70 Chapter 3
al. 2001b ; Kang et al. 2001b ). However,
post - chilling interventions that may change
the properties of the product require change
in the labeling requirements and the product
may have to be presented with a name more
complex than “ meat, ” unless the treatments
do not cause substantial changes in meat
properties and thus can be designated as a
“ processing aid. ”Overview of Practical
Improvements Achieved by
Decontamination
The Pathogen Reduction fi nal rule (USDA -
FSIS 1996c ) established microbial testing
for meat plants to assess the effectiveness of
the control measures undertaken to prevent
and reduce contamination of carcasses with
fecal material, hair, ingesta, and associated
bacteria. The established criteria for E. coli
and Salmonella were based on national
baseline studies (1992 – 1993) that had col-
lected data from various meat plants (USDA -
FSIS 1994, 1996b ). The adoption of HACCP
principles (USDA - FSIS 1996c ) and associ-
ated critical control points applied as decon-
tamination interventions constitute important
measures for control of carcass contamina-
tion. Following implementation of decon-
tamination strategies in the U.S. beef plants,
microbial testing of carcasses demonstrated
signifi cant improvements in the hygiene of
the slaughtering process. Specifi cally, FSIS
performed a national baseline data collection
program (1997 – 1998) for cattle and swine
carcasses from approximately 1,400 and
1,250 establishments, respectively (USDA -
FSIS 1998a, b ). Prevalence of E. coli and
Salmonella in 1,881 cattle samples was
16.6% and 1.2%, respectively, and 44.1%
and 6.9% in 2,127 swine samples. Of the
samples that were positive for E. coli , 98.9%
of cattle and 91.5% of swine samples had
E. coli between 0 – 10 CFU/cm^2. Furthermore,
a three - year survey (1998 – 2000) of 98,204
samples of various meat and poultry prod-In general, lower water and acid spray
temperatures, as well as shorter exposure
durations compared with pre - chilling inter-
ventions, are recommended in order to avoid
any negative impact on color and odor of cuts
or trimmings (Castelo et al. 2001a ; Kang et
al. 2001a ; Kotula and Thelappurate 1994 ;
Table 3.1 ). Some discoloration may occur on
the surface (to a 2 – 3 mm depth) of trimmings
subjected to multiple decontamination treat-
ments, especially in those including heat and
acid. The discoloration of meat cuts by hot -
water treatment depends on the quality of
meat (normal, dark - fi rm - dry, or pale soft
exudative), the type of tissue (i.e., muscle vs.
fat, or pork vs. beef), and the rigor (i.e. pre -
vs. post - rigor) state (Gill and Badoni 1997 ).
However, the grinding process “ dilutes ” the
surface color, and the resulting product has
color similar to that of products from
untreated trimmings (Kang et al. 2001b ). The
decontamination treatments are more effec-
tive on fat than on lean beef trimmings
because the fat tissue allows higher microbial
reductions (Castelo et al. 2001a, b ), whereas
its color is more stable than that of the lean
tissue (Kang et al., 2001a ). The decision as
to the intensity of post - chilling hot water
treatments is also dependent on the com-
mercial use of the product. For example,
in case of frozen patties destined for restau-
rants, discoloration by hot water is of limited
commercial importance. Conversely, discol-
oration may be important for the acceptabil-
ity of the product by consumers. In this
respect, treatment of beef cuts (manufactur-
ing beef) with hot water (85 ° C, 45 s) reduced
APC by 2 log 10 CFU/cm^2 without any detect-
able effect on the color and fl avor of frozen
beef patties produced from the treated meat
(Gill et al. 2001 ).
Overall, application of decontamination
treatments on trimmings may contribute to
immediate microbial reductions and residual
antimicrobial effects during aerobic storage
or storage of trimming in vacuum sealed
packages (Castelo et al. 2001a, b ; Castillo et