Meat Decontamination 69tions, have been suggested for post - chilling
decontamination of carcasses and trimmings.
Specifi cally, post - chilling sequential expo-
sure of beef and pork trimmings to temperate
(25 ° C, 75 – 180 s) or hot (65 or 82 ° C, 15 – 45 s)
water, lactic acid (2% for 15 – 120 s or 5% for
30 s) and hot air (510 ° C, 75 s) reduced total
bacteria and preserved ground products
derived from these trimmings during refrig-
erated storage (Castelo et al. 2001a, b ; Kang
et al. 2001a, b ; Stopforth et al. 2005 ).
Pohlman et al. (2002a, b, c) found that single
or double sequential treatments of beef
trimmings with solutions of chemical anti-
microbials, such as 5% acetic acid, 1%
ozonated water, 0.5% CPC, 200 ppm ClO 2 ,
and 10% TSP, may signifi cantly reduce
Salmonella and E. coli, TCC, and APC,
while maintaining redness and fresh odor of
ground beef produced from the treated trim-
mings during storage under retail display
conditions at 4 ° C. Other antimicrobials,
including low - molecular weight polylactic
acid (2%) and nisin (2%) (Ariyapitipun et al.
2000 ), applied alone or in combination on
beef cubes, have reportedly suppressed
growth of L. monocytogenes during vacuum
storage at 10 ° C.
Post - chilling interventions, applied fol-
lowing pre - chilling treatments, may increase
the total reductions achieved by pre - chilling
interventions. Specifi cally, Castillo et al.
(2001b) found that pre - chilling water and
lactic acid (2%) treatments reduced
Salmonella and E. coli O157:H7 by 3 log 10
CFU/cm^2 , while subsequent post - chilling
application of lactic acid (4%) by spraying
increased total reductions to > 5 log 10 CFU/
cm^2. Likewise, Stopforth et al. (2005) found
that post - chilling application of 5% LA
(55 ° C, 30 s) on beef carcass samples con-
ferred additional reductions to those achieved
by pre - chilling sequential treatments with
warm (55 ° C), hot (82 ° C) water, and 1% SM
(82 ° C), simulating pre - and post - evisceration
of beef carcasses and pre - chilling decontami-
nation interventions, respectively.commercial facility (Bauermeister et al.
2008 ); PAHP mixture was more effective
than 30 ppm chlorinated water.
Nonetheless, chillers may also be sites of
cross - contamination. Studies have shown
that chilling may increase the incidence of
Salmonella on poultry carcasses (Stopforth et
al. 2007 ) as well as E. coli counts on beef
carcasses (Gill and Landers 2003b ). Possible
routes of contamination include the chiller
exit contact surfaces, as well as contact
between carcasses and conveyors (Stopforth
et al. 2007 ; Gill and Landers 2003b ).
Therefore, post - chilling interventions may be
useful for reduction of contamination before
and after fabrication.
Post - Chilling Decontamination
Treatments
Despite the reduction of microbial popula-
tions and pathogen prevalence by decontami-
nation interventions during slaughtering,
dressing, and chilling, surviving microorgan-
isms or additional contamination may be
present on carcasses, primal and sub - primal
cuts, and trimmings (Gill and Bryant 1992 ;
Bacon et al. 2002b ). Thus, post - chilling
decontamination treatments of whole carcass
sides and cuts may be useful in further reduc-
ing microbiological contamination of meat
and preventing pathogen proliferation during
storage of packaged meat. For example, post -
chilling spraying of beef carcass samples
with 4% lactic acid (55 ° C, 30 s) reduced
inoculated Salmonella and E. coli O157:H7
by 1.9 – 2.4 log 10 CFU/cm^2 and decreased their
populations during storage (4 ° C) of ground
meat prepared from treated samples (Castillo
et al. 2001b ). Beef processors in the United
States apply decontamination interventions
of lactic acid and Inspexx 200 ™ or Sanova ®
on carcass sides as they exit the cooler and
enter into fabrication.
Multiple sequential treatments, including
hot water and air, as well as chemical solu-