By Michael Hill
Siddharth Bhide — a Rutgers food science graduate student — is about to clean or decontaminate fresh produce without using any water.
He’s using cold plasma. This plasma is a ray of light created by heating up molecules — the sun itself is plasma. All over the country and the world, researchers and professionals are using cold plasma for dentistry, for cancer and wound treatment and to sterilize medical equipment.
Right now, the food industry relies on water and other methods to wash fresh produce.
“That has the potential of cross contamination. So a bacteria can leave one fruit and go and attach to another fruit, and that’s also what we’re studying right now by the way. But this way, there is no possibility of cross contamination from one fruit to the other fruit. And because chlorine also has its own problems — environmentally as well as some other issues from the nutritional point of view,” said Dr. Mukund Karwe, chair of the Rutgers Food Science Department.
Dr. Karwe says Rutgers research shows cold plasma can inactivate the bacteria on the surface, not penetrate the produce and leave the nutrients intact — even after fruits and vegetables have been packaged for sale.
“Something can happen after they’re washed and before they enter the package so cold plasma, there’s a possibility of doing it post packaging so that will prevent, minimize the risk even further,” Dr. Karwe said.
The overall goal is preventing food poisoning or foodborne disease that the Centers for Disease Control and Prevention says makes 48 million Americans sick each year, hospitalizes 128,000 Americans and kills 3,000.
“This could be a major breakthrough in the fresh fruit, fresh produce industry,” said Dr. Karwe.
The founder of Fresh Cut Produce in South Jersey says he has interest in cold plasma.
“Obviously we’re always looking for opportunities that will help us to control the microbes in our products,” said Sam Pipitone Jr., CEO, president and founder of F & S Produce Co., Inc..
“We currently use a variety of methods to try to keep our food clean and pathogen-free but unfortunately with the recalls that you hear about in the world of news, it’s a very difficult thing to do,” said Doug Nicoll, director of technical services and food safety for F & S Produce Co., Inc.
Researchers say so far this technology seems to work well on smooth surface produce like apples, not as well yet on oranges, and certainly not as well on rougher surfaces like cantaloupes.
Bhide’s research aims to pinpoint why because he says spending a lot more time decontaminating rougher-surfaced produce is not the answer.
“The longer the time of the treatment, the better the inactivation. But, you also need to look at industry and this technology out in the market. Treating any produce for five minutes or 10 minutes, that’s kind of impractical,” he said.
No one knows yet how soon food companies will start using cold plasma to kill germs, but with all the other already accepted applications for it, it seems inevitable.