Iowa Public Television


Produce Irradiation is Put to the Test

posted on October 12, 2007

In the wake of the second-largest meat recall in U.S. history, a senior USDA official asserted last week that America's meat supply is "the safest in the world." While the claim may be valid, contaminated foods still find their way to grocery store shelves occasionally and, increasingly, the safety of processed foods and even produce is being called into question.

This week, ConAgra Foods asked stores to stop selling its 'Banquet' and generic brand chicken and turkey pot pies when the products were linked to more than 100 cases of salmonella in 30 states. Earlier this year, the Omaha-based company recalled all of its peanut butter after it was blamed for a salmonella outbreak that sickened more than 600 people in 47 states.

Last year's deadly outbreak of E. coli traced to California spinach prompted experts to reconsider the safety of domestic fruits and vegetables. But a Midwestern company believes it has the solution to food-borne pathogens in produce. As Andrew Batt discovered last spring, the head of the company is so sure of his product that he willingly consumes a potentially lethal strain of E. coli as a testament to the power of irradiation.


The produce aisle at your local grocery store is far more plentiful than the fresh fruit and vegetable aisle of the early-20th century. There is relatively year-round access to a wide variety of citrus, tomatoes, apples, and lettuce. But recent events have cast a shadow over the safety and wholesome perception of fresh produce.

Last fall, many Americans discovered a disturbing gap in our nation's food security…

The fall 2006 outbreak of e coli, originating from California spinach fields, was blamed for three deaths and illnesses in more than 200 people. Today, the search to ensure the safety of America's produce industry is ongoing. Government officials and private industry leaders have yet to reach a consensus on what methods can guarantee consumer safety.

Harlan Clemmons, Sadex: "…e-coli O157:H7 is easier to kill than let's say bacteria or salmonella."

Harlan Clemmons says last fall's outbreak could have been prevented. He claims that the technology to protect consumers already is used on many beef products across the country and is 100% safe.

Clemmons, who operates the Sioux City, IA, corporation Sadex, says the industry's answer is electronic beam irradiation, or E-Beam.

Based on technological advances during the Reagan Administration's Star Wars program of the 1980's, food irradiation is commonly used to zap meat products with super-charged beams of radiation. Clemmons compares the machine to a highly-concentrated microwave oven that consumes the energy equivalent of a 15-home city block.

The e-beam sends electrons flying through food products at virtually the speed of light, killing dangerous bacteria while leaving food safe to eat and visibly unharmed.

Harlan Clemmons, Sadex: "…it will have the same flavor, it will have the same texture, crunchiness, um, smell, everything is basically the same. You won't notice anything different between treated product and untreated product."

Clemmons' has so much faith in his e-beam machine he proposed eating spinach intentionally laced with e coli as long as it was irradiated at his Sioux City, Iowa, facility. Market to Market took his request for e coli-laced spinach to Midwest Labs, an independent commercial laboratory in Omaha, Nebraska.

Technicians at Midwest Labs took three store-purchased bags of spinach, using two bags as e coli test samples and the third as a controlled "clean" sample.

The O157:H7 strain of e coli was prepared in a common spray bottle by Midwest Labs and applied to two full bags of spinach. The potentially lethal strain, nearly identical to last fall's virulent California e coli outbreak, could cause serious health complications including kidney failure.

Dr. Jerome King, Midwest Labs: "…it's a known pathogenic organism and it can kill people, and yes, the number of people that are affected by it and a number of people that die from it were relatively few, but yet when you consider that, it is something that potentially could be addressed and could be changed and people are looking for safe food in that respect…"

Lab technicians at Midwest Labs processed and sealed three bags of spinach in a Styrofoam container. Market to Market then transported the spinach 100 miles north to Sioux City, Iowa, where Sadex employees were ready for processing.

After sending the spinach through the Sadex irradiation machine, company staff took the produce to Harlan Clemmons.

After rinsing the spinach with water and applying scoopfuls of Thousand Island dressing, Clemmons remained true to his word – eating produce laced with e coli and sent under a concentrated beam of radiation.

Harlan Clemmons, Sadex: "It tastes like spinach. There is no difference and it's still crunchy and fresh."

Despite Clemmons' assurance of safe produce, we took the irradiated spinach back to Midwest Labs for further tests.

The lab report was conclusive…spinach laced with e coli by Midwest Labs had more than 100 million individual e coli bacteria before it went under the Sadex e-beam. After the irradiation process, there were only 100 bacterial organisms in the spinach sample – a dramatic 99.999% drop in e coli.

According to Dr. Jerry King, the lab's quality control director, the remaining trace of e coli is far too low to affect a consumer's health.

Dr. Jerry King, Midwest Labs: "In terms of the science behind E-beaming and the, the method that E-beam works, I feel it to be a very safe and a very effective form of treatment of foods and removal of bacteria from food."

The results were NOT a surprise to Harlan Clemmons, who consumed the spinach without hesitation and did not suffer any health ailments following our visit. But Clemmons does have a problem – irradiation has not been approved by the FDA for produce. Politicians and government officials are still wrangling over the technology's future application.

Charles Sweat, Natural Selection Foods: "We have faced many challenges in our 23 years but none as great or as important as this."

In April, the House Energy and Commerce Committee held hearings to determine a solution for produce safety.

Sweat: "At this point we don't have a kill step as that would be defined for fresh produce. That is one of the reasons we've moved forward with our testing protocols is to help to detect it, to prevent it from entering the chain of commerce."

Congressman: "Now, irradiation I guess can be used in meat products but can irradiation be used in vegetables?"

Sweat: "Irradiation has not been approved for use by the FDA for fruits and vegetables."

The lack of a kill step for produce, such as either irradiation and grilling for beef, is why Sadex would like to offer its services to the fruit and vegetable industry. And in recent months, the Food and Drug Administration has shown growing support for certain fruit and vegetable products.

But consumer groups have warned that irradiation is harmful, unsafe, and in some cases damages the nutritional composition of produce. Harlan Clemmons disagrees…

Harlan Clemmons, Sadex: "People claim that there will be cell damage and there would be at higher doses, but if a dose level just needed to get a four or five log reduction of pathogens, there's no cell damage, no damage to the product. It's still crunchy um, still tastes like spinach. We tried carrots, mushrooms, they all taste the same. There's no physical damage appearance damage or anything with regards to that."

While Clemmons hopes his irradiation technology for produce will achieve FDA approval, any future change is far too late to help the hundreds of sick individuals and three deceased consumers from last fall's outbreak.

For Market to Market, I'm Andrew Batt.

Tags: agriculture California food food safety Iowa news radiation salmonella science technology vegetables