story to find out more.
In studies of methods to pasteurize liquid foods
such as apple cider without using heat, research leader Howard Zhang (left) and
chemical engineer David Geveke develop and evaluate pulsed electric field and
radio-frequency electric field treatments. Click the image for more
information about it.
Nonthermal Food Processing Heats Up
October 18, 2006
Technologies such as high-pressure
processing, ultraviolet light and irradiation can be faster, cheaper and less
disruptive to food quality than traditional thermal processing for killing
microbes that can contaminate food products, according to scientists with the
Agricultural Research Service (ARS).
Under the guidance of research leader
Zhang, scientists at ARS' Eastern Regional Research Center (ERRC)
in Wyndmoor, Pa., have investigated the effectiveness of these and other
High-pressure processing (HPP) treatment involves applying 80,000 to 130,000
pounds per square inch of pressure to a sample. The researchers found that
applying that extreme pressure for two to five minutes will inactivate the
majority of microorganisms on or in a food source.
While HPP can eliminate close to 100 percent of vegetative microorganisms,
it is not effective at removing microbial spores. In addition, at a cost of 5
to 10 cents per pound, it's too pricey to be practical. Zhang hopes that future
research will change that.
The scientists have also investigated ultraviolet (UV) light and irradiation
to protect food. They used UV processing on an apple cider sample that had been
inoculated with bacteria. The UV treatment compared favorably to heat
pasteurization, reducing the pathogen populations by more than 99 percent
without changing the cider's flavor.
Irradiation exposes food to a low level of ionizing radiation to inactivate
molds, yeasts, parasites, bacteria and other microorganisms that can lead to
food spoilage and illness. Studies show that eating irradiated foods poses no
increased health risk for consumers.
ERRC research findings have enabled federal regulatory agencies to establish
standards to ensure the safety and quality of irradiated products like fruit,
vegetables, juice, meat and meat substitutes.
more about this and other food safety research in the October 2006 issue
of Agricultural Research magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.