themselves. That is, that grape tomatoes are less safe than other kinds of tomatoes.
That isn't the case. As far as I know, grape tomatoes are no more likely to carry pathogenic bacteria. And remember, in the current U.S. outbreak, all the tomatoes came from just one Florida farm which sent them to one Florida packer. Other grape tomatoes from other farms - as far as we know - are currently safe.
Any kind of tomato can become contaminated. Who knows, tomorrow we may hear of a recall of cherry tomatoes or plum tomatoes or Roma tomatoes. Over the years, we have had many incidents of contaminated fresh tomatoes, and Salmonella has been a common culprit. While they are growing, bacteria can get into growing tomatoes through contaminated irrigation water, fertilizer (especially if composting has not been properly done), from birds or insects or wildlife (such as those squirrels which are always trying to take a bite out of mine). While being sorted and packed, workers who are carriers of bacteria, viruses or parasites can also contaminate them. There have been cases when even the washing water was found to be the cause. Although fresh tomatoes are most likely to cause food poisoning, processed, as well as fresh tomatoes can carry bacteria and viruses. In 2010 there was a somewhat unusual small outbreak of Hepatitis A in France caused by sun-dried tomatoes (imported from Turkey). Basically, anything can happen.
So how can you keep eating those delicious fresh tomatoes and still be safe? There is no magic answer. Growing your own would certainly help (the photo is of one of my heritage tomatoes). And if you can't do that, there are studies which have shown that tomatoes still on the vine are safer than those off the vine.