Durk Pearson & Sandy Shaw’s®
Life Extension NewsTM
Volume 15 No.
3 • June/July 2012
How to Store Minimally Processed Vegetables
to Avoid Survival and Growth of Pathogens
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. A new paper 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%).”
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.
- 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).