Inactivation of Salmonella enterica serovar Enteritidis on shell
eggs by ozone and UV radiation.
Department of Food Science and Technology, The Ohio
State University, Columbus, Ohio 43210, USA.
The presence of Salmonella enterica serovar
Enteritidis in shell eggs has serious public health implications.
Several treatments have been developed to control Salmonella on eggs
with mixed results. Currently, there is a need for time-saving,
economical, and effective egg sanitization treatments. In this study,
shell eggs externally contaminated with Salmonella (8.0 x 10(5) to 4.0 x
10(6) CFU/g of eggshell) were treated with gaseous ozone (O3) at 0 to 15
lb/in2 gauge for 0 to 20 min. In other experiments, contaminated shell
eggs were exposed to UV radiation at 100 to 2,500 microW/cm2 for 0 to 5
min. Treatment combination included exposing contaminated eggs to UV
(1,500 to 2,500 microW/cm2) for 1 min, followed by ozone at 5 lb/in2
gauge for 1 min. Eggs that were (i) noncontaminated and untreated, (ii)
contaminated and untreated, and (iii) contaminated and treated with air
were used as controls. Results indicated that treating shell eggs with
ozone or UV, separately or in combination, significantly (P < 0.05)
reduced Salmonella on shell eggs. For example, contaminated eggs treated
with ozone at 4 to 8 degrees C and 15 lb/in2 gauge for 10 min or with UV
(1,500 to 2,500 microW/cm2) at 22 to 25 degrees C for 5 min produced
5.9- or 4.3-log microbial reductions or more, respectively, when
compared with contaminated untreated controls. Combinations including UV
followed by ozone treatment resulted in synergistic inactivation of
Salmonella by 4.6 log units or more in about 2 min of total treatment
time. Salmonella was effectively inactivated on shell eggs in a short
time and at low temperature with the use of a combination of UV
radiation and ozone.
PMID: 15830660 [PubMed - indexed for MEDLINE]