Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chlorine dioxide gas kills dangerous biological contaminants

13.09.2002


The same sanitizing agent used to rid federal office buildings of anthrax – chlorine dioxide gas – can effectively eliminate deadly bacteria from apples and other fruits and vegetables, according to Purdue University researchers.



Scientists at Purdue began experiments using the gas to kill pathogens found on food long before anthrax was detected in mail sent to offices in New York and Washington, D.C., shortly after the terrorist attacks one year ago. The latest university test measured how effectively different potencies of chlorine dioxide (ClO2) gas used over various periods of time could kill Listeria monocytogenes cells on apples.

Results of the study, published in the September issue of Food Microbiology, demonstrated that the vapor was able to eradicate all of the contaminant on the fruit’s skin and significantly reduce the bacteria in the stem cavity and the calyx, said Richard Linton, director of Purdue’s Center for Food Safety Engineering and senior author. The calyx is the apple’s bottom, directly opposite from the stem cavity.


"We see more and more cases of food-borne diseases associated with fruits and vegetables," Linton said. "Some of this is because we encourage people, especially children and the elderly, to eat more and more of these types of foods for added health benefits. Yet these are two of the groups most susceptible to bacteria on food.

"Just 10 to 100 cells of Listeria on a piece of food can cause illness, and it’s possible for 1,000 to 10,000 cells to be on a piece of fruit. We need to develop ways to make food safer; traditional sanitation methods to remove pathogens are not effective enough to meet these new standards."

Although Listeria is relatively rare, it is considered the most deadly of the food-borne pathogens with a 20 percent fatality rate. The Clinton administration issued a "no tolerance" edict for Listeria in processed and ready-to-eat foods, such as hot dogs, and in dairy products. Under the policy, if one organism is found on a piece of food, the whole batch must be discarded and/or recalled from stores, warehouses and consumers’ shelves.

In addition, the FDA requires that sanitizers be effective enough to reduce organisms by at least 100,000 fold for Listeria, E. coli O157:H7, and Salmonella. In this study, Linton and his team achieved this level of Listeria elimination on the apple skin. Even on the stem cavity and calyx, the gas reduced the pathogen to a far greater extent than currently possible with other methods.

Another of the paper’s authors, Purdue food science researcher Yingchan Han, said one reason Listeria was used for the study is because it’s hardy; it can survive in refrigeration and is difficult to inactivate.

"Using the chlorine dioxide gas makes it possible to reduce the bacteria before the apples are cut up or mashed, a significant breakthrough for decontamination processes at small juice-producing companies," Han said. "They often don’t have the pasteurization heating systems necessary to meet USDA requirements for eliminating biological contaminants. These processors produce unpasteurized juice."

The chlorine dioxide process is "extraordinarily" better than other chemical methods of eliminating pathogens on produce, he said.

In the current research, the chlorine dioxide gas, used at a concentration of 4 mg per liter for 30 minutes, lowered the Listeria organisms a minimum of more than 1,000-fold for all three areas of apple tested. On the pulp, the average was more than a 100,000-fold reduction. These results support previous test results when Purdue scientists used the gas to sanitize green peppers.

Linton said the gas is so effective because it’s a strong oxidizing agent.

"Oxidizing agents disrupt the cell membrane, in this case of the bacteria, and this causes the cell to die," he said. "The chlorine dioxide gas is 1,000 times more effective than any other method tried so far for eliminating food-borne pathogens."

He and Han said they don’t believe this process will work well on already cut fruits and vegetables, and not at all for some varieties, such as lettuce, because it would likely affect the color. However, they will be testing the gas on other pathogens, such as Salmonella or E. coli, and on other foods. They also will be determining ways to make the process viable for use by commercial food producers.

The other scientist involved in this study was Jinhua Du.

The U.S. Department of Agriculture funded this research.

Purdue’s Center for Food Safety Engineering includes nearly 90 university scientists collaborating with USDA-Agricultural Research Service scientists to find faster, more exact ways to detect biological and chemical food-borne contaminants and to protect against them.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Sources:Richard Linton, (765) 494-6481, lintonr@foodsci.purdue.edu

Yingchang Han, (765) 494-8267, hany@foodsci.purdue.edu

Ag Communications: (765) 494-2722; Beth Forbes, bforbes@aes.purdue.edu; http://www.agriculture.purdue.edu/AgComm/public/agnews/

Susan A. Steeves | EurekAlert!
Further information:
http://www.cdc.gov/ncidod/eid
http://www.arserrc.gov/www/
http://www.fsis.usda.gov/

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>