The effect of copper on the death rate of Salmonella typhimurium DT104:30 in food substrates acidified with organic acids

Lett Appl Microbiol. 2004;38(1):8-12. doi: 10.1046/j.1472-765x.2003.01147.x.

Abstract

Aims: 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.

Methods and 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.

Significance and impact of the study: This finding could influence policy on levels of copper in pig feed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetic Acid
  • Animal Feed / microbiology
  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Colony Count, Microbial
  • Copper Sulfate / pharmacology*
  • Food Additives / pharmacology*
  • Food Microbiology*
  • Hydrogen-Ion Concentration
  • Lactic Acid
  • Milk / chemistry
  • Milk / microbiology
  • Salmonella typhimurium / drug effects*
  • Salmonella typhimurium / growth & development*

Substances

  • Anti-Bacterial Agents
  • Food Additives
  • Lactic Acid
  • Copper Sulfate
  • Acetic Acid