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 A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

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 >>>