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Consumption of poultry products in the US is a major cause of foodborne microbial illness, with bacterial contamination from Salmonella typhmurium being of especial concern. A new study assesses the effects of selected chemicals of differing concentrations, durations and pressures on bacterial reduction and skin colour of chicken carcasses in a spray testing chamber. The greatest reduction in Salmonella is achieved by different concentrations of trisodium phosphate, sodium bisulfate, cetylpyridinium chloride and lactic acids.

A combined food additive salt solution and low-energy pulsed electrical signals may provide an effective alternate method for reducing Salmonella typhimurium adhering to chicken carcasses during processing. The S. typhimurium populations are reduced by 90% and more, consequent to treatment in 1% NaCl, Na2CO3 or trisodium phosphate solutions for 10 minutes duration. Combined electric and chemical treatments produce greater reduction in bacterial populations than individual conditions used in isolation.

To better understand what physical changes occur in bacteria subjected to low-voltage, low-current electrical stimulation (ES), morphological changes in Salmonella typhimurium killed by ES were examined using electron microscopy. Cells (10 7 CFU/ml) were suspended in 0.015 M NaCl, 0.015 M Na 2 CO 3 , or 0.005 M Na 3 PO 4 ·12H 2 O solutions and pulsed electric signals at 10 mA/cm 2 current, 1 kHz frequency and 50% duty cycle were applied until more than 90% of the cells were dead. In NaCl solutions, cells were swollen before collapsing into amorphous bodies. In Na 2 CO 3 solutions, cells showed irregular surfaces and the cytoplasm became less dense at the centers of the cells. In Na 3 PO 4 solutions, the cytoplasm was scattered into small aggregates within the cell and many fibrils were formed outside. The results of this research suggest that the mechanisms of destruction of S. typhimurium by ES depend on the salt used an electrolyte.