The original commercial Steam Pasteurization
™ System (SPS 400) involved a sealable
moving car by which carcass sides were carried
through the steam chamber at standard line
speeds. A second generation “static chamber”
system (SPS 400-SC) eliminates the mechanical
moving car and has been installed in a large beef
slaughter facility. We collected data to verify
SPS 400-SC’s effectiveness at chamber temperatures
from 185 to 205EF in a batch process
mode (only test carcasses passing through the
unit at variable intervals to facilitate collection of
research samples) and at 190EF with the system
running continuously. Tissue samples were
obtained from different carcass anatomical
locations to evaluate the uniformity of thermal
treatment. Batch-type steam treatment at 185
and 190EF did not consistently produce significant
bacterial reductions on the five anatomical
locations sampled. Batch processing at 195,
200, and 205EF provided increasingly greater
total bacterial reductions, ranging from 1.0 to
2.0 log colony forming units (CFU)/cm2. Under
continuous operation at 190EF, typical of commercial
operation, total bacterial reductions at
the carcass midline averaged 1.6 log CFU/cm2.
The new SPS design is substantially simplified in
terms of moving components and should offer
highly efficient operation and less mechanical
upkeep, extremely important in Hazard Analysis
Critical Control Point (HACCP) programs,
which require assurance of virtually 100%
system operation. The new SPS 400-SC
design will provide beef processors a very
effective and reliable means of assuring that
microbiologically clean carcasses enter the
holding cooler, thus substantially reducing the
risk of pathogenic contamination.