Tomatoes and Produce Safety

March 2021;

Tomatoes are a highlight of summer crops, but they also fall in the category of higher risk produce. This article provides an overview of best on-farm practices for tomato safety. This topic is part of an ongoing series to provide concise, crop specific guidance for preventing food borne illness – with DFI’s own practical tips thrown in.

In the past few decades, contaminated tomatoes have been responsible for large foodborne illness outbreaks associated with Salmonella in the U.S. and beyond (University of Florida, 2012). Tomatoes are most often consumed raw, easily damaged and stored at higher temperatures which more easily allow for pathogen growth – these characteristics make them a riskier type of produce. On-farm best practices for tomato safety those minimize risks (FDA, 2018).

The latest edition of United Fresh Produce Association’s  Commodity Specific Food Safety Guidelines for the Fresh Tomato Supply Chain (2018) shared by the FDA reviews all recommended guidelines of best practices to keep tomatoes safe on the farm.  The guidance highlights open field harvest and packing, the packinghouse, repacking and distribution, and indoor greenhouse production. Below is a summary of key tomato practices from these resources and our own experience here at DFI.

Key Practices:

Harvest:

  1. First, wash hands! Ensure workers handling the produce are not ill and are trained in safe produce handling practices, including proper glove use if gloves are being used.
  1. Do a pre-harvest check to inspect the tomato production area you intend to harvest from. Here at DFI, if tomatoes are found to be contaminated with wildlife feces the tomatoes (and any visibly contaminated leaves and soil) are removed from the field. The area is flagged five feet in both directions and not harvested, and finally the incident is noted in our records. The area is inspected again on the next harvest date. Deterring animal intrusion prevents crop loss!
  1. Ensure all harvest containers and equipment contacting the tomatoes are properly cleaned and sanitized to prevent the spread of pathogens (or cross contamination). Note: wood cannot be cleaned and sanitized – best to avoid wood for storing tomatoes.
  1. Discard any tomatoes that are decomposing or damaged as these are most likely to carry pathogens and promote their growth.
  1. Avoid harvesting a large weight of tomatoes into one container as the tomatoes at the bottom of the container are at risk of bursting from the heavy weight and being exposed to contamination – a quality as well as food safety issue. Tomatoes crushed or otherwise damaged during harvest are discarded at DFI (or later cooked up by staff - cooking kills pathogens!).
  1. Although it is tempting (particularly when faced with a perfectly ripe cherry tomato), eating in production areas should be prohibited as hand to mouth contact spreads pathogens and food-borne illnesses.

Water source, application, and temperature:

Consider how and when you apply water to your tomato crops as well as the source of water, and avoid growing tomato crops in areas subject to flooding (or otherwise exposed to risky adjacent land uses) – our fact sheet on agricultural water provides guidance on this complicated topic.

Because water is a vector for harmful pathogens, at DFI the tomatoes are not washed. Submerging tomatoes in water increases the risk of infiltration of pathogens (particularly if your tomatoes are warmer that the water). Wash water should be potable (no detectable pathogens, such as E. coli), sanitized, and should never be more than 10 degrees cooler than the tomatoes as a rule of thumb (if submerging). It is safer to spray wash tomatoes on a clean and sanitized surface, rather than submerging.

Packaging and Delivery:

All tomatoes should be stored in new or clean/sanitized containers, and in a clean facility. When tomatoes are packaged for sale at DFI, they are put into new boxes, pints, or clamshell containers. If a box is being reused, it is first lined with a new biodegradable bag.

Have a system in place that allows you to track the origin and destination of delivered produce on any given day. In the event that an illness is associated with your tomatoes, you can notify others who received the crop and also hopefully root out the source of contamination.

Storage:

Generally, storage off the ground, covered, away from walls, and at a higher temperature (than greens, for example) promotes tomato quality and safety. At DFI tomatoes are stored in a converted CoolBot shed at around 48 degrees rather than in our walk in cooler at 38 degrees. The higher temperature does increase the potential for pathogenic growth so we are more vigilant about the tomato storage timeframe and actively monitor the produce status.

It’s best to develop a comprehensive food safety plan for the farm, designate someone to oversee its implementation, and train and retrain workers, and keep records. Need assistance with produce safety planning or best practices for specific crops? Contact DFI for a free call or visit, and check out additional resources below.

Moe, J. 2021, Tomatoes and Produce Safety, Desert Farming Initiative - University of Nevada, Reno

Learn more about the author(s)

 

Also of Interest:

 
Know Nevada Insects Youth Exercise: Sphinx Moths
This publication reviews the life cycle, biology and pest management of some kinds of sphinx moths, including the tomato hornworm, appropriate for youth ages 8-15. It It also has educational activities including a fill-in-the-blank and a maze.
Burls, K., Moffitt, M., and Newton, J. 2019, Extension | University of Nevada, Reno FS 19-15
Fruit, Flower and Seed Vegetable Varieties for the Moapa and Virgin Valleys
The purpose of this publication is to emphasize the selected vegetable varieties or cultivars (seeds/plants) that may perform better than others in the Moapa and Virgin Valleys.
Bishop, C. and Stoesser, D. 2013, Extension | University of Nevada, Reno, FS-13-05
Tomato plants in garden
Grow Tomatoes in the Mojave Desert
This week YHEP Instructor, Nicole Hansen shows you how you can grow tomatoes successfully here in the Mojave Desert.
Hansen, N. 2020, Extension, University of Nevada, Reno, YouTube Channel
Common Tomato Disorders Under Desert Conditions
Tomatoes are one of the most popular plants to grow in vegetable gardens and containers in home gardens. Trying to grow them in the desert climate can be problematic. This fact sheet explores ways to help the home gardener diagnose and correct these disorders.
Mills, L., and Johnson, W. 1988, Extension, University of Nevada Reno, FS-88-60
tomatoes on the vine
Combatting Salinity: Evaluation of Tomato Rootstocks Under Mild and Severe Salt Stress
This Extension publication reports the results of University of Nevada, Reno Experiment Station research that tested six different commercial tomato rootstocks and one commercial tomato cultivar for salt tolerance under low, moderate and severe salinity levels.
Bonarota, M.S., Barrios-Masias, F.H., & Singletary, L. 2021, Extension, University of Nevada, Reno FS-21-08
 

Associated Programs

radishes

Food Safety Program

The Initiative's Food Safety Program provides services and resources for growers throughout the state of Nevada. The Initiative partners with the Nevada Department of Agriculture to demonstrate produce safety practices, share guidance and provide training.