Food Scientist Uses High Pressure to Keep Food Safe -- for a Long, Long Time

October 26, 2009

Editor: For a high-res version of the attached photo, contact Martha Filipic at filipic.3@cfaes.osu.edu.

COLUMBUS, Ohio -- Ohio State University food science researcher V.M. "Bala" Balasubramaniam isn't feeling pressure to perform. He's using pressure.

The associate professor of food science and technology studies how high-pressure food processing can be used and refined to preserve low-acid foods, allowing them to stay fresh for extensive periods while inactivating the bacteria and other pathogens that would otherwise make them unsafe.

Balasubramaniam, who also has appointments with the Ohio Agricultural Research and Development Center and Ohio State University Extension, and his research associate Jeremy Somerville just published an article on their work, "Pressure-Assisted Thermal Sterilization (PATS) of Low-Acid, Shelf-Stable Foods," in the current issue of Resource, a publication of the American Society of Agricultural and Biological Engineers. Balasubramaniam will also speak on the topic at a food science seminar at noon on Tuesday, Nov. 3, at Ohio State's Parker Food Science and Technology Building, 2015 Fyffe Court in Columbus.

"Most of the traditional products available in the market today are heat-processed," Balasubramaniam said. "Although heat processing, or thermal processing, is one of the safest technologies available today, heat also destroys many nutrients and the quality of the food material."

Subjecting foods to high pressure -- from 72,500 to as high as 130,000 pounds per square inch -- can help foods retain fresh qualities while extensively extending their shelf life. Combining the process with heat offers even more benefits. For example, fresh vegetables -- carrots, cauliflower, green beans -- vacuum-packaged in plastic and subjected to pressure at 87,000 pounds per square inch and heated to 221 degrees Fahrenheit could stay safe and fresh at room temperature for up to two to three years, Balasubramaniam said.

"What we are looking at now is the next generation of high pressure processing -- subjecting low-acid foods to both pressure and heat, to sterilize them so they can be shelf-stable," he said.

Balasubramaniam is focusing his research on determining the optimal pressure and temperature to use on different products so they retain the most nutrients and the freshest flavor and texture possible.

Balasubramaniam's laboratory is also working with the laboratory of a colleague, microbiologist and food science professor Ahmed Yousef, to determine combined pressure-heat resistance of a variety of Clostridium and Bacillus bacterial spores and to identify safe processing conditions for preserving low-acid foods -- the type of foods consumers normally see in the canned goods aisle at the grocery store.

"Today's consumer is interested in minimally processed foods with minimal preservatives," Balasubramaniam said. This new technology could offer just that.

"According to some industry experts, high pressure is probably one of the best innovations in food processing in the last 50 years," he said. "We are excited that Ohio State is part of the leading edge of research in this area."

Food processors interested in more information about high-pressure technology can review a fact sheet, "High Pressure Processing," available online at http://ohioline.osu.edu/fse-fact/0001.html.

Author(s): 
Martha Filipic
Source(s): 
V.M. "Bala" Balasubramaniam