Reduction of Numbers of Salmonella typhimurium on Poultry Parts by Repeated Freeze‐Thaw Treatments

Cells of Salmonella typhimurium suspended in 50 ml of 0.1% buffered peptone were subjected to five cycles of rapid or slow freezing and rapid or slow thawing. A five cycle rapid freeze‐rapid thaw process was found to be an effective treatment resulting in 99% reduction in the numbers of S. typhimurium cells. Of the surviving cells after treatment, 75% was sublethally injured. The five cycle rapid freeze‐rapid thaw process was investigated for its effectiveness in reducing numbers of S. typhimurium cells on experimentally inoculated chicken wings. The part of chicken wings consisting of ulna and radius with attached skin and muscle was inoculated with low (16–20 CFU/g) or high (ca 1,100 CFU/g) numbers of S. typhimurium and each wing was subjected to five cycles of the rapid freeze‐rapid thaw process. There was over 90% reduction in the numbers of S. typhimurium cells on the chicken wings after the freeze‐thaw treatment.