Microstructural factors controlling the survival of food-borne pathogens in porous media.
The survival of Salmonella typhimurium LT2, Escherichia coli K-12 and Pseudomonas putida in several model porous media poised at a water activity of 0.94 is shown to depend critically on the microstructure of the particulate matrix and the microscopic water distribution. The porous media were made by randomly dispersing a liquid inoculum containing ca. 10(7) cells/ml throughout the pores and interparticle spaces of packed beds of silica particles and Sephadex microspheres. The purely "microstructural stress" effects were isolated by comparison with a homogeneous liquid growth medium having the same water activity. The possibility of exploiting similar microstructural stress effects in food preservation is discussed.
Hills
B P
BP
Institute of Food Research, Norwich Research Park, Colney, UK. brian.hills@bbsrc.ac.uk
Arnould
L
L
Bossu
C
C
Ridge
Y P
YP
D015169:Colony Count, Microbial; D003470:Culture Media; D004926:Escherichia coli / Q000254:growth & development*; D005516:Food Microbiology; D008863:Microspheres; D010316:Particle Size; D016958:Pseudomonas putida / Q000254:growth & development*; D012486:Salmonella typhimurium / Q000254:growth & development*; D013997:Time Factors; D014867:Water
D003470:Culture Media; D014867:Water