Meat Decontamination 65Aqueous ozone solutions have also been
evaluated as decontamination interventions
for meat. Ozone is a GRAS substance for use
in foods in the United States (Sofos and
Smith 1998 ). In general, water containing
0.5% to 0.95% ozone applied for 16 – 36
seconds at 24 – 36 ° C was not more effective
in reducing APC, E. coli O157:H7, and
Salmonella than knife - trimming or washing
with pure water alone (Gorman et al. 1995b ;
Reagan et al. 1996 ; Castillo et al. 2003 ;
Kalchayanand et al. 2008 ). Similarly, hydro-
gen peroxide at levels of 5% has been found
only slightly more effective than water - wash-
ing and TSP (Gorman et al. 1995b ; Cabedo
et al. 1996 ; Reagan et al. 1996 ; Kochevar et
al. 1997b ). The antimicrobial effect of hydro-
gen peroxide is mainly attributed to the for-
mation of radicals that damage fundamental
cellular components, such as nucleic acids,
lipids, and proteins. There have been con-
trasting reports on the effectiveness of per-
oxyacetic acid (PAA) as a decontaminant,
although a commercial PAA - based solution
(Inspexx 200 ™ , Ecolab Company, St. Paul,
MN) has been approved for application on
carcasses in the United States. This product
has demonstrated approximately 1 log 10 CFU/
cm^2 reductions when applied at 200 ppm at
the post - evisceration stage (Gill and Landers
2003a, b ). However, Penney et al. (2007)
observed 3 – 4 log 10 CFU/cm^2 reductions of E.
coli O157:H7 after treatment with 180 ppm
PAA. Conversely, under the conditions tested
by Gill and Badoni (2004) and Ransom et al.
(2003) , 0.02 – 0.04% PAA had little effect on
APC, TCC, and E. coli. In contrast to treat-
ments with hydrogen peroxide and PAA,
application of 1% CPC for 15 seconds at
35 ° C not only reduced APC and inoculated
E. coli O157:H7 and S. Typhimurium by
6 log 10 CFU/cm^2 , but also totally inhibited
their growth during storage of vacuum - pack-
aged beef at 4 ° C (Cutter et al. 2000 ).
Furthermore, two consecutive washings of
cattle hides (for 3 and 1 min) with 1% CPC
decreased prevalence of E. coli O157:H7 onMustapha 2004 ). A mixture of ASC with
0.5% CPC or 0.1% potassium sorbate yielded
1 log 10 CFU/cm^2 additional reductions and
suppressed growth of pathogens during
storage of treated samples at 4 ° C for 14 days
(Lim and Mustapha 2004 ). A commercially
available compound (Sanova ® ) is comprised
of 1200 ppm sodium chlorite and 2% citric
acid. In general, chlorine compounds are rec-
ommended for use in poultry processing in
order to keep contamination low in chilling
water.
TSP is a bactericidal agent approved for
the treatment of beef and poultry carcasses in
the United States. The antimicrobial activity
of TSP applied at 8 – 12% is attributed to its
high pH (11 – 12) and its ability to reduce
attachment of pathogens to carcass surfaces
(Lillard 1994 ; Mendonca et al. 1994 ; Cabedo
et al. 1996 ; Dorsa et al. 1998a, b, c ). The
latter effect may be further enhanced by
combining 5% Tween 80 with 1% TSP for
treatment of poultry skins (Hwang and
Beuchat 1995 ). A patented solution of TSP
(AvGARD TM , Rhone - Poulenc), commonly
applied at 8 – 12% and temperatures from
10 – 60 ° C (15 – 36 s), has been shown to reduce
Salmonella , E. coli O157:H7, L. monocyto-
genes, C. sporogenes , and APC by 1 to
3 log 10 CFU/cm^2 , on chicken, beef, and pork
tissues (Dickson et al. 1994 ; Lillard 1994 ;
Gorman et al. 1995b ; Dorsa et al. 1997a ;
Kochevar et al. 1997b ; Xiong et al. 1998 ;
Dorsa et al. 1998a, b, c ; Cutter and Rivera -
Betancourt 2000 ; Whyte et al. 2001 ). Wang
et al. (1997) also demonstrated that increas-
ing the water temperature from 10 to 60 ° C
and the spraying pressure from 206.8 to
1034.2 kPa may improve the effectiveness of
10% TSP (30 s) in reducing S. Typhimurium
on chicken skin. In conclusion, TSP appears
to be effective in inhibiting bacterial attach-
ment, thereby facilitating removal of bacteria
by washing. It is not used for treatment of
beef, but it may fi nd some application in
poultry processing (Sofos and Smith 1998 ;
Whyte et al. 2001 ).