Scientists Test Method for Sanitizing Leafy
By Rosalie Marion
July 7, 2008
Agricultural Research Service (ARS) scientists are studying new sanitizing
methods to enhance the safety of leafy greenstechnology that may result
in safer salads. That's good news for health-conscious consumers. Today, sales
of fresh cut lettuce and leafy greens have reached $3 billion annually,
according to industry experts, and the demand is increasing.
Luo, with the ARS Produce Quality and Safety Laboratory (PQSL)
in Beltsville, Md., first focused on reformulating a new sanitizer that works
better than chlorine as a wash-solution ingredient. Chlorine solutions have
been used by the food industry to help control microbes on fresh-cut greens,
such as lettuce, but chlorine doesn't eliminate all the organisms that can be
Luo has been collaborating with colleagues at the
University of Illinois to test combining the
use of several sanitizers, including the new formulation, with ultrasound as a
means to enhance the efficiency of sanitization prior to bagging. They
conducted a study to determine the effects of selected sanitizer ingredients,
with or without ultrasound, on the reduction of Escherichia coli
populations on spinach.
The highest E. coli reduction was 4.5 logs--meaning the bacteria
decreased from about 300,000 colony-forming units to less than 10. This
reduction was achieved through combining the newly formulated wash solution
treatment with ultrasound treatment.
The combination of a new sanitizer with ultrasound can potentially be used
to enhance the microbial safety of leafy green produce before the bagging
process, according to Luo.
more about this research in the July 2008 issue of Agricultural Research
ARS is a scientific agency of the U.S.
Department of Agriculture.