Citric and Lactic Acid Effects on the Growth Inhibition of E. coli and S. typhymurium on Beef during Storage

Preservative and antibacterial effects of citric acid and lactic acid treated beef were studied previously on Escherichia coli O157: H7 and Salmonella typhymurium. This was aimed to investigate the effects of these acids on the total viable count (TVC) of these bacteria. Three diluted concentrations (1.0, 3.0 and 5.0%) of both citric acid and lactic acid were used. A total of 3024 meat samples were collected from cattle slaughtered at Peshawar, Pakistan. Samples were processed and analyzed for TVC of E. coli and S. typhymurium at 0, 48, 144 and 288hrs during 12 days of meat samples refrigeration storage at 4±1 °C. The pH of meat samples were checked and recorded on similar intervals. During 12 days storage, significant reductions (i.e. P 0.05) were found in both E. coli O157: H7 and S. typhymurium growth when exposed to these treatments. Results revealed that levels of citric and lactic acid concentrations effect were maximum for 5.0%, followed by 3.0% and least for 1.0% on E. coli and Salmonella load on beef surfaces. In addition, citric acid was more effective than lactic acid at all concentrations (1.0, 3.0 and 5.0%) in reducing E. coli and Salmonella growth. The citric acid at 5.0% was found significantly effective treatment in reducing E. coli O157: H7 and S. typhymurium population on beef stored samples.