Durk Pearson & Sandy Shaw’s^®
Life Extension News^TM
Volume 15 No. 3 • June/July 2012

As you have probably read, there is a rapid increase in the number and severity of foodborne illnesses due to pathogens such as Escherichia coli, Salmonella spp. and Listeria monocytogenes.¹ A new paper¹ gave a breakdown on the types of produce most likely to carry these pathogens. “Between 1998 and 2006, 5 types of commodity produce comprised 76% of produce-related outbreaks: (1) lettuce/leafy greens (30%), (2) tomatoes (17%), (3) cantaloupe (13%), (4) herbs (basil, parsley, 11%) and (5) green onions(5%).”¹

The researchers purchased vegetables (romaine lettuce, iceberg lettuce, perilla leaves, and sprouts) at a local food store and prepared samples, cutting the veggies with an alcohol-sterilized knife, pathogens were pipetted on the samples (S. Typhimurium, S. aureus, L. monocytogenes, or E. Coli (which were then dried in a fume hood for 1 hour), and inoculated samples then placed into sterile plastic bags, which were stored at 4 degrees C for 3, 6, 9, 12, or 15 days or at 15 degrees C for 1, 2, 3, 5 or 7 days.

The results indicated that in order to prevent the growth of foodborne pathogens, minimally processed vegetables should be stored at 4 degrees C.

The only time we feel comfortable eating raw tomatoes is in the short growing season here in central ­Nevada, when we grow our own. Otherwise, we eat canned tomatoes or cooked fresh tomatoes.

1. Tian et al. Survival and growth of foodborne pathogens in minimally processed vegetables at 4 and 15 degrees C. J Food Sci 71(1):M48-M50 (2012).