Fresh-Cut Research Projects

April 22, 2010

A full ballroom at the Venetian Hotel in Las Vegas heard about two interesting research projects that could have implications for the fresh-cut produce industry.

Alan Lefcourt with USDA”s Agricultural Research Service presented his team”s work on a laser imaging system that could one day be mounted to a tractor that would drive through a field and identify fecal material on the soil and plants, as well as areas that animal intrusions. The system will need to be interactive, adjustable, allow for false positives, be able to detect one fecal deer pellet and keep a complete visual record.

So far, Lefcourt”s system uses a laser with expansion optics and a gated camera to record the exposure times. The laser system is currently in the lab stage, but the next stage will be to take it out into the field on a cart to see if it works.

While such a system would be expensive, and potentially slow, Lefcourt said there are adjustments. If a company only wanted to look for feces on the soil, a less expensive system could be used. Also, if it were only to be used in low ambient light, then a lower power diode laser could be used. And since the system uses florescence, it could be used to detect other problems, such as water stress and nitrogen stress.

“This will make this much economically viable to do all those things at the same time,” Lefcourt said.

Mark Morgan from Purdue University also presented his work on gaseous chlorine as a kill step in produce. On April 25, a gaseous chlorine system went into production for use in bulk aseptic storage vessels. It”s also being used in storage vessels. But it”s not approved for food contact, so Morgan”s research is looking at ways to commercialize it and find ways to get it approved by USDA and FDA.

In lab tests, gaseous chlorine dioxide effectively reduced pathogens on some fresh produce items. Depending on time and concentration, as much as a 7 log reduction could be reached. In some items, like leafy greens, the concentration needed to kill pathogens damaged the product, so it”s not an effective treatment for all produce. Tomatoes, on the other hand, had effective control at much lower concentrations than other items, likely a result of the skin, Morgan said.

A gaseous chlorine dioxide system is being scaled up to test it in-line in food production, but there are additional measures that had to be taken because it is toxic at low levels.

Morgan said future research on gaseous chlorine dioxide could focus on a system for sanitizing pallets of produce, which would require forcing the gas through the crates like in an ethylene system.

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