scholarly journals Thermal Inactivation Kinetics of Human Norovirus Surrogates and Hepatitis A Virus in Turkey Deli Meat

2015 ◽  
Vol 81 (14) ◽  
pp. 4850-4859 ◽  
Author(s):  
Hayriye Bozkurt ◽  
Doris H. D'Souza ◽  
P. Michael Davidson
Keyword(s):  
Hepatitis A ◽  
Thermal Inactivation ◽  
Hepatitis A Virus ◽  
Weibull Model ◽  
Activation Energies ◽  
Inactivation Kinetics ◽  
Order Model ◽  
Decimal Reduction Time ◽  
First Order ◽  
Kinetics Of

ABSTRACTHuman noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare first-order and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. TheD(decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1 ± 0.0 to 9.9 ± 3.9 min for FCV-F9, 0.2 ± 0.0 to 21.0 ± 0.8 min for MNV-1, and 1.0 ± 0.1 to 42.0 ± 5.6 min for HAV. Using the Weibull model, thetD = 1(time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1 ± 0.0 to 11.9 ± 5.1 min, from 0.3 ± 0.1 to 17.8 ± 1.8 min, and from 0.6 ± 0.3 to 25.9 ± 3.7 min, respectively. Thez(thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3 ± 2.1°C, 11.0 ± 1.6°C, and 13.4 ± 2.6°C, respectively, using the Weibull model. Thezvalues using the first-order model were 11.9 ± 1.0°C, 10.9 ± 1.3°C, and 12.8 ± 1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214 ± 28, 242 ± 36, and 154 ± 19 kJ/mole, respectively, while the calculated activation energies for the first-order model were 181 ± 16, 196 ± 5, and 167 ± 9 kJ/mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks.

Thermal Inactivation Kinetics of Sporolactobacillus nakayamae Spores, a Spoilage Bacterium Isolated from a Model Mashed Potato–Scallion Mixture

2016 ◽  
Vol 79 (9) ◽  
pp. 1482-1489
Author(s):  
HAYRIYE BOZKURT ◽  
JAIRUS R. D. DAVID ◽  
RYAN J. TALLEY ◽  
D. SCOTT LINEBACK ◽  
P. MICHAEL DAVIDSON
Keyword(s):  
Heat Resistance ◽  
Thermal Inactivation ◽  
Weibull Model ◽  
Inactivation Kinetics ◽  
Order Model ◽  
First Order ◽  
Different Temperatures ◽  
Spoilage Bacterium ◽  
D Values ◽  
Kinetics Of

ABSTRACT Sporolactobacillus species have been occasionally isolated from spoiled foods and environmental sources. Thus, food processors should be aware of their potential presence and characteristics. In this study, the heat resistance and influence of the growth and recovery media on apparent heat resistance of Sporolactobacillus nakayamae spores were studied and described mathematically. For each medium, survivor curves and thermal death curves were generated for different treatment times (0 to 25 min) at different temperatures (70, 75, and 80°C) and Weibull and first-order models were compared. Thermal inactivation data for S. nakayamae spores varied widely depending on the media formulations used, with glucose yeast peptone consistently yielding the highest D-values for the three temperatures tested. For this same medium, the D-values ranged from 25.24 ± 1.57 to 3.45 ± 0.27 min for the first-order model and from 24.18 ± 0.62 to 3.50 ± 0.24 min for the Weibull model at 70 and 80°C, respectively. The z-values determined for S. nakayamae spores were 11.91 ± 0.29°C for the Weibull model and 11.58 ± 0.43°C for the first-order model. The calculated activation energy was 200.5 ± 7.3 kJ/mol for the first-order model and 192.8 ± 22.1 kJ/mol for the Weibull model. The Weibull model consistently produced the best fit for all the survival curves. This study provides novel and precise information on thermal inactivation kinetics of S. nakayamae spores that will enable reliable thermal process calculations for eliminating this spoilage bacterium.

Determination of the Thermal Inactivation Kinetics of the Human Norovirus Surrogates, Murine Norovirus and Feline Calicivirus

2013 ◽  
Vol 76 (1) ◽  
pp. 79-84 ◽  
Author(s):  
HAYRIYE BOZKURT ◽  
DORIS H. D'SOUZA ◽  
P. MICHAEL DAVIDSON
Keyword(s):  
Thermal Inactivation ◽  
Weibull Model ◽  
Inactivation Kinetics ◽  
Feline Calicivirus ◽  
Murine Norovirus ◽  
Order Model ◽  
Human Norovirus ◽  
First Order ◽  
D Values ◽  
Kinetics Of

Studies are needed to bridge existing data gaps and determine appropriate parameters for thermal inactivation methods for human noroviruses. Cultivable surrogates, such as feline calicivirus (FCV-F9) and murine norovirus (MNV-1), have been used in the absence of human norovirus infectivity assays. This study aimed to characterize the thermal inactivation kinetics of MNV-1 and FCV-F9 at 50, 56, 60, 65, and 72°C for different treatment times (0 to 60 min). Thermal inactivation was performed using the capillary tube method with titers of 4.0 × 107 (MNV-1) and 5.8 × 108 (FCV-F9) PFU/ml in triplicate experiments, followed by standard plaque assays in duplicate for each experiment. Weibull and first-order models were compared to describe survival curve kinetics. Model fitness was investigated by comparing the regression coefficients (R2) and the chi-square (χ2) and root mean square error (RMSE) values. The D-values calculated from the first-order model (50 to 72°C) were 0.15 to 34.49 min for MNV-1 and 0.11 to 20.23 min for FCV-9. Using the Weibull model, the tD values needed to destroy 1 log PFU of MNV-1 and FCV-F9 at the same temperatures were 0.11 to 28.26 and 0.06 to 13.86 min, respectively. In terms of thermal resistance, MNV-1 was more sensitive than FCV-F9 up to 65°C. At 72°C, FCV-F9 was slightly more susceptible to heat inactivation. Results revealed that the Weibull model was more appropriate to represent the thermal inactivation behavior of both tested surrogates. The z-values were calculated using D-values for the first-order model and the tD values for the Weibull model. The z-values were 9.31 and 9.19°C for MNV-1 and 9.36 and 9.31°C for FCV-F9 for the first-order and Weibull models, respectively. This study provides more precise information than previous reports on the thermal inactivation kinetics of two norovirus surrogates for use in thermal process calculations.

Thermal Inactivation of Human Norovirus Surrogates in Spinach and Measurement of Its Uncertainty

2014 ◽  
Vol 77 (2) ◽  
pp. 276-283 ◽  
Author(s):  
HAYRIYE BOZKURT ◽  
DORIS H. D'SOUZA ◽  
P. MICHAEL DAVIDSON
Keyword(s):  
Thermal Inactivation ◽  
Weibull Model ◽  
Inactivation Kinetics ◽  
Murine Norovirus ◽  
Order Model ◽  
Human Norovirus ◽  
Test Volume ◽  
Total Uncertainty ◽  
First Order ◽  
D Values

Leafy greens, including spinach, have potential for human norovirus transmission through improper handling and/or contact with contaminated water. Inactivation of norovirus prior to consumption is essential to protect public health. Because of the inability to propagate human noroviruses in vitro, murine norovirus (MNV-1) and feline calicivirus (FCV-F9) have been used as surrogates to model human norovirus behavior under laboratory conditions. The objectives of this study were to determine thermal inactivation kinetics of MNV-1 and FCV-F9 in spinach, compare first-order and Weibull models, and measure the uncertainty associated with the process. D-values were determined for viruses at 50, 56, 60, 65, and 72°C in 2-ml vials. The D-values calculated from the first-order model (50 to 72°C) ranged from 0.16 to 14.57 min for MNV-1 and 0.15 to 17.39 min for FCV-9. Using the Weibull model, the tD for MNV-1 and FCV-F9 to destroy 1 log (D = 1) at the same temperatures ranged from 0.22 to 15.26 and 0.27 to 20.71 min, respectively. The z-values determined for MNV-1 were 11.66 ± 0.42°C using the Weibull model and 10.98 ± 0.58°C for the first-order model and for FCV-F9 were 10.85 ± 0.67°C and 9.89 ± 0.79°C, respectively. There was no difference in D- or z-value using the two models (P >0.05). Relative uncertainty for dilution factor, personal counting, and test volume were 0.005, 0.0004, and ca. 0.84%, respectively. The major contribution to total uncertainty was from the model selected. Total uncertainties for FCV-F9 for the Weibull and first-order models were 3.53 to 7.56% and 11.99 to 21.01%, respectively, and for MNV-1, 3.10 to 7.01% and 13.14 to 16.94%, respectively. Novel and precise information on thermal inactivation of human norovirus surrogates in spinach was generated, enabling more reliable thermal process calculations to control noroviruses. The results of this study may be useful to the frozen food industry in designing blanching processes for spinach to inactivate or control noroviruses.

Thermal inactivation kinetics of hepatitis A virus in spinach

2015 ◽  
Vol 193 ◽  
pp. 147-151 ◽  
Author(s):  
Hayriye Bozkurt ◽  
Xiaofei Ye ◽  
Federico Harte ◽  
Doris H. D'Souza ◽  
P. Michael Davidson
Keyword(s):  
Hepatitis A ◽  
Thermal Inactivation ◽  
Hepatitis A Virus ◽  
Inactivation Kinetics ◽  
Kinetics Of

scholarly journals Determination of Thermal Inactivation Kinetics of Hepatitis A Virus in Blue Mussel (Mytilus edulis) Homogenate

2014 ◽  
Vol 80 (10) ◽  
pp. 3191-3197 ◽  
Author(s):  
Hayriye Bozkurt ◽  
Doris H. D'Souza ◽  
P. Michael Davidson
Keyword(s):  
Thermal Inactivation ◽  
Hepatitis A Virus ◽  
Weibull Model ◽  
Order Model ◽  
Blue Mussels ◽  
First Order ◽  
Food Borne ◽  
The Times ◽  
D Values

ABSTRACTHepatitis A virus (HAV) is a food-borne enteric virus responsible for outbreaks of hepatitis associated with shellfish consumption. The objectives of this study were to determine the thermal inactivation behavior of HAV in blue mussels, to compare the first-order and Weibull models to describe the data, to calculate Arrhenius activation energy for each model, and to evaluate model efficiency by using selected statistical criteria. The times required to reduce the population by 1 log cycle (D-values) calculated from the first-order model (50 to 72°C) ranged from 1.07 to 54.17 min for HAV. Using the Weibull model, the times required to destroy 1 log unit (tD= 1) of HAV at the same temperatures were 1.57 to 37.91 min. At 72°C, the treatment times required to achieve a 6-log reduction were 7.49 min for the first-order model and 8.47 min for the Weibull model. The z-values (changes in temperature required for a 90% change in the log D-values) calculated for HAV were 15.88 ± 3.97°C (R2, 0.94) with the Weibull model and 12.97 ± 0.59°C (R2, 0.93) with the first-order model. The calculated activation energies for the first-order model and the Weibull model were 165 and 153 kJ/mol, respectively. The results revealed that the Weibull model was more appropriate for representing the thermal inactivation behavior of HAV in blue mussels. Correct understanding of the thermal inactivation behavior of HAV could allow precise determination of the thermal process conditions to prevent food-borne viral outbreaks associated with the consumption of contaminated mussels.

Temperature Resistance of Salmonella in Low–Water Activity Whey Protein Powder as Influenced by Salt Content

2014 ◽  
Vol 77 (4) ◽  
pp. 631-634 ◽  
Author(s):  
S. M. SANTILLANA FARAKOS ◽  
J. W. HICKS ◽  
J. F. FRANK
Keyword(s):  
Whey Protein ◽  
Water Activity ◽  
Survival Data ◽  
Thermal Inactivation ◽  
Salt Content ◽  
Weibull Model ◽  
Inactivation Kinetics ◽  
Model Parameters ◽  
Conflicting Information ◽  
Kinetics Of

Salmonella can survive in low–water activity (aw) foods for long periods of time. Water activity and the presence of solutes may affect its survival during heating. Low-aw products that contain sodium levels above 0.1% (wt/wt) and that have been involved in major Salmonella outbreaks include peanut products and salty snacks. Reduced aw protects against thermal inactivation. There is conflicting information regarding the role of salt. The aim of this study was to determine whether NaCl influences the survival of Salmonella in low-aw whey protein powder independent of aw at 70 and 80°C. Whey protein powders of differing NaCl concentrations (0, 8, and 17% [wt/wt]) were equilibrated to target aw levels 0.23, 0.33, and 0.58. Powders were inoculated with Salmonella, vacuum sealed, and stored at 70 and 80°C for 48 h. Cells were recovered on nonselective differential media. Survival data were fit with the Weibull model, and first decimal reduction times (δ) (measured in minutes) and shape factor values (β) were estimated. The influence of temperature, aw, and salinity on Weibull model parameters (δ and β) was analyzed using multiple linear regression. Results showed that aw significantly influenced the survival of Salmonella at both temperatures, increasing resistance at decreasing aw. Sodium chloride did not provide additional protection or inactivation of Salmonella at any temperature beyond that attributed to aw. The Weibull model described the survival kinetics of Salmonella well, with R2 adj and root mean square error values ranging from 0.59 to 0.97 and 0.27 to 1.07, respectively. Temperature and aw influenced δ values (P < 0.05), whereas no significant differences were found between 70 and 80°C among the different salt concentrations (P > 0.05). b values were not significantly influenced by temperature, aw, or % NaCl (P > 0.05). This study indicates that information on salt content in food may not help improve predictions on the inactivation kinetics of Salmonella in low-aw protein systems within the aw levels and temperatures studied.

Thermal Inactivation at High Temperatures and Regeneration of Green Asparagus Peroxidase

1996 ◽  
Vol 59 (10) ◽  
pp. 1065-1071 ◽  
Author(s):  
CARMEN RODRIGO ◽  
MIGUEL RODRIGO ◽  
ANDRÉS ALVARRUIZ ◽  
ANA FRÍGOLA
Keyword(s):  
Enzyme Activity ◽  
Peroxidase Activity ◽  
Thermal Inactivation ◽  
Maximum Activity ◽  
Small Samples ◽  
Inactivation Kinetics ◽  
Optimum Conditions ◽  
First Order ◽  
Kinetics Of ◽  
Green Asparagus

A spectrophotometric method was developed for determining the peroxidase activity of green asparagus in small samples. The optimum conditions for the analysis in the cuvette were 45 mM of H2O2 36 mM of guaiacol, and pH 7. The method can be used to determine enzyme activity at up to two decimal reductions. A study was performed of the regeneration and inactivation kinetics of the enzyme when heated between 90 and 125°C. Regenerated asparagus peroxidase reached its maximum activity after being stored 6 days at 25°C. The regenerated enzyme followed first-order inactivation kinetics, showing an Ea = 13.62 kcal/mol and k100°C = 2.07 min−1.

Thermal Inactivation Kinetics of Salmonella and Enterococcus faecium NRRL-B2354 on whole chia seeds (Salvia hispanica L.)

2021 ◽  
Author(s):  
Soon Kiat Lau ◽  
Rajendra Panth ◽  
Byron D Chaves ◽  
Curtis L Weller ◽  
Jeyamkondan Subbiah
Keyword(s):  
Enterococcus Faecium ◽  
Thermal Inactivation ◽  
Fatty Acid Content ◽  
Information Criterion ◽  
Weibull Model ◽  
Inactivation Kinetics ◽  
Primary Model ◽  
Log Linear ◽  
Kinetics Of ◽  
Thermal Pasteurization

Intervention technologies for inactivating Salmonella in whole chia seeds are currently limited. The determination of the thermal inactivation kinetics of Salmonella o n chia seeds and selection of an appropriate nonpathogenic surrogate will provide a knowledge foundation for selecting and optimizing thermal pasteurization processes for chia seeds. In this study, chia seed samples from three separate production lots were inoculated with a five strain Salmonella cocktail or Enterococcus faecium NRRL-B2354 and equilibrated to 0.53 aw at room temperature (25 °C). After equilibration for at least three days, the inoculated seeds were subjected to isothermal treatments at 80, 85, or 90 °C. Samples were taken out at six timepoints and enumerated for survivors. Initial dilution of whole chia seeds was performed in a filter bag at a 1:30 ratio after it was shown to have similar recovery to grinding the seeds. Survivor data were fitted to consolidated models consisting of a primary model (log-linear or Weibull) and one secondary model (Bigelow). E. faecium exhibited higher thermal resistance than Salmonella , suggesting its suitability as a conservative nonpathogenic surrogate. The Weibull model was a better fit for the survivor data than the log-linear model for both bacteria due to its lower root mean square error and corrected Akaike’s Information Criterion values. Measurements of lipid oxidation and fatty acid content indicated a few statistically different values compared to the control samples, but the overall difference in magnitudes were relatively small. The thermal inactivation kinetics of Salmonella and E. faecium o n chia seeds as presented in this study can serve as a basis for developing thermal pasteurization processes for chia seeds.

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