Featured Research

from universities, journals, and other organizations

Chlorine Dioxide Gas Kills Dangerous Biological Contaminants

Date:
September 16, 2002
Source:
Purdue University
Summary:
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.

WEST LAFAYETTE, Ind. -- 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.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Chlorine Dioxide Gas Kills Dangerous Biological Contaminants." ScienceDaily. ScienceDaily, 16 September 2002. <www.sciencedaily.com/releases/2002/09/020916063725.htm>.
Purdue University. (2002, September 16). Chlorine Dioxide Gas Kills Dangerous Biological Contaminants. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2002/09/020916063725.htm
Purdue University. "Chlorine Dioxide Gas Kills Dangerous Biological Contaminants." ScienceDaily. www.sciencedaily.com/releases/2002/09/020916063725.htm (accessed July 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Dogs Appear To Become Jealous Of Owners' Attention

Dogs Appear To Become Jealous Of Owners' Attention

Newsy (July 23, 2014) A U.C. San Diego researcher says jealousy isn't just a human trait, and dogs aren't the best at sharing the attention of humans with other dogs. Video provided by Newsy
Powered by NewsLook.com
Professor Creates Site Revealing Where People's Cats Live

Professor Creates Site Revealing Where People's Cats Live

Newsy (July 23, 2014) ​It's called I Know Where Your Cat Lives, and you can keep hitting the "Random Cat" button to find more real cats all over the world. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins