Effect of x-ray irradiation on reducing the risk of listeriosis in ready-to-eat vacuum-packaged smoked mullet.
Listeria monocytogenes can pose a serious threat in several areas of the nation's food supply including ready-to-eat seafood products. Use of irradiation processing can potentially reduce the risk of listeriosis caused by consumption of ready-to-eat seafood products. This study measured the effect of X-ray irradiation on reducing the population of L. monocytogenes on ready-to-eat, vacuum-packaged smoked mullet. Smoked mullet were inoculated with a five-strain mixture of L. monocytogenes (10(4) CFU/g), vacuum packaged, and irradiated (0, 0.5, 1.0, 1.5, and 2.0 kGy). The packaged fish were then stored at 3 and 10 degrees C for 90 and 17 days, respectively. Radiation doses of 0.5, 1.0, and 1.5 kGy reduced the initial population of L. monocytogenes by 1.1, 1.6, and 2.1 log CFU/g, respectively. The 2.0-kGy dose reduced L. monocytogenes to undetectable levels with no recovery growth at either temperature. Compared to the control, irradiation at 1.5 kGy demonstrated 1.0 and 1.7 log CFU/g less growth at 3 degrees C after 60 days and 10 degrees C after 17 days, respectively. Sensory flavor analysis was conducted to determine if a difference existed between irradiated samples. Panelists indicated that there were no differences among treated and untreated samples. An X-ray dose of 2 kGy effectively eliminated 10(4) CFU/g L. monocytogenes on smoked mullet without changing sensory quality.
Robertson
C B
CB
Department of Food Science, Nutrition, and Health Promotion, Mississippi State University, Box 9805, Mississippi State, Mississippi 39762, USA.
Andrews
L S
LS
Marshall
D L
DL
Coggins
P
P
Schilling
M W
MW
Martin
R E
RE
Collette
R
R
D000818:Animals; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004307:Dose-Response Relationship, Radiation; D005511:Food Handling / Q000379:methods; D005514:Food Irradiation / Q000379:methods*; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D006801:Humans; D008089:Listeria monocytogenes / Q000528:radiation effects*; D008088:Listeriosis / Q000453:epidemiology*; D012307:Risk Factors; D017747:Seafood / Q000382:microbiology / Q000592:standards; D023701:Smegmamorpha; D013649:Taste; D013696:Temperature; D013997:Time Factors; D014618:Vacuum; D014965:X-Rays