December 23, 2011

US research: Blast freezing does not eliminate poultry bacteria

A recently concluded USPOULTRY funded research project at Clemson University discovered that blast (crust) freezing did not result in a significant reduction in bacteria counts compared with fresh and completely frozen treatments.

The purpose of the study was to determine the survival of E. coli and Salmonella on the surface of raw poultry products following blast freezing.

Crust freezing also did not increase shelf life or effect colour and tenderness of raw chicken breast. No differences were found between cold-shocked or non-shocked bacteria on products that were crust or completely frozen.

The project, Blast Surface Freezing to Eliminate Spoilage Bacteria, E. coli and Salmonella on Packaged Meat by Dr. Paul Dawson,  is part of the Association's comprehensive research program encompassing all phases of poultry and egg production and processing.

Research was conducted to determine the survival of Escherichia coli (E. coli) and Salmonella on the surface of raw poultry products following blast (crust) freezing and to determine shelf life of breast meat, with and without skin, following crust freezing.

Salmonella and E. coli bacteria were injected into raw chicken breast, allowed to attach, and then live cells were recovered after exposure to surface (crust) freezing for comparison with bacteria on meat that was only refrigerated or completely frozen. Since bacteria in processing plants are often exposed to low temperatures, both cold-shocked and normal temperature bacteria were injected into samples.