Thermal inactivation ofClostridium perfringensvegetative cells in ground beef and turkey as affected by sodium pyrophosphate

1998 ◽  
Vol 15 (3) ◽  
pp. 281-287 ◽  
Author(s):  
V.K Juneja ◽  
B.S Marmer
Keyword(s):  
Thermal Inactivation ◽  
Ground Beef ◽  
Sodium Pyrophosphate

scholarly journals Predictive Thermal Inactivation Model for Effects of Temperature, Sodium Lactate, NaCl, and Sodium Pyrophosphate on Salmonella Serotypes in Ground Beef

2003 ◽  
Vol 69 (9) ◽  
pp. 5138-5156 ◽  
Author(s):  
Vijay K. Juneja ◽  
Harry M. Marks ◽  
Tim Mohr
Keyword(s):  
Heat Resistance ◽  
Survival Data ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Sodium Lactate ◽  
Sodium Pyrophosphate ◽  
Relative Reduction ◽  
Survival Curves ◽  
The Times ◽  
The Individual

ABSTRACT Analyses of survival data of a mixture of Salmonella spp. at fixed temperatures between 55°C (131°F) and 71.1°C (160°F) in ground beef matrices containing concentrations of salt between 0 and 4.5%, concentrations of sodium pyrophosphate (SPP) between 0 and 0.5%, and concentrations of sodium lactate (NaL) between 0 and 4.5% indicated that heat resistance of Salmonella increases with increasing levels of SPP and salt, except that, for salt, for larger lethalities close to 6.5, the effect of salt was evident only at low temperatures (<64°C). NaL did not seem to affect the heat resistance of Salmonella as much as the effects induced by the other variables studied. An omnibus model for predicting the lethality for given times and temperatures for ground beef matrices within the range studied was developed that reflects the convex survival curves that were observed. However, the standard errors of the predicted lethalities from this models are large, so consequently, a model, specific for predicting the times needed to obtained a lethality of 6.5 log10, was developed, using estimated results of times derived from the individual survival curves. For the latter model, the coefficient of variation (CV) of predicted times range from about 6 to 25%. For example, at 60°C, when increasing the concentration of salt from 0 to 4.5%, and assuming that the concentration of SPP is 0%, the time to reach a 6.5-log10 relative reduction is predicted to increase from 20 min (CV = 11%) to 48 min (CV = 15%), a 2.4 factor (CV = 19%). At 71.1°C (160°F) the model predicts that more than 0.5 min is needed to achieve a 6.5-log10 relative reduction.

Thermal Inactivation of Escherichia coli O157: H7, Salmonella senftenberg, and Enzymes with Potential as Time-Temperature Indicators in Ground Beef

1997 ◽  
Vol 60 (5) ◽  
pp. 471-475 ◽  
Author(s):  
ALICIA ORTA-RAMIREZ ◽  
JAMES F. PRICE ◽  
YIH-CHIH HSU ◽  
GIRIDARAN J. VEERAMUTHU ◽  
JAMIE S. CHERRY-MERRITT ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Triose Phosphate ◽  
Beef Products ◽  
Z Value ◽  
D Values ◽  
Salmonella Senftenberg

The USDA has established processing schedules for beef products based on the destruction of pathogens. Several enzymes have been suggested as potential indicators of heat processing. However, no relationship between the inactivation rates of these enzymes and those of pathogenic microorganisms has been determined. Our objective was to compare the thermal inactivation of Escherichia coli O157:H7 and Salmonella senftenberg to those of endogenous muscle proteins. Inoculated and noninoculated ground beef samples were heated at four temperatures for predetermined intervals of time in thermal-death-time studies. Bacterial counts were determined and enzymes were assayed for residual activity. The D values for E. coli O157:H7 were 46.10, 6.44, 0.43, and 0.12 min at 53, 58, 63, and 68°C, respectively, with a z value of 5.60°C. The D values for S. senftenberg were 53.00, 15.17, 2.08, and 0.22 min at 53, 58, 63, and 68°C, respectively, with a z value of 6.24°C. Apparent D values at 53, 58, 63, and 68°C were 352.93, 26.31, 5.56, and 3.33 min for acid phosphatase; 6968.64, 543.48, 19.61, and 1.40 min for lactate dehydrogenase; and 3870.97, 2678.59, 769.23, and 42.92 min for peroxidase; with z values of 7.41,3.99, and 7.80°C, respectively. Apparent D values at 53, 58, 63, and 66°C were 325.03, 60.07, 3.07, and 1.34 min for phosphoglycerate mutase; 606.72, 89.86, 4.40, and 1.28 min for glyceraldehyde-3-phosphate dehydrogenase; and 153.06, 20.13, 2.25, and 0.74 min for triose phosphate isomerase; with z values of 5.18, 4.71, and 5.56°C, respectively. The temperature dependence of triose phosphate isomerase was similar to those of both E. coli O157 :H7 and S. senftenberg, suggesting that this enzyme could be used as an endogenous time-temperature indicator in beef products.

Thermal Inactivation D- and z-Values of Multidrug-Resistant and Non–Multidrug-Resistant Salmonella Serotypes and Survival in Ground Beef Exposed to Consumer-Style Cooking

2008 ◽  
Vol 71 (3) ◽  
pp. 509-515 ◽  
Author(s):  
J. D. STOPFORTH ◽  
R. SUHALIM ◽  
B. KOTTAPALLI ◽  
W. E. HILL ◽  
M. SAMADPOUR
Keyword(s):  
Heat Resistance ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Antibiotic Use ◽  
Multidrug Resistant ◽  
Significant Difference ◽  
Salmonella Serotypes ◽  
D Values ◽  
Food Processes ◽  
Best Fit

There has been speculation that multidrug-resistant (MDR) strains are generated by subtherapeutic antibiotic use in food animals and that such strains result in increased resistance to lethality by food processes such as heat and irradiation. The objective of this study was to evaluate the heat resistance of 20 strains, namely an MDR and a non–multidrug-resistant (NMDR) strain of each of 10 Salmonella serotypes isolated from cattle or cattle environments. MDR and NMDR Salmonella serotypes studied included Montevideo, Typhimurium, Anatum, Muenster, Newport, Mbandaka, Dublin, Reading, Agona, and Give. For phase I, stationary-phase cultures of the strains were aliquoted into sterile capillary tubes and immersed in a temperature-controlled water bath at 55, 60, 65, and 70°C for appropriate times. Survivor curves were plotted for each temperature, and a best-fit linear regression was derived for each temperature. D-values (decimal reduction times) and z-values (changes in temperature required to change the D-values) were calculated for each strain. Although there was no overall significant difference in the heat resistance of MDR and NMDR serotypes, NMDR serotypes generally appeared to have slightly higher heat resistance than NMDR serotypes, especially at 55 and 60°C. The highest relative heat resistance (highest z-values) was exhibited by Salmonella Anatum. Notably, the relative heat resistance of NMDR Salmonella Agona was similar to that of NMDR Salmonella Anatum and had the highest D-values at all four temperatures. For phase II, three serotypes (regardless of resistance profile) with the highest relative heat resistance and their drug-resistant counterparts were selected for thermal inactivation in ground beef patties cooked to endpoint temperatures. Salmonella Agona was able to survive in ground beef cooked to an internal temperature of 71°C. Results of these studies suggest drug resistance does not affect the heat resistance of Salmonella and that serotype or strain is an important consideration in risk assessment of the pathogen with regard to survival at cooking temperatures.

A Predictive Model To Determine the Effects of Temperature, Sodium Pyrophosphate, and Sodium Chloride on Thermal Inactivation of Starved Listeria monocytogenes in Pork Slurry

2003 ◽  
Vol 66 (7) ◽  
pp. 1216-1221 ◽  
Author(s):  
M. A. LIHONO ◽  
A. F. MENDONCA ◽  
J. S. DICKSON ◽  
P. M. DIXON
Keyword(s):  
Listeria Monocytogenes ◽  
Predictive Model ◽  
Thermal Inactivation ◽  
Heating Temperature ◽  
Sodium Pyrophosphate ◽  
Effect Of Temperature ◽  
Destructive Effect ◽  
Processed Meats ◽  
Natural Logarithm ◽  
D Values

The effects and interactions of 27 combinations of heating temperature (57.5 to 62.5°C), sodium pyrophosphate (SPP) level (0 to 0.5%, wt/vol), and salt (NaCl) level (0 to 6%, wt/vol) on the thermal inactivation of starved Listeria monocytogenes ATCC 19116 in pork slurry were investigated. A split-split plot experimental design was used to compare all 27 combinations. L. monocytogenes survivors were enumerated on tryptic soy agar supplemented with 0.6% yeast extract. The natural logarithm (loge) of the means of decimal reduction times (D-values) were modeled as a function of temperature, SPP level, and NaCl level. Increasing concentrations of SPP or NaCl protected starved L. monocytogenes from the destructive effect of heat. For example, D-values for the pathogen at 57.5°C in pork slurry with 0, 3, and 6% NaCl were 2.79, 7.75, and 14.59 min, respectively. All three variables interacted to affect the thermal inactivation of L. monocytogenes. A mathematical model describing the combined effect of temperature, SPP level, and NaCl level on the thermal inactivation of starved L. monocytogenes was developed. There was strong correlation (R2 = 0.97) between loge D-values predicted by the model and those observed experimentally. The model can predict D-values for any combination of variables that falls within the range of those tested. This predictive model can be used to assist food processors in designing thermal processes that include an adequate margin of safety for the control of L. monocytogenes in processed meats.

scholarly journals Thermal inactivation and injury of Moraxella-Acinetobacter cells in ground beef.

1980 ◽  
Vol 39 (1) ◽  
pp. 159-164 ◽  
Author(s):  
R Firstenberg-Eden ◽  
D B Rowley ◽  
E Shattuck
Keyword(s):  
Thermal Inactivation ◽  
Ground Beef

A New Kinetic Model for Thermal Inactivation of Microorganisms: Development and Validation Using Escherichia coli O157:H7 as a Test Organism†

2001 ◽  
Vol 64 (12) ◽  
pp. 2078-2082 ◽  
Author(s):  
LIHAN HUANG ◽  
VIJAY K. JUNEJA
Keyword(s):  
Escherichia Coli ◽  
Kinetic Model ◽  
Thermal Inactivation ◽  
Test Organism ◽  
Nonlinear Behavior ◽  
Ground Beef ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
First Order ◽  
Test Microorganism

A new kinetic model has been proposed to simulate the nonlinear behavior of survivor curves frequently observed in thermal inactivation of microorganisms. This model incorporates a time component into the first-order inactivation kinetics and is capable of describing the linear, convex, and concave survivor curves. The model was validated using Escherichia coli O157:H7 as a test microorganism. Ground beef (93% lean) samples inoculated to 107 to 108 CFU/g of meat were subjected to immersion heating at 55, 57.5, 60, 62.5, and 65°C, respectively, in a water bath. All the survivor curves in this study showed upward concavity. Linear and nonlinear regressions were used to fit the survivor curves to the linear first-order inactivation kinetics and the proposed model. Analyses showed that the new kinetic model provides a much better estimate of the thermal inactivation behavior of E. coli O157:H7 in ground beef.

Thermal Inactivation of Escherichia coli O157:H7 Isolated from Ground Beef and Bovine Feces, and Suitability of Media for Enumeration

1998 ◽  
Vol 61 (3) ◽  
pp. 285-289 ◽  
Author(s):  
M. ROCELLE S. CLAVERO ◽  
LARRY R. BEUCHAT ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Treatment Temperature ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Polyethylene Bags ◽  
D Values ◽  
Bovine Feces

Rates of thermal inactivation of five strains of Escherichia coli O157:H7 isolated from ground beef implicated in outbreaks of hemorrhagic colitis and five strains isolated from bovine feces were determined. Ground beef (22% fat, 10 g), inoculated with individual test strains at populations ranging from 6.85 to 7.40 log10 CFU g−1 of beef, was formed into patties (0.3 cm thick and 8.0 cm in diameter) and sealed in polyethylene bags. For each strain and treatment temperature (54.4, 58.9, 62.8, 65.6, or 68.3°C), 6 bags were simultaneously immersed into a recirculating water bath. Viable cells in patties heated for various lengths of time were enumerated by plating diluted samples on sorbitol MacConkey agar supplemented with 4-methylumbelliferyl-β-d-glucuronide (MSMA) and modified eosin methylene blue (MEMB) agar. Regardless of strain or treatment temperature, higher numbers of E. coli O157:H7 cells were generally recovered on MEMB agar than on MSMA, indicating the inferiority of MSMA as a recovery medium for quantitative determination of E. coli O157:H7 cells in heat-processed ground beef. Significantly (P ≤ 0.05) higher D values when enumeration was done using MEMB agar compared with MSMA. Mean D values for combined strain data at 54.4, 58.9, 62.8, and 65.6°C from cultures on MEMB agar were 123.90, 6.47, 0.62, and 0.20 min, respectively, whereas D values of 25.5, 5.21, 0.57, and 0.18 min were obtained at the same temperatures from cultures on MSMA. Results suggest that cooking ground beef patties to an internal temperature of 68.3°C for 40 s will inactivate at least 99.99% of E. coli O157:H7 cells; z values of 4.0 and 5.1°C were calculated from mean D values obtained from MEMB agar and MSMA, respectively, as recovery media. Differences in D values and z values existed among strains but rates of thermal inactivation do not appear to be correlated with the sources of the isolates.

Effects of Salt, Sodium Pyrophosphate, and Sodium Lactate on the Probability of Growth of Escherichia coli O157:H7 in Ground Beef †

2011 ◽  
Vol 74 (4) ◽  
pp. 622-626 ◽  
Author(s):  
CHENG-AN HWANG ◽  
VIJAY JUNEJA
Keyword(s):  
Escherichia Coli ◽  
Logistic Regression ◽  
Probability Model ◽  
Ground Beef ◽  
Sodium Lactate ◽  
Growth Behavior ◽  
Sodium Pyrophosphate ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Beef Products

Ground beef products are susceptible to contamination with Escherichia coli O157:H7. The objective of this study was to examine the effect of salt, sodium pyrophosphate (SPP), and sodium lactate on the probability of growth of E. coli O157:H7 in ground beef under a temperature abuse condition. Ground beef containing 0 to 2.25% salt, 0 to 0.5% SPP, and 0 to 3% lactate was inoculated with a four-strain mixture of E. coli O157:H7, vacuum packaged, and stored at 10°C for 15 days. A total of 25 combinations of the three additives, each with 20 samples, were tested. A logistic regression was used to model the probability of growth of E. coli O157:H7 (with a 1.0-log CFU/g increase during storage) as a function of salt, SPP, and lactate. The resultant probability model indicated that lactate at higher concentrations decreased the probability of growth of E. coli O157:H7 in ground beef, and the effect was more pronounced at higher salt concentrations. At salt concentrations below 1.3%, the increase of SPP concentration marginally increased the growth probabilities of E. coli O157:H7. The model illustrated the effect of salt, SPP, and lactate on the growth probabilities and growth or no-growth behavior of E. coli O157:H7 in ground beef and can be used to improve the microbial food safety of ground beef products.

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