| dc.description.abstract | Salmonella and Escherichia coli O157:H7 (EC) contamination continues to be
one of the major concerns for the microbiological safety of raw poultry and beef
products. Application of more than one decontamination agent as a multi-hurdle
intervention to carcasses in a processing line might produce greater reductions than one
treatment alone due to different modes of action of individual antimicrobials. In this
study, sequential spray applications of e-polylysine (EPL), lauric arginate and acidic
calcium sulfate (ACS) solutions were evaluated against Salmonella Enteritidis (SE) and
Salmonella Typhimurium (ST) on artificially inoculated broiler carcasses and against ST
and EC on beef rounds and ground beef derived from the rounds.
All possible 2-way combinations and individual applications of 20 % ACS
(ACS20), 300 mg/liter EPL (EPL300) and 200 mg/liter LAE (LAE200) were evaluated
using a sterile membrane filter model system. The combinations that provided higher
Salmonella reductions were further evaluated on inoculated chicken carcasses using
either response surface methodology (RSM) or in various concentrations applied in a sequential manner. Sequential spray applications of EPL300 - ACS 30 % (ACS30) or
LAE200-ACS30 produced the highest Salmonella reductions on inoculated chicken
carcasses. In a subsequent experiment, treatment of Salmonella inoculated carcasses
with EPL300-ACS30 or LAE200-ACS30 combinations were found effective for
reducing initial Salmonella counts by 1.5 and 1.8 log CFU/ml, respectively, immediately
after treatment and by 1.2 and 1.8 log CFU/ml, respectively, following 6 days of storage
at 4.4 °C. Evaluation of the resident microflora including aerobic plate counts (APC), E.
coli, coliforms and psychrotrophs on uninoculated chicken carcasses after treatment with
EPL300-ACS30 or LAE200-ACS30 and during storage indicated that these treatments
have the potential to increase the shelf-life of poultry carcasses. Furthermore, application
of warm (55 °C) EPL300-ACS30 or LAE200-ACS30 onto inoculated beef rounds
reduced both ST and EC counts over 6 days of storage at 4.4 °C by 4.5 and 4.3 log
CFU/cm2, respectively. Ground beef manufactured with EPL300-ACS30 or LAE200-
ACS30 treated rounds had lower ST and EC counts initially and stayed lower over 4
days of storage at 4.4 °C when compared to control. | en |
