Food Irradiation Updates

Published by Ronald F. Eustice and sponsored  by GRAY*STAR Inc.
June  2014
Food Irradiation Update is published monthly by Ronald F. Eustice, a food quality & safety assurance consultant based in Minneapolis and Tucson. He can be reached at: and at 612.202.1016.

National media coverage of food irradiation continues to grow as new approvals are made and sales volume increases. There is renewed and growing interest worldwide about irradiation as a food safety tool, a shelf-life extender and as a phytosanitary treatment.
In May we told you about coverage by the Washington Post. The latest media coverage occurred June 9th on FOX News. We expect more media attention in the future. While we would like to change a few things that were said in the FOX segment, the overall message was positive.Click on the image to watch the FOX News segment on food irradiation.
Mr. Stein was asked by the Institute of Food Technologists (IFT) to address the current and future commercialization of food irradiation including the main issues inhibiting its widespread use.
 Except for those within food companies that are having their products routinely irradiated, we haven't heard much about food irradiation over the last decade. However, recently there seems to be a resurgence of press articles and even government approvals related to irradiating food. What's going on?

In the 1980s, the U.S. Food and Drug Administration (FDA) made a significant step by approving the irradiation of spices (more accurately, dehydrated aromatic vegetable substances) to a maximum dose limit of 30 kGy and fresh food products to a maximum dose limit of 1 kGy. These two applications are very different from one another and require different equipment. Furthermore, one is for perishable product and the other is for non-perishable product, requiring different product handling and logistics.

At the time of these approvals, a mature irradiation industry was already in place. But that industry was centered on the processing of non-perishable products above 10 kGy, such as medical devices. Therefore, it was relatively easy for the spice industry to take advantage of the existing irradiation infrastructure. Today, a majority of spices are irradiated on a regular basis. However, most people don't think of spices when they think of food. They think of perishable foods such as meat and vegetables.

Perishable foods, by definition, have significant logistical challenges. Irradiating perishable food requires irradiators that are suited to delivering a dose that is only a fraction of that for non-perishable foods. Only just recently have irradiators and service irradiation facilities specifically designed for perishable products become available to the food industry.

An irradiator specifically designed for perishable foods was recently installed inside an existing cold storage food warehouse in Gulfport, Miss. It is processing a significant percentage of fresh, live, Gulf oysters as a Post-Harvest Process (PHP) to minimize the public health threat from Vibrio Parahaemolyticus and Vibrio Vulnificus. Located in the geographic center of the Gulf, inside a cold storage facility, it became easy for oyster harvesters to take advantage of the irradiation process without significant modifications in their logistics. The costs are minimal when compared to the benefit of producing a safe live oyster even in off-season months.

An impact is also being made on the import of previously quarantined fruits. The irradiator in Gulfport is just starting to irradiate imported fruit to ensure that they do not contain viable insect pests that could threaten U.S. domestic crops. The initial volumes being processed are small and not yet significant from an industry-wide perspective. However, since the specific fruits have no other approved method to allow entry, it represents 100% of their niche of the food industry. Another facility, using an irradiator identical to that in Gulfport, has recently opened in Hawaii to export fruits and vegetables, through quarantine, to the mainland. Soon both facilities, and perhaps more, will allow the export of U.S. agricultural products to countries that have similar quarantine restrictions.

The use of both of these facilities is growing at a rapid pace. This is paralleled by other segments of the food industry re-evaluating the use of irradiation for their products. As new irradiators are commissioned for specific food processes, they will be available for other segments of the food industry to explore the potential of irradiating products. This, in turn, will lead to even more facilities. Similarly, as the capabilities to irradiate certain foods become more prevalent, the regulators have more stimulus to allow the irradiation of new food products. In April, the FDA finally approved the irradiation of crustaceans that had been petitioned back in 2001.

You cannot irradiate a commercial product without the equipment and infrastructure in place. It was already in place for spices in the 1980s. It is now just starting to be available for fresh foods. It is not that food irradiation is back. It has always been here, but for limited and relatively small volume products. There is a growing capability to irradiate perishable food, which is re-kindling an interest in food irradiation.

Russell Stein
Vice President, GRAY*STAR, Inc.

"Irradiation is too effective and irradiation is not effective enough."

"Irradiation is too effective and irradiation is not effective enough."


This statement is incorrect.  The effects of irradiating food are proportionate to the dose, and the dose is controlled during the process.  Therefore, the effectiveness of irradiation is defined for each specific application.


This myth appears to be two myths that are strung together for convenience, but that is not the case.  The myth is based on the argument that irradiation is too effective because, since it can be used to kill all pathogens, then it will be used to replace all Good Manufacturing Practices including sanitation.  And, at the same time, if it is not used to kill all of the pathogens, then it is not effective enough.


There are many methods for reducing pathogens in food.  A specific method only kills a percentage of the pathogens when properly applied.  This is common for chemicals used during the processing of the food, and/or as additives applied to the food.  For example, washing the food in highly chlorinated water will reduce the pathogens, but not eliminate them.  There are also several methods for eliminating pathogens in food.  For example, canning, when applied properly, will kill all of the pathogens.  We do not hear that pathogen reduction techniques "are not effective enough" and, similarly we do not hear that pathogen elimination techniques "are too effective".  For most processes, there are threshold conditions.  If the conditions are not met, such as chemical concentration or temperature or pressure etc., then the effect on the pathogens is inconclusive.


Irradiation has its advantages and its disadvantages.  One clear advantage is that the effect on pathogens is proportional to the irradiation dose to those pathogens.  However, the correlation of the effect from the dose is not linear, but logarithmic.    If a specific dose reduces the pathogen population from 100 to 10 in a sample of product, and you double that dose, the pathogens are reduced to 1.  If you triple the original dose, then there would only be 0.1 pathogens surviving (or one pathogen in ten samples of product).  We refer to the dose required to reduce the population of a specific pathogen by a factor of 10, the "Dvalue", the letter "D" representing "decimal reduction", or factor of 10.  If you give a product the Dvalue dose, you will reduce the pathogen by one "log" (another way of saying a factor of 10).  Therefore doubling the dose results in a "two log reduction".  Tripling: a "three log reduction", etc. 



Consequently, you can customize the dose based on the population of target pathogens.  You can use the process as a pathogen reduction technique by applying perhaps a one log reduction (a 90% effective kill) or two log reduction (99%).  This may be employed in conjunction with other pathogen reduction techniques.  Or, you can use it as a technique to kill all of the pathogens, "sterilizing" the product similar to canning; a twelve log reduction (99.9999999999%).  More commonly, the process is used to "pasteurize" the product, which is typically a five log reduction (99.999%).


The cost of the process is somewhat proportional to the dose.  The higher the dose the higher the cost.  Also, if there are any negative effects on the product from irradiation there may be a dose that cannot be exceeded.  Thus, there are definite advantages in keeping the dose as low as practical as long as they are sufficient for achieving the intended purpose of the irradiation.  For products that have a pathogen requiring a dose that has a negative effect on a specific product or a dose that costs too much for the market to bear for that product, then the process will not be used on that specific product.


Is irradiation too effective?  Is irradiation not effective enough?  Irradiation is as effective as it needs to be.


Russell N. Stein



Note:  Mr. Stein has prepared this and all of the previous Myths of the Month.  If you have any questions or comments on the Myths of the Month, feel free to contact him directly at:

Read more here....


Losses linked to Wolverine Packing Co. go deeper than recall; BarfBlog, By Ben Chapman (June 2, 2014)

1.6 Million Pounds: Largest Beef Recall in Recent Times

A couple of years ago I heard a retailer food safety dude tell a group of farmers that his team keeps track of companies linked to illnesses and recalls. The buyer paid attention to how the incident was handled, especially watching for an expanding recall (indicating poor sanitation or traceability) and any public comments by the company. The collected info was used to evaluate whether they would buy from the supplier in the future. 

Being linked to tragic illnesses usually results in more than just writing off product; fallout also often includes a loss of trust within the buying community and a poor reputation with consumers. And that's what I told Bill Shea of Crain's Detroit Business  when he asked what might be ahead for Wolverine Packing Co.  

Meat Recall Costs are Huge (Read More) ....

Research shows that 2% of all cattle may be E. coli Super Shedders; BarfBlog, By Doug Powell (June 6, 2014)
Approximately 2% of all cattle are E. coli super shedders.

CLAY CENTER, NEBR: Research shows that about 2% of cattle in feedlots and those on pasture, may be E. coli  "super shedders." Scientists have coined this term to describe cattle which turn out high levels of pathogenic organisms. Using studies by researcher Terrance M. Arthur and his colleagues at the USDA Agricultural Research Service Roman L. Hruska US Meat Animal Research Center in Clay Center, Neb., experts hope to provide a scientifically sound basis for new and effective strategies to curb shedding of this bacterium.


Arthur and his co-workers have designed and conducted studies of 6,000 head of feedlot cattle and more than 13,000 manure, hide and carcass samples. To discover more about supershedding, Arthur and his colleagues gathered data representative of the entire U.S. cattle population to estimate the incidence of supershedding. Their analysis determined an average incidence of 2%. E. coli Super Shedders...

Pakistani Mango Growers Slice into India's Market; News Pakistan (May 26, 2014)

LAHORE: It has been recently revealed that Pakistan, this year, will be exporting more mangos as compared to India. Both the countries are famous for the delicious yellow fruit but due to the ban which has been levied upon India by the European Union, Pakistan will be the sole provider of mango this time round.

Both the countries are famous for growing 'the king of fruits'. Economically, however, mango is something where Pakistan has an edge over India. Last year Pakistan managed to export 100,000 tonnes of mango while India only managed to sell 56,000 tonnes of mango. This earned Pakistan $48.6 million while India managed to make $44.6 million.

The ban on India has been levied because one embargo, which was delivered to Europe, contained fruit flies. This did not only ruin fruit, but also four different types of vegetables.

Visit by New Zealand delegation to India to inspect irradiation facilities in Maharashtra is expected to boost mango exports (May 30, 2014): 

MUMBAI: A visit by a delegation from New Zealand to India last week to inspect irradiation facilities in Maharashtra is expected to boost mango exports. 

"The delegation was shown vapour heat treatment ( VHT) facilities in Mumbai and another private facility set up by an exporter Namdhari Exports and the team was pretty satisfied," Dr Sudhanshu, DGM, regional head (West) Apeda, told FE.

Around 30 consignments have already been sent to NZ and by July 15, we expect larger numbers, he said. Currently, India has only one irradiation unit in Maharashtra with a processing capacity of 10-15 MT a day.

Indian exporters who wish to export mangoes to NZ have to get the fruit treated at these facilities. Irradiation has as gained significance in light of the ban imposed by the European Union on the import of Indian mangoes. Irradiation Boosts Indian Mango Exports to New Zealand (Read more here)....

New Zealand to import Vietnam Dragon Fruit; Vietnam News Service (May 29, 2014): 

Vietnamese Dragon Fruit
HANOI  (VNS) - New Zealand and Viet Nam signed an agreement on the export of Vietnamese dragon fruit in Ha Noi in May. 
New Zealand's Ambassador to Viet Nam Haike Manning and Nguyen Xuan Hong, general director of the Plant Protection Department of Viet Nam's Ministry of Agriculture and Rural Development, signed the Official Assurance Programme.

The programme sets out the procedures and activities to be implemented prior to the export of the cargo to ensure that the fresh dragon fruit exported from Viet Nam to New Zealand meet the import regulations for biosecurity and health requirements.

"I am delighted to announce that Viet Nam is now the first and only country approved for exporting dragon fruit to New Zealand. We don't import dragon fruit from any other country currently. I am sure the imports will start arriving on New Zealand's shores soon so that our consumers can start enjoying this wonderful tropical fruit," Ambassador Manning said. Read more here....

Auditors getting their due; Kroger sues Primus in Jensen cantaloupe listeria outbreak; BarfBlog (June 6, 2014): 

Coral Beach of the Packer writes that in a cross claim filed June 2 in a Colorado state court, the country's second largest retailer names Primus and distributor Frontera Produce Ltd. as defendants in the death of a Colorado man who contracted a Listeria monocytogenes infection after eating cantaloupe from the Holly, Colo. 

"Primus misrepresented the conditions and practices at Jensen Farms ranchlands and packinghouse by giving it a superior rating and high score despite the existence of conditions and practices that should have caused a failure of the facility," according to Kroger's claim.

Primus has 30 days to respond, but the food safety auditing company has maintained its lack of liability in dozens of cases filed by victims and relatives and in a federal case filed by brothers Eric and Ryan Jensen, owners of the bankrupt cantaloupe operation.

The 2011 listeria monocytogenes outbreak traced to the Jensens' cantaloupe resulted in 33 deaths and another 147 illnesses across 28 states, according to the Centers for Disease control and Prevention. Read more here..... is an excellent source of information on food irradiation.

Food Irradiation Update is published by Ronald F.  Eustice and sent to you through the sponsorship of GRAY*STAR, Inc., the manufacturer of the Genesis Irradiator. 
Food irradiation is a cold pasteurization process that will do for meats, produce, and other foods what thermal pasteurization did for milk decades ago.
Ronald F. Eustice, Consultant
Phone: 612.202.1016 





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