Meat Decontamination 71O157:H7 and Salmonella was 0.68% and
1.28%, respectively, suggesting implementa-
tion of effective decontamination strategies
(USDA - FSIS 2007 ). In all positive samples,
pathogens were below 3 MPN/cm^2.
Microbial surveys have also been carried
out by individual research groups in slaugh-
tering plants (for steers, heifers, lambs, cows,
and bulls) to evaluate whether and how much
the applied control measures increased the
probabilities of carcasses passing the imposed
performance criteria (Sofos et al. 1999b, c, d ;
Bacon et al. 2000, 2002a, b ; Elder et al. 2000 ;
Duffy et al. 2001 ; Arthur et al. 2004 ). Some
of these studies (Sofos et al. 1999b, c, d )
were carried out in 1995 – 1996, while the
industries were preparing to operate under
HACCP, and thus, could be used to compare
and evaluate the effectiveness of the control
strategies to be applied. The establishments
involved in these surveys used either single
or sequential decontamination interventions.
Pre - evisceration interventions (in the follow-
ing order of application) included: (i) steam -
vacuuming; (ii) carcass - washing with water
(21 – 38 ° C) or organic acids (acetic or lactic
acid 1.6 to 2.6%, 43 – 60 ° C); and, (iii) hot
water (71 – 77 ° C) or steam pasteurization.
Post - evisceration interventions included: (i)
organic acid solution rinsing; (ii) pre - chilling
carcass - washing (fi nal washing); and, (iii)
24 - hour chilling. Reductions in the magni-
tude of 3 – 4 log 10 CFU/cm^2 were obtained for
total bacterial counts, TCC and E. coli start-
ing immediately after hide removal and
before any decontamination until the end of
chilling (Bacon et al. 2000 ). Regarding the
animal type, Salmonella incidence after chill-
ing was higher on cow - bull (0.5 – 4.4%) than
on steer - heifer (0 – 2.2%) carcasses (Sofos et
al. 1999c ). The percentage of samples passing
the performance criteria for E. coli counts
(m < 5 CFU/cm^2 ) increased from 68.3% at
pre - evisceration to 96.2% after fi nal washing
(Sofos et al. 1999b, d ). It was more diffi cult
to meet the performance criteria during the
wet (November through January) than theucts, including broilers, cows, bulls, steers,
and heifers, as well as ground beef, ground
chicken, and ground turkey collected from
large to very small federally inspected U.S.
establishments, showed that the prevalence
of Salmonella was signifi cantly lower after
than before the implementation of HACCP
(Rose et al. 2002 ). The above results also
showed signifi cant compliance with per-
formance criteria for E. coli and standards
for prevalence of Salmonella (USDA - FSIS
1996c; 1998a, b ; Rose et al. 2002 ). The
prerequisites/HACCP verifi cation testing
program for Salmonella in raw meat (cows,
bulls, steers, heifers, hogs) and poultry prod-
ucts in the period 1998 – 2007 showed that the
average percentage of samples from different
product categories, such as carcasses, cuts, or
ground products, meeting the performance
standards for prevalence of Salmonella
exceeded 90% (USDA - FSIS 2008b ).
However, the presence of pathogenic bacte-
ria on the surface of carcasses, even though
of low prevalence, emphasizes the need for
proper refrigeration, handling, and cooking
of meat products before consumption. Testing
of raw ground beef for E. coli O157:H7 from
1994 to 2007 showed an average percentage
of less than 0.5% for positive samples from
federal establishments and retail stores,
and a decreasing trend of E. coli O157:H7
prevalence below 0.20% after 2003, in
samples taken for the U.S. ground beef
testing program (USDA - FSIS 2008a ). In
order to keep the percentage of positive raw
ground beef samples low, FSIS considers it
extremely critical to keep the percent of
positive ratings for beef trimmings low.
Therefore, routine verifi cation sampling of
beef manufacturing trimmings intended for
use in raw ground beef or beef patty products
has also been initiated at the slaughter estab-
lishments that produce such trimmings. The
results of a one - year (December 2005 –
January 2007) study for approximately
1,700 – 1,900 samples of beef trimmings
showed that the prevalence of E. coli