Dry foods such as peanut butter, spices, or flours are generally considered safe from bacterial contamination because a lack of water does not provide a good environment for most microorganisms to grow.
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However, under these conditions Salmonella, a microorganism that can cause severe intestinal illness, becomes more tolerant to thermal treatments in dry condition, which makes contamination of these foods particularly problematic and concerning from a public health perspective. Thermal treatments, such as pasteurization, are used to heat food to kill disease-causing microorganisms and extend their shelf life.
A new study “iTRAQ-based Global Proteomic Analysis of Salmonella enterica serovar Typhimurium in Response to Desiccation, Low aw, and Thermal Treatment” by Ryan Fink, assistant professor, to be published in the Aug. 31 issue of Applied and Environmental Microbiology seeks to discover what cross-protection phenomenon results in Salmonella’s ability to become more tolerant to thermal treatments in dry environments.
The study was performed in collaboration with the Department of Food Science and Nutrition at the University of Minnesota. Fink and his team investigated the changes in the proteins profiles of Salmonella enterica serovar Typhimurium during exposure to dry conditions and thermal treatment using a new molecular technique called iTRAQ. The research team discovered that a dry condition is fundamental to the physiological shift that allows Salmonella to survive high temperatures.
Fink is an associate professor of biology at St. Cloud State where he also conducts research on Salmonella as a foodborne pathogen. He holds a Ph.D. from the University of Milan, Italy, where he worked on a research project focused on the molecular and quantitative genetics of corn.
He has been researching Salmonella for more than a decade having worked on microbiological projects at North Carolina State University, the University of Miami and the University of Minnesota.
