Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fuzz-Free Strawberries Forecast with New Food Safety Treatment

23.11.2004


Open up a pint of strawberries from the grocery store, and more often than not you’ll find a fuzzy berry or two in the mix. A blast of chlorine dioxide gas, however, promises to not only keep those berries fuzz-free, but also to kill off harmful bacteria living on their surface more efficiently than methods currently used by the food industry, say Purdue University researchers.



"Strawberries are tricky," said Rich Linton, professor of food science and one of the leaders of the current study on decontaminating strawberries. "They’re notoriously difficult to clean, and their surface composition actually encourages bugs to grow."

Those bugs can include potentially lethal bacteria, such as E. coli, as well as viruses including hepatitis A, which caused an outbreak linked to frozen strawberries in 1996. "The issue with strawberries is that they’re easily contaminated," Linton said. "They’re grown in close association with soil, where they may pick up pathogens such as E. coil from manure-based fertilizers, and they’re hand-picked, providing another avenue for contamination."


Linton and his colleagues at Purdue’s Center for Food Safety Engineering, who already have demonstrated the efficacy of using chlorine dioxide gas to kill pathogens on the surface of apples and green peppers, have shown the treatment also removes significantly higher levels of pathogens than the current industry-standard chlorinated water rinse.

Linton’s study, published in the current issue of the Journal of Food Protection, compares two different chlorine dioxide treatments, called "batch processing" and "continuous processing." Both treatments provide greater than a 5-log, or 99.999 percent, reduction in the numbers of E. coli and Listeria monocytogenes on strawberry surfaces.

Food safety experts assess decontamination efficiency with a measurement called "log reduction," which indicates how much contamination can be reduced after a decontamination treatment. A log, or logarithm, is a power of ten; thus a 1-log reduction is a 90 percent reduction; a 2-log reduction is a 99 percent reduction, and a 5-log reduction is a 99.999 percent reduction.

While current methods for removing pathogens on strawberries yield about a 2.5 log reduction in bacteria levels, the Food and Drug Administration has stated produce treatments should achieve a 5-log reduction in pathogens.

Not only does Linton’s treatment significantly reduce the number of potentially harmful pathogens growing on strawberries, it also extends their shelf life without sacrificing quality attributes such as color and taste. "The berries last a lot longer after this treatment-in fact, we’ve had strawberries in the refrigerator for more than six weeks with no mold growth," Linton said. "If this process can give consumers even one or two more days before the strawberries they buy get fuzzy, that’s huge. Think about it - how many strawberries do you have to throw away in a pint? If we could reduce that number, it would be a great advantage for consumers and the industry."

The two methods Linton used differ in the way the berries are exposed to the chlorine dioxide. In a batch system, the strawberries are placed in a sealed container, and a set amount of chlorine dioxide gas is applied once and then allowed to remain in the chamber for a period of time. Continuous treatment involves constant delivery of gas into the chamber over time.

Batch treatment required higher concentrations of chlorine dioxide treatment for longer amounts of time than continuous treatment, but both methods achieved more than a 5-log reduction in pathogens, Linton said. He found that either 30 minutes of batch treatment, or 10 minutes of continuous treatment, produced effective levels of decontamination.

Linton’s team currently has funding through the United States Department of Agriculture to scale up this technology and further develop it for use by the food industry. "We see this technology as a potential intervention for security applied to our food system," Linton said. "It may be possible to develop this technology so that we can begin decontaminating produce while it’s in transit. "Much of our produce comes from other countries where we may have less control over sanitary practices in the field. If we could use technology like this to seal up produce and treat it as it travels from point A to point B, it’s a great application for protection of our nation’s food supply."

Also participating in this research were Yingchan Han, post-doctoral research associate; Travis Selby and Krista Schultze, graduate students in the Department of Food Science; and Phil Nelson, professor of food science. The U.S. Department of Agriculture Cooperative State esearch and Extension Service and the Food and Drug Administration provided funding for this work.

| newswise
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>