Pathogen-combatting ultrasound wash system could provide organic alternative - developer

By Mark Astley

- Last updated on GMT

Related tags: Food safety, Disinfectant, Chlorine, Hydrogen peroxide

The use of high powered ultrasound could help combat pathogens such as E.coli O157:H7 on salad products.
The use of high powered ultrasound could help combat pathogens such as E.coli O157:H7 on salad products.
‘Organic’ processors could be set for a “significant improvement” in the protection of produce against pathogens through the development of new wash system practices using ultrasound.

California-based Earthbound Farms, which produces organic salad products including spinach, is working alongside researchers from the Chicago-based Institute of Food Safety and Health (IFSH) to develop an organic-friendly wash system to combat the presence of foodborne pathogens.

The IFSH, a department at the Illinois Institute of Technology, is currently conducting pilot tests using treatments including high powered ultrasound (HPU) and peracetic acid-based and citrus-based sanitisers – which are approved for use in organic processes.

HPU works to combat pathogens such as E.coli O157:H7 by creating tiny bubbles. When these bubbles burst on the leaf’s surface, they help dislodge and blast away any pathogens – boosting the effectiveness of the sanitiser in use.

The use of HPU is yet to be implemented at Earthbound Farms, although they hope to adapt the practice as part of its “multi-hurdle”​ food safety approach.

Organic alternative

“We’re hoping to see a significant improvement in the effectiveness of the wash system with the sanitizer plus HPU over simply the sanitizer. We’re testing the HPU in the wash system along with peracetic acid-based and citrus-based sanitizers, both approved for use in organic production,”​ saidEarthbound Farms senior vice president of operation and organic integrity Will Daniels.

The company was forced to take steps to find an alternative to the industry-standard use of chlorine-based washes.

The pathogen-killing additive is not an ideal organic option for processors as regulations demand that residual chlorine remains low.

“There are a few other wash additives out there, but we haven’t seen any data around how effective they are and some aren’t approved for use in organic [processing]. We are still using chlorine, within the organic regulation where residual chlorine is at below 4 parts per million.”

“The HPU is used in the wash together with the sanitizer. We are exploring various sanitizers to see which, if any, performs best. The sanitizers we’re testing are citrus-based and peracetic acid-based, both of which are approved for use in organic production,”​ Daniels added.

“Multi-hurdle” approach

Despite their excitement over the potential implementation of the HPU method, Daniels its implementation would be just one step in ensuring the safety of salad products entering the market.

“But whether organic or conventional, there’s no proven kill step available for fresh-cut salads and other fresh items that are eaten raw,”​ he said.

The company’s “multi-hurdle”​ food safety approach begins in the field and runs through to its processing facility, followed by two rounds of pathogen testing.

“Even if this HPU is incredibly effective, it won’t be a kill step and we’ll still need to have our multi-hurdle approach in place and the HPU will simply be another, we hope higher, hurdle,”​ Daniels concluded.

Related topics: Food Safety & Quality

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