The effect of copper on the death rate of Salmonella typhimurium DT104:30 in food substrates acidified with organic acids.
OBJECTIVE
The objective of this study was to investigate the effect of copper ions on the survival of Salmonella typhimurium DT104:30 in acidified liquid food substrates.


RESULTS
The decimal reduction time (Dvalue) of Salm. typhimurium DT104:30 was determined in acidified liquid pig feed (LPF) and skimmed milk (SM) containing a range of copper concentrations (0-50 ppm). As copper concentration increased, the death rate of Salm. typhimurium DT104:30 increased. In LPF acidified with 150 mmol l-1 lactic acid the presence of 50 ppm copper resulted in a 10-fold increase in the death rate.


CONCLUSIONS
The presence of copper salts in acidic liquid food substrates significantly increases the death rate of Salm. typhimurium DT104:30.


CONCLUSIONS
This finding could influence policy on levels of copper in pig feed.
Beal
J D
JD
School of Biological Sciences, Faculty of Science, University of Plymouth, Newton Abbot, Devon, UK. jbeal@plymouth.ac.uk
Niven
S J
SJ
Campbell
A
A
Brooks
P H
PH
D019342:Acetic Acid; D000821:Animal Feed / Q000382:microbiology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D019327:Copper Sulfate / Q000494:pharmacology*; D005503:Food Additives / Q000494:pharmacology*; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid; D008892:Milk / Q000737:chemistry / Q000382:microbiology; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000254:growth & development*
D000900:Anti-Bacterial Agents; D005503:Food Additives; D019344:Lactic Acid; D019327:Copper Sulfate; D019342:Acetic Acid