Elimination of Listeria monocytogenes from Ready-to-Eat Turkey and Cheese Tortilla Wraps Using Ionizing Radiation†

2005 ◽  
Vol 68 (1) ◽  
pp. 164-167 ◽  
Author(s):  
CHRISTOPHER H. SOMMERS ◽  
GLENN BOYD
Keyword(s):  
Listeria Monocytogenes ◽  
Radiation Dose ◽  
Ionizing Radiation ◽  
Wheat Flour ◽  
Radiation Resistance ◽  
Meat Product ◽  
Processed Cheese ◽  
Turkey Meat ◽  
Luncheon Meat ◽  
The Individual

Listeria monocytogenes is a common postprocess contaminant on ready-to-eat foods including premade ready-to-eat sandwiches. One popular type of sandwich product is the tortilla wrap, which contains sliced luncheon meats and cheeses rolled within a flour tortilla. This study determined the radiation resistance of L. monocytogenes surface inoculated onto two types of commercially available wheat flour tortillas, processed cheese slices, and deli turkey meat. The D10-values for L. monocytogenes (the radiation dose required to inactivate 1 log of the pathogen) were 0.27 kGy when inoculated onto two flour tortilla types, 0.28 and 0.30 kGy when inoculated onto two types of sliced processed cheeses, and 0.58 and 0.65 kGy when inoculated onto two types of sliced deli turkey meat. When two types of tortilla wraps were assembled from the individual components and L. monocytogenes was inoculated into the interfaces between the individual components, the D10-values were 0.27 to 0.37 kGy in the tortilla and cheese interfaces, 0.33 to 0.41 kGy in the cheese and turkey interfaces, and 0.25 to 0.33 kGy in the turkey and tortilla interfaces. The ability of ionizing radiation to reduce pathogen levels on the complex tortilla, cheese, and luncheon meat product was limited by the higher radiation resistance of L. monocytogenes when inoculated onto the ready-to-eat turkey-meat component.

Radiation Resistance of Virulence Plasmid-Containing and Plasmid-Less Yersinia enterocolitica†

2002 ◽  
Vol 65 (3) ◽  
pp. 556-559 ◽  
Author(s):  
CHRISTOPHER H. SOMMERS ◽  
JOHN S. NOVAK
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Yersinia Enterocolitica ◽  
Immune Suppression ◽  
Radiation Resistance ◽  
Type Iii Secretion ◽  
Foodborne Pathogen ◽  
Virulence Plasmid ◽  
Type Iii ◽  
Ground Pork

Yersinia enterocolitica, a foodborne pathogen, can be eliminated from meat by ionizing radiation. Y. enterocolitica sometimes contains a 70-kb virulence plasmid that encodes genes for a type III secretion channel and host immune suppression factors. The radiation resistance of virulence plasmid-containing and plasmid-less Y. enterocolitica was determined. Four Y. enterocolitica serotypes containing (i) the large virulence plasmid, and (ii) their plasmid-less derivatives were inoculated into raw ground pork, which was then vacuum packed and irradiated at 4°C to doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. The D10-value, the radiation dose required to reduce the number of viable Y. enterocolitica by 90%, was not dependent on the presence or absence of the virulence plasmid, but it did differ among the four Y. enterocolitica serotypes.

Prevalence of Listeria monocytogenes and Salmonella in Ready-to-Eat Food in Catalonia, Spain

2008 ◽  
Vol 71 (4) ◽  
pp. 855-859 ◽  
Author(s):  
L. CABEDO ◽  
L. PICART i BARROT ◽  
A. TEIXIDÓ i CANELLES
Keyword(s):  
Listeria Monocytogenes ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Meat Product ◽  
Meat Products ◽  
Smoked Salmon ◽  
Cooked Ham ◽  
Fish Product ◽  
Luncheon Meat ◽  
Meat Samples

Listeria monocytogenes and Salmonella are pathogenic bacteria that can contaminate food products during or after processing. Ready-to-eat (RTE) food does not undergo any treatment to ensure its safety before consumption, and therefore risk of foodborne disease must be considered if these pathogens are present in the food. To evaluate the prevalence of these pathogens in RTE food, 140 RTE fish product samples, 501 RTE meat product samples, 462 RTE dairy samples, and 123 RTE dishes and desserts, providing a total of 1,226 samples, were collected from retail stores and food industry and analyzed for the presence of L. monocytogenes. A total of 1,379 samples consisting of 187 RTE fish products and 569 RTE meat products, 484 RTE dairy products, and 139 RTE dishes and desserts were collected and analyzed for the presence of Salmonella. L. monocytogenes was isolated from 20% of frozen Atlantic bonito small pies, 7.9% of smoked salmon samples, 11.1% of the pork luncheon meat samples, 6.2% of frozen chicken croquettes, 16.9% of cured dried sausage samples, 12.5% of cooked ham samples, and 20% of cooked turkey breast samples. L. monocytogenes was also found to be present in 1.3% of fresh salty cheese samples and 15.1% of frozen cannelloni samples. Salmonella was isolated from 1.2% of smoked salmon samples, 1.5% of frozen chicken croquettes, 2% of cooked ham samples, and 11.1% of cured dried sausage samples. Overall, occurrence of these pathogens in RTE foods was similar to that previously reported in the literature.

Fate of Gamma-Irradiated Listeria monocytogenes during Refrigerated Storage on Raw or Cooked Turkey Breast Meat†

1998 ◽  
Vol 61 (8) ◽  
pp. 979-987 ◽  
Author(s):  
DONALD W. THAYER ◽  
GLENN BOYD ◽  
AUGUSTINE KIM ◽  
JAY B. FOX ◽  
HAROLD M. FARRELL
Keyword(s):  
Listeria Monocytogenes ◽  
Radiation Resistance ◽  
Amino Acid Profile ◽  
Breast Meat ◽  
Turkey Meat ◽  
Irradiation Growth ◽  
D Values ◽  
Gamma Irradiated ◽  
Cooked Meat ◽  
Reducing Potential

The radiation resistance and ability of Listeria monocytogenes ATCC 7644, 15313, 43256, and 49594 to multiply on irradiated, air-packed, refrigerated raw or cooked turkey breast meat nuggets (ca. 25 g) and ground turkey breast meat was investigated. Gamma-radiation D values for L. monocytogenes were significantly different on raw and cooked nuggets, 0.56 ± 0.03 kGy and 0.69 ± 0.03 kGy, respectively; but they were not significantly different (P ≤ 0.05) on raw and cooked ground turkey meat. High populations (~109 CFU/g) of L. monocytogenes declined during 14 days of storage at 4°C in both irradiated and nonirradiated samples of raw but not of cooked ground turkey breast meat. A moderate inoculum (~103 CFU/g) did not survive a radiation dose of 3 kGy. The population increased in cooked but not in raw samples of irradiated ground turkey meat stored at either 2 or 7°C for 21 days. The D value changed significantly from 0.70 ± 0.04 to 0.60 ± 0.02 kGy when the product was cooked to an internal temperature of 80°C before irradiation. Growth on either raw or cooked turkey meat did not alter the radiation resistance of L. monocytogenes. Analyses were performed for pH, aw, moisture, and reducing potential of raw and cooked turkey meat and for pH, amino acid profile, thiamine, and riboflavin contents of aqueous extracts of raw and cooked turkey meats without identifying the factor or factors involved in differences in the survival and multiplication of L. monocytogenes on raw and cooked meat.

Radiation (Gamma) Resistance and Postirradiation Growth of Listeria monocytogenes Suspended in Beef Bologna Containing Sodium Diacetate and Potassium Lactate†

2003 ◽  
Vol 66 (11) ◽  
pp. 2051-2056 ◽  
Author(s):  
CHRISTOPHER SOMMERS ◽  
XUETONG FAN ◽  
BRENDAN A. NIEMIRA ◽  
KIMBERLY SOKORAI
Keyword(s):  
Listeria Monocytogenes ◽  
Radiation Dose ◽  
Ionizing Radiation ◽  
Foodborne Pathogen ◽  
Meat Products ◽  
Radiation Doses ◽  
Refrigerated Storage ◽  
Potassium Lactate ◽  
Sodium Diacetate

Listeria monocytogenes, a psychrotrophic foodborne pathogen, is a frequent postprocessing contaminant of ready-to-eat (RTE) meat products, including frankfurters and bologna. Ionizing radiation can eliminate L. monocytogenes from RTE meats. When they are incorporated into fine-emulsion sausages, sodium diacetate (SDA) and potassium lactate (PL) mixtures inhibit the growth of L. monocytogenes. The radiation resistance of L. monocytogenes, and its ability to proliferate during long-term refrigerated storage (9°C), when inoculated into beef bologna that contained 0% SDA–0% PL, 0.07% SDA–1% PL, and 0.15% SDA–2% PL, were determined. The radiation doses required to eliminate 90% of the viable L. monocytogenes cells were 0.56 kGy for bologna containing 0% SDA–0% PL, 0.53 kGy for bologna containing 0.07% SDA–1% PL, and 0.46 kGy for bologna containing 0.15% SDA–2% PL. L. monocytogenes was able to proliferate on bologna containing 0% SDA–0% PL during refrigerated storage, but the onset of proliferation was delayed by the addition of the SDA-PL mixtures. An ionizing radiation dose of 3.0 kGy prevented the proliferation of L. monocytogenes and background microflora in bologna containing 0.07% SDA–1% PL and in bologna containing 0.15% SDA–2% PL over 8 weeks of storage at 9°C. Little effect on lipid oxidation and color of the control bologna, or bologna containing SDA-PL mixtures, was observed upon irradiation at either 1.5 or 3.0 kGy.

Radiation Sensitization and Postirradiation Proliferation of Listeria monocytogenes on Ready-to-Eat Deli Meat in the Presence of Pectin-Nisin Films†

2009 ◽  
Vol 72 (3) ◽  
pp. 644-649 ◽  
Author(s):  
TONY JIN ◽  
LINSHU LIU ◽  
CHRISTOPHER H. SOMMERS ◽  
GLENN BOYD ◽  
HOWARD ZHANG
Keyword(s):  
Listeria Monocytogenes ◽  
Ionizing Radiation ◽  
Meat Products ◽  
Meat Sample ◽  
Turkey Meat ◽  
Film Treatment ◽  
Microbial Analysis ◽  
Radiation Sensitization ◽  
Meat Samples ◽  
Potential Use

In this study, the ability of pectin-nisin films in combination with ionizing radiation to eliminate Listeria monocytogenes and inhibit its postirradiation proliferation was evaluated. Pectin films containing 0.025% nisin were made by extrusion. The surface of a ready-to-eat turkey meat sample was inoculated with L. monocytogenes at 106 CFU/cm2 and covered with a piece of pectin-nisin film. The samples were vacuum packaged and irradiated at 0, 1, and 2 kGy. The treated samples were stored at 10°C and withdrawn at 0, 1, 2, 4, and 8 weeks for microbial analysis. Reductions in L. monocytogenes viability of 1.42, 1.56, 2.85, 3.78, and 5.36 log CFU/cm2 were achieved for the treatments of 1 kGy, pectin-nisin film, 2 kGy, 1 kGy plus pectin-nisin film, and 2 kGy plus pectin-nisin film, respectively. The greatest reduction (5.5 log CFU/cm2) was observed at 1 week for the 2 kGy plus pectin-nisin film treatment, suggesting that nisin was further released from the film to the surface of meat samples. Pectin-nisin films used in this study did not prevent but did significantly slow (P < 0.05) the proliferation of the L. monocytogenes cells that survived irradiation during 8 weeks of storage at 10°C. These data indicate the potential use of pectin-nisin films alone or in combination with ionizing radiation for preventing listeriosis due to postprocessing contamination of ready-to-eat meat products.

DEVELOPMENT OF RELIABILITY PROJECT ESTIMATION PROCEDURE CONSIDERING EFFECTS OF IONIZING RADIATION FOR ELECTRONIC EQUIPMENT

2019 ◽  
pp. 57-63
Author(s):  
M. A. Artyukhova ◽  
S. N. Polesskiy
Keyword(s):  
Ionizing Radiation ◽  
Radiation Resistance ◽  
Power Plants ◽  
Estimation Procedure ◽  
Reliability Estimation ◽  
Electronic Equipment ◽  
Design Stage ◽  
Space Systems ◽  
Reliability Indicators ◽  
Project Estimation

Human activity is often accompanied by exposure of ionizing radiation: the exploitation of space systems and power plants, research using isotopic sources, medicine. The development of electronic equipment is regulated by carrying out activities to ensure the required reliability and radiation resistance. However, the effect of ionizing radiation on reliability indicators is not taken into account properly, or is not taken into account at all, that sometimes leads to the loss of expensive equipment and even to human victims. The article discusses the methodology for carrying out an adequate estimate of the reliability considering the influence of external influencing factors, including ionizing radiation. The timeliness of decisions making to ensure the required reliability indicators is determined by the completeness of the reliability estimation at the design stage. Effort to ensure the reliability and durability of devices after the design stage is not economically viable. The completeness and adequacy of the estimation always depends on the interaction of specialists in different fields: designers, programmers, experts in the field of circuit design, electrical engineering and experts in the field of reliability and radiation resistance.

scholarly journals Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Ning Liu ◽  
Yang Peng ◽  
Xinguang Zhong ◽  
Zheng Ma ◽  
Suiping He ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Response ◽  
Low Dose ◽  
Linear Trend ◽  
Hematological Parameters ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Spline Models ◽  
Cumulative Radiation Dose

Abstract Background Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers. Methods Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship. Results We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (Ptrend = 0.258), the non-linear trend tested was statistically significant (Pnon-linear = 0.007). Overall, there was a correlation between changing platelets and cumulative radiation dose (a change of βa 0.008 × 109/L during biennially after adjusting for gender, age at baseline, service at baseline, occupation, medical level, and smoking habits; 95% confidence interval [CI] = 0.003,0.014 × 109/L). Moreover, we also found positive first and then negative dose-response relationships between cumulative radiation dose and changing platelets by restricted cubic spline models, while there were negative patterns of the baseline service not less than 10 years (− 0.015 × 109/L, 95% CI = − 0.024, − 0.007 × 109/L) and radiation nurses(− 0.033 × 109/L, 95% CI = − 0.049, − 0.016 × 109/L). Conclusion We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.

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