“WASHINGTON – Pick a tomato in the blazing sun and plunge it straight into cold water. If that happened on the way to market, it might be contaminated. Too big of a temperature difference can make a tomato literally suck water inside the fruit through the scar where its stem used to be. If salmonella happens to be lurking on the skin, that’s one way it can penetrate and, if the tomato isn’t eaten right away, have time to multiply.

That doesn’t mean people shouldn’t wash their tomatoes — they should, just probably not in cold water.

But as the Food and Drug Administration investigates the nation’s outbreak of salmonella from tomatoes, the example shows the farm isn’t the only place contamination can occur — and checking things like water quality and temperature control in packing houses and other supply stops is one key to safety.”

This raises the question of what sorts of water quality parameters packing houses should monitor on a regular basis.

Sanitizer and Disinfectant Levels — If the water used to wash, rinse and cleanse the tomatoes contains enough sanitizer, then theoretically no salmonella or other forms of bacterialogical contaminants could survive in the water. No contaminants in the water means no contaminants that a tomato could ‘suck up’ if submerged in cold water.

“Water is an automatic first suspect. Was clean water used to irrigate, mix pesticides sprayed on crops, wash down harvest and processing equipment, and wash field workers’ hands?

Then in packing houses, tomatoes often go straight into a dump tank, flumes of chlorinated water for a first wash. 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, also part of FDA’s tomato initiative.

Beyond packing houses, the industry points to cases where suppliers were shipped unwashed, warm tomatoes and dunked them in ice-water baths to firm them for further processing.

Another question: How often does the water have to be changed? Dirt, leaves and other sediment reduce the chlorine’s effectiveness.”

Produce handlers and packing houses could reduce the chances of accidentally passing fresh produce through improperly disinfected wash water by implementing test procedures and protocols which make use of simple, inexpensive chlorine test strips such as SenSafe^TM Free Chlorine Water Check, a product approved by the USEPA and by several states for drinking water compliance monitoring.

The manufacturer of this product also has dip-n-read test strips capable of detecting chlorine concentrations as high as 2,000ppm and as low as 0.005ppm.

Article Written by MIKE STOBBE, AP Medical Writer.

ATLANTA – An outbreak of salmonella food poisoning first linked to uncooked tomatoes has now been reported in nine states, U.S health officials said Tuesday. Lab tests have confirmed 40 illnesses in Texas and New Mexico as the same type of salmonella, right down to the genetic fingerprint.

An investigation by Texas and New Mexico health authorities and the Indian Health Service tied those cases to uncooked, raw, large tomatoes.

At least 17 people in Texas and New Mexico have been hospitalized. None have died, according to the U.S. Centers for Disease Control and Prevention.

Another 30 people have become sick with the same Salmonella Saintpaul infection in Arizona, Utah, Colorado, Kansas, Idaho, Illinois and Indiana. CDC investigators are looking into whether tomatoes were culprits there, too.

In Texas and New Mexico, raw large tomatoes ” including Roma and red round tomatoes ” were found to be a common factor in the 40 illnesses. But no farm, distributor or grocery chain has been identified as the main source, said Casey Barton Behravesh, a CDC epidemiologist working on the investigation.

“The specific type and source of tomatoes is under investigation,” she said.

Salmonella is a bacterial infection that lives in the intestinal tracts of humans and other animals. The bacteria are usually transmitted to humans by eating foods contaminated with animal feces.

Most infected people suffer fever, diarrhea and abdominal cramps starting 12 to 72 hours after infection. The illness tends to last four to seven days.

Many people recover without treatment. However, severe infection and even death is possible. Infants, the elderly and people with weakened immune systems are at greatest risk for severe infections.

In Texas and New Mexico, the patients ranged in age from ages 3 to 82. Of the 40, 38 were interviewed. Most said they ate raw tomatoes from either stores or restaurants before becoming ill between April 23 and May 27.

Another 17 cases are under investigation in New Mexico, CDC officials said.

As a result of this recent outbreak of illnesses related for foodborne contaminants, many restaurants and supermarkets have pulled tomatoes off the shelf and/or stopped serving them until they hear an official OK from Federal, State and Local Health Officials.

So if you thought water testing had very little to do with the handling and processing of fresh produce such as tomatoes, you thought wrong. At each step of the handling process the quality and nature of the water used to sanitize/disinfect, wash, rinse and clean the dirt off of fruits and vegetables needs continuous monitoring.

Monitoring Free Chlorine Levels in (Produce) Wash Water:

Many fruit and vegetable packing houses rely upon the Sensafe™ Free Chlorine Water Check test strips with a detection range of 0-6ppm to let them know if the wash water contains enough free chlorine residual to effectively keep their finished product free of contaminants.

Monitoring Free Chlorine Residuals Used to Wash Equipment:

Health officials on every level require the operators of fruit and vegetable processing plants to clean off their machinery with a strong disinfectant solution. WaterWorks™ Free Chlorine (High Range) test strips have a detection range of 0-120ppm, a range well suited for monitoring the free chlorine residual levels in the solutions used to hose down (wash) the equipment in a fruit and vegetable processing plant.

Making Sure No Chlorine Remains on the Fruits and Vegetables:

The presence of chlorine residual on fresh produce leads to premature rotting of the product so workers in fruit and vegetable processing plants check the total chlorine levels in water used in the final rinse stage with products like the SenSafe™ Total Chlorine test strips before allowing the produce to go into its final packaging.

“In 2007 California farmers came together to raise the bar for food safety. As a result the California Leafy Green Products Handler Marketing Agreement (LGMA) was formed. Members of the LGMA are working collaboratively to protect public health by reducing potential sources of contamination in California-grown leafy greens.

To date nearly 120 handlers, representing over 99% of the volume of California leafy greens, have joined the LGMA. These companies have committed themselves to sell products grown in compliance with the food safety practices accepted by the LGMA board. LGMA membership requires verification of compliance with the accepted food safety practices through mandatory government audits. These food safety practices were developed by university and industry scientists, food safety experts and farmers, shippers and processors. California leafy greens are now grown under a unique system that has become a model for leafy green growers in other states.” ( source )

What does any of this have to do with water testing? Quite a bit, actually.

• All fresh produce gets rinsed several times during processing with water containing some form of disinfectant. At the end of each rinsing stage, the water must used must get tested to make sure it still has a certain amount of residual disinfectant. This helps to ‘guarantee’ the cleanliness of the product.
• The machinery and equipment (bins, conveyor belts, cutting tools, etc.) used during the processing of the fresh produce must get washed down thoroughly with water containing a certain concentration of sanitizer and then rinsed clean w/ sanitizer-free water until all traces of sanitizer have been removed.
• Gloves, boots, etc. worn by the staff working in produce packing houses must get sanitized with, and later rinsed clean of, sanitizers.

Commonly used sanitizers and disinfectants in the food preparation/processing industries include chlorine, chlorine dioxide, quaternary ammonia, hydrogen peroxide, and ozone.

In areas where water does not freely fall from the sky at produce growers’ commands, long lines of pipe and hose run deep into the hearts of crop fields so that all the plants may drink… water.

For the most part, all fruits and vegetables sprout up from, and spend most of their life in and around dirt, mud, dust and soil — until they get picked and thrown in bins for ‘processing’. At that point they get washed off with… water mixed with various sanitizers/disinfectants such as ozone, chlorine, chlorine dioxide and quaternary ammonia.

Then, once the produce reaches a packing house, and before the fruits and vegetables get chopped, sliced, diced, cubed, quartered and/or canned, they get thoroughly washed with… water containing sanitizers/disinfectants and then rinsed one more time with pure… water so that they have no traces of the potentially harmful (if ingested) sanitizers/disinfectants left on them.

So there you have it, folks. Water plays an integral part of the produce life cycle. Therefore, do you not think it important to monitor the quality of the water used to clean, rinse and process your produce?

So What Parameters Typically Get Tested?

Total Hardness — Very important for any farming or agricultural activity where water gets distributed via some sort of irrigation/watering system. High hardness levels can lead to deposits forming in the nozzles and over time the nozzles may become completely clogged. Find total hardness test strips

pH — Some folks question the importance of monitoring pH but ask people who grow grapes used for the production of wine and you’ll discover that variances in pH affect the taste of a grape dramatically… and that changes the taste and drinkability of the wine. Find pH test strips

Sanitizers/Disinfectants — At the washing stage produce handlers test their water to make sure it contains enough sanitizers/disinfectants. Then, at the rinsing stage, they test their water again to make certain the produce does not have any sanitizer/disinfectant residual on it. The presence of leftover chemical cleaning agents on the produce would lead to premature spoiling. Find chlorine test strips, ozone test strips, chlorine dioxide test strips and peroxide test strips.