Behavior of Listeria monocytogenes in the presence of sodium propionate.
Survival or growth of Listeria monocytogenes in Tryptose Broth supplemented with 0, 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3% sodium propionate was determined when the pH of the medium was 5.0 or 5.6 and incubation was at 4, 13, 21 and 35 degrees C. The pathogen grew in all controls, propionate-free broth, except at 4 degrees C and pH 5.0. At pH 5.6 and 4, 13, 21 and 35 degrees C the bacterium grew in the presence of all propionate concentrations used in this study. The higher concentrations permitted only minimal growth with smallest ultimate populations and longest generation times. Reducing the pH to 5.0 served to minimize growth further at 13, 21 and 35 degrees C than that observed at the same temperatures but at pH 5.6. The extent of growth was directly proportional to the propionate concentrations; at high concentrations, propionate caused a gradual decrease in populations and/or prolonged the lag phase. At 35 degrees C, a concentration of 0.25% did not allow growth, whereas 0.3% caused inactivation of the pathogen after 80 h of incubation. At 4 degrees C and pH 5.0, all concentrations of sodium propionate caused a gradual decrease in populations during the incubation period.
el-Shenawy
M A
MA
Department of Food Science, University of Wisconsin, Madison 53706.
Marth
E H
EH
D000818:Animals; D003470:Culture Media; D005516:Food Microbiology; D005520:Food Preservatives / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development*; D008892:Milk / Q000382:microbiology; D011422:Propionates / Q000494:pharmacology*; D013696:Temperature
D003470:Culture Media; D005520:Food Preservatives; D011422:Propionates; C514135:sodium propionate; C029658:propionic acid