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Soni A, Bremer P, Brightwell G. A Comprehensive Review of Variability in the Thermal Resistance (D-Values) of Food-Borne Pathogens-A Challenge for Thermal Validation Trials. Foods 2022; 11:4117. [PMID: 36553859 PMCID: PMC9777713 DOI: 10.3390/foods11244117] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/13/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
The thermal processing of food relies heavily on determining the right time and temperature regime required to inactivate bacterial contaminants to an acceptable limit. To design a thermal processing regime with an accurate time and temperature combination, the D-values of targeted microorganisms are either referred to or estimated. The D-value is the time required at a given temperature to reduce the bacterial population by 90%. The D-value can vary depending on various factors such as the food matrix, the bacterial strain, and the conditions it has previously been exposed to; the intrinsic properties of the food (moisture, water activity, fat content, and pH); the method used to expose the microorganism to the thermal treatment either at the laboratory or commercial scale; the approach used to estimate the number of survivors; and the statistical model used for the analysis of the data. This review focused on Bacillus cereus, Cronobacter sakazakii, Escherichia coli, Listeria monocytogenes, and Clostridium perfringens owing to their pathogenicity and the availability of publications on their thermal resistance. The literature indicates a significant variation in D-values reported for the same strain, and it is concluded that when designing thermal processing regimes, the impact of multiple factors on the D-values of a specific microorganism needs to be considered. Further, owing to the complexity of the interactions involved, the effectiveness of regimes derived laboratory data must be confirmed within industrial food processing settings.
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Affiliation(s)
- Aswathi Soni
- Food System Integrity, Smart Foods and Bioproducts, AgResearch Ltd., Palmerston North 4414, New Zealand
| | - Phil Bremer
- Department of Food Science, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
- New Zealand Food Safety Science and Research Centre, Palmerston North 4474, New Zealand
| | - Gale Brightwell
- Food System Integrity, Smart Foods and Bioproducts, AgResearch Ltd., Palmerston North 4414, New Zealand
- New Zealand Food Safety Science and Research Centre, Palmerston North 4474, New Zealand
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2
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A comparative study for determination of thermal inactivation parameters of Salmonella in high gel and standard egg white powder using three methods. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.114185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Lau SK, Wei X, Kirezi N, Panth R, See A, Subbiah J. A Comparison of Three Methods for Determining Thermal Inactivation Kinetics: A Case Study on Salmonella enterica in Whole Milk Powder. J Food Prot 2021; 84:521-530. [PMID: 33159446 DOI: 10.4315/jfp-20-232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/30/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Different methods for determining the thermal inactivation kinetics of microorganisms can result in discrepancies in thermal resistance values. In this study, thermal resistance of Salmonella in whole milk powder was determined with three methods: thermal death time (TDT) disk in water bath, pouches in water bath, and the TDT Sandwich system. Samples from three production lots of whole milk powder were inoculated with a five-strain Salmonella cocktail and equilibrated to a water activity of 0.20. The samples were then subjected to three isothermal treatments at 75, 80, or 85°C. Samples were removed at six time points and cultures were enumerated for survivors. The inactivation data were fitted to two consolidated models: two primary models (log linear and Weibull) and one secondary model (Bigelow). Normality testing indicated that all the model parameters were normally distributed. None of the model parameters for both consolidated models were significantly different (α = 0.05). The amount of inactivation during the come-up time was also not significantly different among the methods (α = 0.05). However, the TDT Sandwich resulted in less inactivation during the come-up time and overall less variation in model parameters. The survivor data from all three methods were combined and fitted to both consolidated models. The Weibull had a lower root mean square error and a better fit, according to the corrected Akaike's information criterion. The three thermal treatment methods produced results that were not significantly different; thus, the methods are interchangeable, at least for Salmonella in whole milk powder. Comparisons with more methods, other microorganisms, and larger varieties of food products using the same framework presented in this study could provide guidance for standardizing thermal inactivation kinetics studies for microorganisms in foods. HIGHLIGHTS
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Affiliation(s)
- Soon Kiat Lau
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.]).,Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68583
| | - Xinyao Wei
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Nina Kirezi
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Rajendra Panth
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Arena See
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Jeyamkondan Subbiah
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.]).,Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68583.,Department of Food Science, University of Arkansas, System Division of Agriculture, Fayetteville, Arkansas 72704, USA
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4
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Lau SK, Subbiah J. TDT Sandwich: An open source dry heat system for characterizing the thermal resistance of microorganisms. HARDWAREX 2020; 8:e00114. [PMID: 35498246 PMCID: PMC9041244 DOI: 10.1016/j.ohx.2020.e00114] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/03/2020] [Accepted: 06/04/2020] [Indexed: 06/14/2023]
Abstract
The determination of the thermal death kinetics of microorganisms has traditionally been performed with liquid baths which have some disadvantages such as liquid spillage and liquid infiltration into samples. The TDT Sandwich was developed as a free, open source alternative that utilizes dry heat. The system is capable of heating samples up to 140 °C and maintaining it within 0.2 °C of the target temperature. Other features of the TDT Sandwich include adjustable heating rates up to approximately 100 °C/min, real-time display and recording of temperature readings at a nominal rate of 5 Hz, an optional thermocouple for acquiring temperature of samples, built-in heating timer, and customizable operating parameters. The modular nature of the TDT Sandwich allows multiple units to be connected to a computer or laptop. Operation of the TDT Sandwich is done through a computer program which, along with the build instructions and microcontroller program, are open source and are available for free to the public at https://doi.org/10.17605/OSF.IO/5Q3Y7.
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Affiliation(s)
- Soon Kiat Lau
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jeyamkondan Subbiah
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Food Science, University of Arkansas, Fayetteville, AR, USA
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5
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Are Antimicrobial Interventions Associated with Heat-Resistant Escherichia coli on Meat? Appl Environ Microbiol 2020; 86:AEM.00512-20. [PMID: 32303544 DOI: 10.1128/aem.00512-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 04/14/2020] [Indexed: 01/01/2023] Open
Abstract
Decontamination practices, which often involve thermal treatments, are routinely performed in beef packing plants and have generally improved the safety of meat in North America. We investigated whether Escherichia coli in the beef production chain is becoming more heat resistant due to those treatments. Cattle isolates (n = 750) included seven serogroups (O157, O103, O111, O121, O145, O26, and O45) which were collected between 2002 and 2017. Beef plant isolates (n = 700) from carcasses, fabrication equipment, and beef products were included. Heat resistance was determined in Luria-Bertani broth at 60°C and by PCR screening for the locus of heat resistance (LHR). The decimal reduction for E. coli at 60°C (D 60ºC values) ranged from 0 to 7.54 min, with 97.2% of the values being <2 min. The prevalence of E. coli with D 60ºC values of >2 min was not significantly different (P > 0.05) among cattle and meat plant isolates. E. coli from equipment before sanitation (median, 1.03 min) was more heat resistant than that after sanitation (median, 0.9 min). No significant difference in D 60ºC values was observed among E. coli isolates from different years, from carcasses before and after antimicrobial interventions, or from before and during carcass chilling. Of all isolates, 1.97% harbored LHR, and the LHR-positive isolates had greater median D 60ºC values than the LHR-negative isolates (3.25 versus 0.96 min). No increase in heat resistance in E. coli was observed along the beef production chain or with time.IMPORTANCE The implementation of multiple hurdles in the beef production chain has resulted in substantial improvement in the microbial safety of beef in Canada. In this study, we characterized a large number of Escherichia coli isolates (n = 1,450) from various sources/stages of beef processing to determine whether the commonly used antimicrobial interventions would give rise to heat-resistant E. coli on meat, which in turn may require alternatives to the current control of pathogens and/or modifications to the current cooking recommendations for meat. The findings show that the degree and rate of heat resistance in E. coli did not increase along the production chain or with time. This furthers our understanding of man-made ecological niches that are required for the development of heat resistance in E. coli.
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6
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Effect of moderate electric field pretreatment in combination with ozonation on inactivation of Escherichia coli K12 in intact shell eggs. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.109338] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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7
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Vatankhah H, John D, Ramaswamy HS. Evaluation of thermal and nonthermal treatment of margarine: Pasteurization process efficiency, kinetics of microbial destruction, and changes in thermophysical characteristics. J FOOD PROCESS PRES 2020. [DOI: 10.1111/jfpp.14323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hamed Vatankhah
- Department of Food Science and Agricultural Chemistry Macdonald Campus of McGill University Montréal QC Canada
| | - Dalia John
- Department of Food Science and Agricultural Chemistry Macdonald Campus of McGill University Montréal QC Canada
| | - Hosahalli S. Ramaswamy
- Department of Food Science and Agricultural Chemistry Macdonald Campus of McGill University Montréal QC Canada
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8
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Zhou Z, Zuber S, Campagnoli M, Putallaz T, Devlieghere F, Uyttendaele M. Effect of mild steaming treatment on the inactivation of Salmonella, Listeria monocytogenes, Escherichia coli O157:H7 and their surrogates on black peppercorns. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.106726] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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9
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Hu Z, Rohde A, McMullen L, Gänzle M. Effect of sodium chloride and chitosan on the inactivation of heat resistant or Shiga-toxin producing Escherichia coli during grilling of burger patties. Int J Food Microbiol 2019; 308:108308. [PMID: 31466020 DOI: 10.1016/j.ijfoodmicro.2019.108308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 11/25/2022]
Abstract
Cattle are a reservoir for enterohemorrhagic Escherichia coli (EHEC), and ground beef is a major vehicle for human infection with EHEC. Heat resistance of E. coli, including EHEC, is impacted by NaCl and other additives. This study aimed to evaluate the effect of NaCl and other additives on the heat resistance of E. coli in beef patties. E. coli AW1.7ΔpHR1(pLHR) with the locus of heat resistance (LHR), E. coli AW1.7ΔpHR1(pRK767) without LHR, or a 5-strain cocktail of EHEC were inoculated (107-108 CFU/g) into ground beef (15% fat) with NaCl (0-3%), marinade, carvacrol (0.1%), potassium lactate (3%) or chitosan (0.1%) following different protocols. Patties were grilled immediately, or stored in sterile bags for two days at 4 °C prior to grilling to a core temperature of 71 °C. Cell counts of LHR-positive E. coli AW1.7ΔpHR1(pLHR) were higher than that of the isogenic LHR-negative E. coli AW1.7ΔpHR1(pRK767) by >3 log10 (CFU/g) after cooking. Addition of 3% NaCl increased survival of E. coli AW1.7ΔpHR1(pRK767) and the EHEC cocktail while cell counts of the heat resistant strains were not changed. A protective effect of NaCl was not observed with E. coli AW1.7ΔpHR1(pRK767) or EHEC if cells of E. coli were cooled to 4 °C prior to mixing with cold meat and NaCl, indicating that the response of E. coli to osmotic shock contributes to this effect. Chitosan enhanced the thermal destruction of LHR-positive E. coli AW1.7ΔpHR1(pLHR) in ground beef stored at 4 °C for 2 days, while marinade, carvacrol, or potassium lactate had no such effect, indicating that chitosan can be characterized as an effective hurdle concept to reduce the potential risk of LHR-positive pathogen to meat safety.
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Affiliation(s)
- Ziyi Hu
- University of Alberta, Dept. of Agricultural, Food and Nutritional Science, Edmonton, Canada
| | - Alina Rohde
- University of Alberta, Dept. of Agricultural, Food and Nutritional Science, Edmonton, Canada
| | - Lynn McMullen
- University of Alberta, Dept. of Agricultural, Food and Nutritional Science, Edmonton, Canada
| | - Michael Gänzle
- University of Alberta, Dept. of Agricultural, Food and Nutritional Science, Edmonton, Canada; Hubei University of Technology, College of Bioengineering and Food Science, Wuhan, PR China.
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10
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Use of protective culture to control the growth of Listeria monocytogenes and Salmonella typhimurium in ready-to-eat cook-chill products. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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11
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de Souza Figueiredo EE, Yang X, Zhang P, Reuter T, Stanford K. Comparison of heating block and water bath methods to determine heat resistance in Shiga-toxin producing Escherichia coli with and without the locus of heat resistance. J Microbiol Methods 2019; 164:105679. [PMID: 31351872 DOI: 10.1016/j.mimet.2019.105679] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/24/2019] [Accepted: 07/24/2019] [Indexed: 10/26/2022]
Abstract
This study found variability in the time required for tubes of media in heating block wells to reach 60 °C, resulting in significant effects on heat resistance measurements. To determine the extent that methodology changed heat resistance measurements, we compared the heat resistance of Shiga-toxin producing Escherichia coli (STEC) strains with and without the locus of heat resistance (LHR) using both heating block and water bath methods. A total of 34 strains of STEC were used along with a generic E. coli which has been identified as heat-resistant and used as a positive control. The E. coli strains were incubated in a water bath and a heating block set at 60 °C to determine come up time to 60 °C (T0) and for 6 additional minutes (T6) to calculate the D60 value. After incubation, the colony forming units (CFU) were enumerated and mean log CFU/mL from biological replicates was calculated. To compare reductions from T0 to T6, standard deviations among replicates within heating method and correlation of the D60 values generated across methods were determined using Mixed model and Correlation analyses. Our findings indicate that the method chosen to evaluate heat resistance of E. coli can dramatically influence results as there was not a significant correlation between D60 values for the same isolate determined by water bath and heating block methods. The water bath method generates more reliable and consistent heat resistance data and should be used in future evaluations of heat resistance in E. coli. Moreover, PCR screening for the LHR would only be moderately useful for predicting phenotypic heat-resistance of E. coli. Considering water bath data only, LHR-positive STEC isolates were either moderately heat-resistant (1 to 5 log reduction) or heat-sensitive (> 5 log reduction). As LHR-negative STEC were also moderately heat-resistant, prediction of phenotypic heat resistance from genotype requires further refinement.
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Affiliation(s)
| | - Xianqin Yang
- Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB T4L 1W1, Canada
| | - Peipei Zhang
- Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB T4L 1W1, Canada
| | - Tim Reuter
- Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, AB T1J 4V6, Canada
| | - Kim Stanford
- Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, AB T1J 4V6, Canada.
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12
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Heat resistance of Salmonella Enteritidis in four different liquid egg products and the performance and equivalent conditions of Ministry of Food and Drug Safety of South Korea and US Department of Agriculture protocols. Food Control 2018. [DOI: 10.1016/j.foodcont.2018.06.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Li R, Kou X, Zhang L, Wang S. Inactivation kinetics of food-borne pathogens subjected to thermal treatments: a review. Int J Hyperthermia 2018; 34:177-188. [DOI: 10.1080/02656736.2017.1372643] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Affiliation(s)
- Rui Li
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Xiaoxi Kou
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Lihui Zhang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
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14
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Hu M, Gurtler JB. Selection of Surrogate Bacteria for Use in Food Safety Challenge Studies: A Review. J Food Prot 2017; 80:1506-1536. [PMID: 28805457 DOI: 10.4315/0362-028x.jfp-16-536] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Nonpathogenic surrogate bacteria are prevalently used in a variety of food challenge studies in place of foodborne pathogens such as Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, and Clostridium botulinum because of safety and sanitary concerns. Surrogate bacteria should have growth characteristics and/or inactivation kinetics similar to those of target pathogens under given conditions in challenge studies. It is of great importance to carefully select and validate potential surrogate bacteria when verifying microbial inactivation processes. A validated surrogate responds similar to the targeted pathogen when tested for inactivation kinetics, growth parameters, or survivability under given conditions in agreement with appropriate statistical analyses. However, a considerable number of food studies involving putative surrogate bacteria lack convincing validation sources or adequate validation processes. Most of the validation information for surrogates in these studies is anecdotal and has been collected from previous publications but may not be sufficient for given conditions in the study at hand. This review is limited to an overview of select studies and discussion of the general criteria and approaches for selecting potential surrogate bacteria under given conditions. The review also includes a list of documented bacterial pathogen surrogates and their corresponding food products and treatments to provide guidance for future studies.
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Affiliation(s)
- Mengyi Hu
- 1 U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Food Safety and Intervention Technologies Research Unit, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038-8551.,2 Department of Culinary Arts and Food Science, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104-30, USA
| | - Joshua B Gurtler
- 1 U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Food Safety and Intervention Technologies Research Unit, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038-8551
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15
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Lechevalier V, Guérin-Dubiard C, Anton M, Beaumal V, David Briand E, Gillard A, Le Gouar Y, Musikaphun N, Tanguy G, Pasco M, Dupont D, Nau F. Pasteurisation of liquid whole egg: Optimal heat treatments in relation to its functional, nutritional and allergenic properties. J FOOD ENG 2017. [DOI: 10.1016/j.jfoodeng.2016.10.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Li H, Gänzle M. Some Like It Hot: Heat Resistance of Escherichia coli in Food. Front Microbiol 2016; 7:1763. [PMID: 27857712 PMCID: PMC5093140 DOI: 10.3389/fmicb.2016.01763] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/20/2016] [Indexed: 11/13/2022] Open
Abstract
Heat treatment and cooking are common interventions for reducing the numbers of vegetative cells and eliminating pathogenic microorganisms in food. Current cooking method requires the internal temperature of beef patties to reach 71°C. However, some pathogenic Escherichia coli such as the beef isolate E. coli AW 1.7 are extremely heat resistant, questioning its inactivation by current heat interventions in beef processing. To optimize the conditions of heat treatment for effective decontaminations of pathogenic E. coli strains, sufficient estimations, and explanations are necessary on mechanisms of heat resistance of target strains. The heat resistance of E. coli depends on the variability of strains and properties of food formulations including salt and water activity. Heat induces alterations of E. coli cells including membrane, cytoplasm, ribosome and DNA, particularly on proteins including protein misfolding and aggregations. Resistant systems of E. coli act against these alterations, mainly through gene regulations of heat response including EvgA, heat shock proteins, σE and σS, to re-fold of misfolded proteins, and achieve antagonism to heat stress. Heat resistance can also be increased by expression of key proteins of membrane and stabilization of membrane fluidity. In addition to the contributions of the outer membrane porin NmpC and overcome of osmotic stress from compatible solutes, the new identified genomic island locus of heat resistant performs a critical role to these highly heat resistant strains. This review aims to provide an overview of current knowledge on heat resistance of E. coli, to better understand its related mechanisms and explore more effective applications of heat interventions in food industry.
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Affiliation(s)
- Hui Li
- Department of Agricultural, Food and Nutritional Science, University of Alberta, EdmontonAB, Canada
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, EdmontonAB, Canada
- College of Bioengineering and Food Science, Hubei University of TechnologyHubei, China
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17
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Kou XX, Li R, Hou LX, Huang Z, Ling B, Wang SJ. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods. Sci Rep 2016; 6:30758. [PMID: 27465120 PMCID: PMC4964582 DOI: 10.1038/srep30758] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/08/2016] [Indexed: 11/09/2022] Open
Abstract
Knowledge of bacteria's heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria's heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample's thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS's performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria's thermo-tolerances.
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Affiliation(s)
- Xiao-xi Kou
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Rui Li
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Li-xia Hou
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Zhi Huang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Bo Ling
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shao-jin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA
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18
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Godwin S, Maughan C, Chambers E. Food Safety: Recommendations for Determining Doneness in Consumer Egg Dish Recipes and Measurement of Endpoint Temperatures When Recipes Are Followed. Foods 2016; 5:E45. [PMID: 28231140 PMCID: PMC5302401 DOI: 10.3390/foods5030045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 06/17/2016] [Accepted: 06/20/2016] [Indexed: 11/16/2022] Open
Abstract
Many consumers do not follow recommended food safety practices for cooking egg dishes, such as pies, quiches, and casseroles, potentially leading to foodborne illnesses such as Salmonellosis. The United States Department of Agriculture (USDA) recommends cooking egg mixtures until the center reaches 71 °C (160 °F). The objectives of this study were to determine what endpoint temperature information consumers receive from egg dish recipes, and if recipes would lead to safe temperatures when followed. Egg dish recipes (n = 226) from 65 websites, 50 cookbooks, and nine magazine titles (multiple issues of each) were analyzed. Time was the most frequently used indicator, given in 92% of the recipes, with 15% using only time. Other indicators included: set (89), browned (76), clean toothpick/knife (60), puffed (27), and jiggled (13). Only two recipes indicated final endpoint temperatures. Three recipes (a pie, a quiche, and an egg casserole) were chosen and prepared in triplicate to see if they would reach recommended temperatures. The pie and quiche were still liquid at 71 °C, and were well over the recommended temperature when cooked according to instructions, but the egg casserole was not consistently above 71 °C, when the recipe instructions indicated it was done and the center was light brown and "jiggled" This research indicates that consumers are not receiving information on endpoint temperatures in egg recipes, but the likelihood of foodborne illness is low since most dishes probably be cooked past the recommended temperature before the consumer considers them done unless there are many inclusions that may absorb liquid and reduce the appearance of liquid in the dish.
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Affiliation(s)
- Sandria Godwin
- Tennessee State University, 3500 John A. Merritt Boulevard, Nashville, TN 37209, USA.
| | - Curtis Maughan
- Sensory Analysis Center, Kansas State University, Manhattan, KS 66502, USA.
| | - Edgar Chambers
- Sensory Analysis Center, Kansas State University, Manhattan, KS 66502, USA.
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Alkaya GB, Erdogdu F, Halkman AK, Ekiz HI. Surface decontamination of whole-shell eggs using far-infrared radiation. FOOD AND BIOPRODUCTS PROCESSING 2016. [DOI: 10.1016/j.fbp.2016.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Daryaei H, Balasubramaniam V, Yousef AE, Legan JD, Tay A. Lethality enhancement of pressure-assisted thermal processing against Bacillus amyloliquefaciens spores in low-acid media using antimicrobial compounds. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.05.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Peng J, Tang J, Barrett DM, Sablani SS, Anderson N, Powers JR. Thermal pasteurization of ready-to-eat foods and vegetables: Critical factors for process design and effects on quality. Crit Rev Food Sci Nutr 2015; 57:2970-2995. [DOI: 10.1080/10408398.2015.1082126] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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22
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Risk to public and/or animal health of the treatment of dead‐in‐shell chicks (Category 2 material) to be used as raw material for the production of biogas or compost with Category 3 approved method. EFSA J 2015. [DOI: 10.2903/j.efsa.2015.4306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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23
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Microbiological efficacy of pressure assisted thermal processing and natural extracts against Bacillus amyloliquefaciens spores suspended in deionized water and beef broth. FOOD AND BIOPRODUCTS PROCESSING 2015. [DOI: 10.1016/j.fbp.2015.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Garcia-Hernandez R, McMullen L, Gänzle MG. Development and validation of a surrogate strain cocktail to evaluate bactericidal effects of pressure on verotoxigenic Escherichia coli. Int J Food Microbiol 2015; 205:16-22. [PMID: 25866907 DOI: 10.1016/j.ijfoodmicro.2015.03.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/19/2015] [Accepted: 03/24/2015] [Indexed: 12/21/2022]
Abstract
Many strains of verotoxigenic Escherichia coli (VTEC) are highly resistant to pressure. To facilitate future studies to improve the elimination of VTEC by pressure processing of food, this study developed and validated a cocktail of non-pathogenic strains of E. coli with equal or higher resistance to pressure when compared to pressure resistant strains of VTEC. Strains of E. coli obtained from a beef processing plant were screened for their resistance to heat and pressure. Treatments were carried out in LB broth. Cell counts of 3 out of 16 strains were reduced by 5-6 log (cfu/mL) after 30 min at 60 °C, and cell counts of 10 out of 16 strains were reduced by 5-6 log (cfu/mL) after 30 min at 40 °C and 400 MPa. All highly heat resistant strains were also pressure resistant but not all pressure resistant strains were also heat resistant. Pressure resistant and -sensitive strains of E. coli were treated in presence of 0 or 2% NaCl and at 3, 20, or 40 °C. The effect of these parameters on the lethality of pressure treatments was comparable for all strains. The addition of 2% NaCl did not increase pressure resistance. The bactericidal effect of treatments at 3 and 20 °C and 600 MPa was comparable but inactivation of E. coli was faster at 40 °C and 600 MPa. The resistance to treatment with 600 MPa at 20 °C of a cocktail of 5 non-pathogenic strains of E. coli was compared to a 5 strain cocktail of pressure resistant VTEC. Treatments were performed in ground beef containing 15% fat. Survival and sublethal injury of the two cocktails was comparable; cell counts of beef inoculated with either cocktail were reduced by about 4 log (cfu/mL) after 30 min of treatment. In conclusion, this study validated a cocktail of non-pathogenic strains of E. coli for use as surrogate organisms in studies on the elimination of E. coli by pressure.
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Affiliation(s)
| | - Lynn McMullen
- University of Alberta, Department of Agricultural, Food and Nutritional Science, Edmonton, Canada
| | - Michael G Gänzle
- University of Alberta, Department of Agricultural, Food and Nutritional Science, Edmonton, Canada.
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Michael M, Phebus R, Thippareddi H, Subbiah J, Birla S, Schmidt K. Validation of radio-frequency dielectric heating system for destruction of Cronobacter sakazakii and Salmonella species in nonfat dry milk. J Dairy Sci 2014; 97:7316-24. [DOI: 10.3168/jds.2013-7862] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 08/19/2014] [Indexed: 11/19/2022]
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26
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Ling B, Tang J, Kong F, Mitcham EJ, Wang S. Kinetics of Food Quality Changes During Thermal Processing: a Review. FOOD BIOPROCESS TECH 2014. [DOI: 10.1007/s11947-014-1398-3] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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27
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Inactivation kinetics for Salmonella Enteritidis in potato omelet using microwave heating treatments. Food Control 2014. [DOI: 10.1016/j.foodcont.2014.03.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Scientific Opinion on the public health risks of table eggs due to deterioration and development of pathogens. EFSA J 2014. [DOI: 10.2903/j.efsa.2014.3782] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Shi Y, Tang J, Yue T, Rasco B, Wang S. Pasteurizing Cold Smoked Salmon (Oncorhynchus nerka): Thermal Inactivation Kinetics ofListeria monocytogenesandListeria innocua. JOURNAL OF AQUATIC FOOD PRODUCT TECHNOLOGY 2014. [DOI: 10.1080/10498850.2013.808303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Amado IR, Vázquez JA, Fuciños P, Méndez J, Pastrana L. Optimization of Antimicrobial Combined Effect of Organic Acids and Temperature on Foodborne Salmonella and Escherichia coli in Cattle Feed by Response Surface Methodology. Foodborne Pathog Dis 2013; 10:1030-6. [DOI: 10.1089/fpd.2013.1559] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Isabel Rodríguez Amado
- Departamento de Química Analítica y Alimentaria, Facultad de Ciencias de Ourense, Universidad de Vigo, Ourense, Spain
- Grupo de Reciclado y Valorización de Materiales Residuales (REVAL), Instituto de Investigaciones Marinas-IIM (CSIC), Vigo, Pontevedra, Spain
| | - Jose Antonio Vázquez
- Grupo de Reciclado y Valorización de Materiales Residuales (REVAL), Instituto de Investigaciones Marinas-IIM (CSIC), Vigo, Pontevedra, Spain
| | - Pablo Fuciños
- Departamento de Química Analítica y Alimentaria, Facultad de Ciencias de Ourense, Universidad de Vigo, Ourense, Spain
- Grupo de Reciclado y Valorización de Materiales Residuales (REVAL), Instituto de Investigaciones Marinas-IIM (CSIC), Vigo, Pontevedra, Spain
| | - Jesús Méndez
- Cooperativas Orensanas Sociedad Cooperativa Ltda (COREN), Polígono San Ciprián de Viñas, Ourense, Spain
| | - Lorenzo Pastrana
- Departamento de Química Analítica y Alimentaria, Facultad de Ciencias de Ourense, Universidad de Vigo, Ourense, Spain
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Aamir M, Ovissipour M, Sablani SS, Rasco B. Predicting the Quality of Pasteurized Vegetables Using Kinetic Models: A Review. INTERNATIONAL JOURNAL OF FOOD SCIENCE 2013; 2013:271271. [PMID: 26904594 PMCID: PMC4745515 DOI: 10.1155/2013/271271] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 06/19/2013] [Accepted: 06/26/2013] [Indexed: 11/21/2022]
Abstract
A resurgence in interest examining thermal pasteurization technologies has been driven by demands for "cleaner" labeling and the need of organic and natural foods markets for suitable preventive measures to impede microbial growth and extend shelf life of minimally processed foods and ready-to-eat foods with a concomitant reduction in the use of chemical preservatives. This review describes the effects of thermal pasteurization on vegetable quality attributes including altering flavor and texture to improve consumer acceptability, stabilizing color, improving digestibility, palatability and retaining bioavailability of important nutrients, and bioactive compounds. Here, we provide kinetic parameters for inactivation of viral and bacterial pathogens and their surrogates and marker enzymes used to monitor process effectiveness in a variety of plant food items. Data on thermal processing protocols leading to higher retention and bioactivity are also presented. Thermal inactivation of foodborne viruses and pathogenic bacteria, specifically at lower pasteurization temperatures or via new technologies such as dielectric heating, can lead to greater retention of "fresh-like" properties.
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Affiliation(s)
- Muhammad Aamir
- School of Food Science, Washington State University, Pullman, WA 99164-6376, USA
| | | | - Shyam S. Sablani
- Department of Biological System Engineering, Washington State University, Pullman, WA 99164-6120, USA
| | - Barbara Rasco
- School of Food Science, Washington State University, Pullman, WA 99164-6376, USA
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Vasan A, Leong WM, Ingham SC, Ingham BH. Thermal tolerance characteristics of non-O157 Shiga toxigenic strains of Escherichia coli (STEC) in a beef broth model system are similar to those of O157:H7 STEC. J Food Prot 2013; 76:1120-8. [PMID: 23834785 DOI: 10.4315/0362-028x.jfp-12-500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with illness are O26, O45, O103, O111, O121, and O145. In the United States, these serogroups are considered adulterants in raw nonintact beef. To begin to understand the behavior of these pathogens in meat systems, we compared the thermal tolerance of acid-adapted cells of non-O157 STEC and O157:H7 STEC in a beef-derived broth. D58°C-values were determined for at least three strains per serogroup, and D54.6°C-values and D63.6°C-values were determined for one strain per serogroup. Each strain was grown to stationary phase in brain heart infusion broth (BHIB; pH 7.0) and inoculated into prewarmed BHIB in a shaking water bath for thermotolerance experiments at 54.6, 58.0, or 63.6°C (three trials per strain). Samples were heated for up to 160 min at 54.6°C, 3 min at 58.0°C, or 45 s at 63.6°C, with periodic sampling followed by rapid cooling and plating on modified Levine's eosin methylene blue agar. For each strain and temperature, the log CFU per milliliter was plotted versus time, and D-values were determined. Across all strains, the least and most heat tolerant STEC serogroups at 58°C were O145 and O157, respectively. D58°C-values in BHIB ranged from 0.44 min for an O145 strain to 1.42 min for an O157:H7 strain. D58°C-values for O157 STEC strains were significantly higher than those for at least one strain in each of the non-O157 STEC serogroups (P < 0.05) except for serogroup O103. At 54.6°C, the most heat-resistant STEC strain belonged to serogroup O103 and was significantly more heat tolerant than the O157:H7 strains (P < 0.05). Grouping the strains, there were no significant differences in heat tolerance between O157 and non-O157 STEC at 63.6°C (P ≥ 0.05). The z-values for non-O157 STEC strains were comparable to those for O157:H7 STEC strains (P ≥ 0.05), ranging from 4.10 to 5.21°C. These results suggest that thermal processing interventions that target destruction of E. coli O157:H7 may have adequate lethality against non-O157 STEC.
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Affiliation(s)
- Akhila Vasan
- Department of Food Science, University of Wisconsin-Madison, 1605 Linden Drive, Madison, Wisconsin 53706, USA
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Whole-genome transcriptional analysis of Escherichia coli during heat inactivation processes related to industrial cooking. Appl Environ Microbiol 2013; 79:4940-50. [PMID: 23770902 DOI: 10.1128/aem.00958-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli K-12 was grown to the stationary phase, for maximum physiological resistance, in brain heart infusion (BHI) broth at 37°C. Cells were then heated at 58°C or 60°C to reach a process lethality value \[\mathbf{\left(}{{\mathit{F}}^{\mathit{o}}}_{\mathbf{70}}^{\mathbf{10}}\mathbf{\right)} \] of 2 or 3 or to a core temperature of 71°C (control industrial cooking temperature). Growth recovery and cell membrane integrity were evaluated immediately after heating, and a global transcription analysis was performed using gene expression microarrays. Only cells heated at 58°C with F(o) = 2 were still able to grow on liquid or solid BHI broth after heat treatment. However, their transcriptome did not differ from that of bacteria heated at 58°C with F(o) = 3 (P value for the false discovery rate [P-FDR] > 0.01), where no growth recovery was observed posttreatment. Genome-wide transcriptomic data obtained at 71°C were distinct from those of the other treatments without growth recovery. Quantification of heat shock gene expression by real-time PCR revealed that dnaK and groEL mRNA levels decreased significantly above 60°C to reach levels similar to those of control cells at 37°C (P < 0.0001). Furthermore, despite similar levels of cell inactivation measured by growth on BHI media after heating, 132 and 8 genes were differentially expressed at 71°C compared to 58°C and 60°C at F(o) = 3, respectively (P-FDR < 0.01). Among them, genes such as aroA, citE, glyS, oppB, and asd, whose expression was upregulated at 71°C, may be worth investigating as good biomarkers for accurately determining the efficiency of heat treatments, especially when cells are too injured to be enumerated using growth media.
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Daryaei H, Balasubramaniam VM, Legan JD. Kinetics of Bacillus cereus spore inactivation in cooked rice by combined pressure-heat treatment. J Food Prot 2013; 76:616-23. [PMID: 23575123 DOI: 10.4315/0362-028x.jfp-12-447] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The efficacy of pressure-heat treatment was evaluated for the inactivation of Bacillus cereus spores in cooked rice. The spores of B. cereus ATCC 9818 were inoculated (1.1 × 10(8) CFU/g) in a parboiled rice product (pH 6.0, water activity of 0.95) and inactivated to an undetectable level (<10 CFU/g) by treatment of 600 MPa and process temperatures of 60 to 85 °C or 0.1 MPa and 85 °C. Kinetic inactivation parameters were estimated with linear and nonlinear models. The potential recovery of injured bacteria was also evaluated during storage of the treated product for 4 weeks at 4 and 25 °C. Depending on the process temperature, a 600-MPa treatment inactivated spores by 2.2 to 3.4 log during the 30-s pressure come-up time, and to below the detection limit after 4- to 8-min pressure-holding times. In contrast, a 180-min treatment time was required to inactivate the spores to an undetectable level at 0.1 MPa and 85 °C. The decimal reduction time of spores inactivated by combined pressure-heat treatment ranged from 1.08 to 2.36 min, while it was 34.6 min at 85 °C under atmospheric conditions. The nonlinear Weibull model scale factor increased, and was inversely related to the decimal reduction time, and the shape factor decreased with increasing pressure or temperature. The recovery of injured spores was influenced by the extent of pressure-holding time and process temperature. This study suggests that combined pressure-heat treatment could be used as a viable alternative to inactivate B. cereus spores in cooked rice and extend the shelf life of the product.
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Affiliation(s)
- Hossein Daryaei
- Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, Ohio 43210, USA
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35
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Daryaei H, Balasubramaniam V. Kinetics of Bacillus coagulans spore inactivation in tomato juice by combined pressure–heat treatment. Food Control 2013. [DOI: 10.1016/j.foodcont.2012.06.031] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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36
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Villa-Rojas R, Tang J, Wang S, Gao M, Kang DH, Mah JH, Gray P, Sosa-Morales ME, López-Malo A. Thermal inactivation of Salmonella enteritidis PT 30 in almond kernels as influenced by water activity. J Food Prot 2013; 76:26-32. [PMID: 23317853 DOI: 10.4315/0362-028x.jfp-11-509] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonellosis outbreaks related to consumption of raw almonds have encouraged the scientific community to study the inactivation kinetics of pathogens in this dry commodity. However, the low moisture content of the product presents a challenge for thermal control, because the time required to achieve the desired thermal inactivation of microorganisms increases sharply with reduced moisture content and water activity. In this study, we explored and modeled the heat inactivation of Salmonella enterica serovar Enteritidis PT 30 in almond cultivar 'Nonpareil' kernel flour at four water activity (a(w)) values (0.601, 0.720, 0.888, and 0.946) using four temperatures for each a(w). The results showed that the inactivation was well fitted by both Weibull distribution (R(2) = 0.93 to 1.00) and first-order kinetics (R(2) = 0.82 to 0.96). At higher a(w) values, the rate of inactivation increased and less time was needed to achieve the required population reduction. These results suggest that, to avoid deterioration of product quality, shorter process times at lower temperatures may be used to achieve desired inactivation levels of Salmonella Enteritidis PT 30 by simply increasing the moisture content of almonds. These goals could be achieved with the use of existing procedures already practiced by the food industry, such as washing or prewetting scalding before heat inactivation.
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Affiliation(s)
- Rossana Villa-Rojas
- Departamento de Ingeniería Química, Alimentos y Ambiental, Universidad de las Américas Puebla Santa Catarina Mártir, Cholula, Puebla 72810, Mexico
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Syamaladevi RM, Lu X, Sablani SS, Insan SK, Adhikari A, Killinger K, Rasco B, Dhingra A, Bandyopadhyay A, Annapure U. Inactivation of Escherichia coli Population on Fruit Surfaces Using Ultraviolet-C Light: Influence of Fruit Surface Characteristics. FOOD BIOPROCESS TECH 2012. [DOI: 10.1007/s11947-012-0989-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pleitner A, Zhai Y, Winter R, Ruan L, McMullen LM, Gänzle MG. Compatible solutes contribute to heat resistance and ribosome stability in Escherichia coli AW1.7. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1351-7. [PMID: 22841996 DOI: 10.1016/j.bbapap.2012.07.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/19/2012] [Accepted: 07/19/2012] [Indexed: 11/27/2022]
Abstract
This study investigated the mechanisms of heat resistance in Escherichia coli AW1.7 by quantification of cytoplasmic solutes, determination of ribosome denaturation, and by determination of protein denaturation. To assess the contribution of heat shock proteins and compatible solutes, experiments were conducted after exposure to sublethal heat shock, and with cultures grown at NaCl concentrations ranging from 0 to 6%. Heat resistance of E. coli AW1.7 was compared to the heat sensitive E. coli GGG10 and a plasmid-cured, heat sensitive derivative of E. coli AW1.7 named E. coli AW1.7ΔpHR1. Sublethal heat shock improved survival at 60°C of E. coli GGG10 and AW1.7ΔpHR1 but not of E. coli AW1.7. Addition of NaCl increased the heat resistance of all three strains, but only E. coli AW1.7 exhibited high heat resistance when grown in NaCl concentrations ranging from 2 to 6%. E. coli AW1.7 and GGG10 accumulated 16.1 ± 0.8 and 8.8 ± 0.8mmolL⁻¹ amino acids when grown at 0% NaCl, and 1.47 ± 0.07 and 0.78 ± 0.06mmolL⁻¹ carbohydrates when grown at 6% NaCl, respectively. Ribosome denaturation was determined by differential scanning calorimetry. After growth in the presence of 0% NaCl, the 30S subunit denatured at 63.7 ± 0.8°C and 60.7 ± 0.3°C in E. coli AW1.7 and GGG10, respectively. Fourier-transformed-infrared-spectroscopy did not indicate differences in protein denaturation between the strains during heating. In conclusion, heat resistance in E. coli AW1.7 correlates to ribosome stability at 60°C and is dependent on accumulation of cytoplasmic solutes.
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Affiliation(s)
- Aaron Pleitner
- University of Alberta, Department of Agricultural, Food and Nutritional Science, Edmonton, Canada T6G 2P5
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39
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Monfort S, Ramos S, Meneses N, Knorr D, Raso J, Álvarez I. Design and evaluation of a high hydrostatic pressure combined process for pasteurization of liquid whole egg. INNOV FOOD SCI EMERG 2012. [DOI: 10.1016/j.ifset.2012.01.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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40
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Bermúdez-Aguirre D, Corradini MG. Inactivation kinetics of Salmonella spp. under thermal and emerging treatments: A review. Food Res Int 2012. [DOI: 10.1016/j.foodres.2011.05.040] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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41
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Chmielewski R, Day M, Spatz S, Yu Q, Gast R, Zsak L, Swayne D. Thermal Inactivation of Avian Viral and Bacterial Pathogens in an Effluent Treatment System within a Biosafety Level 2 and 3 Enhanced Facility. APPLIED BIOSAFETY 2011. [DOI: 10.1177/153567601101600402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
| | - Michael Day
- United States Department of Agriculture, Athens, Georgia
| | - Stephen Spatz
- United States Department of Agriculture, Athens, Georgia
| | - Qingzhong Yu
- United States Department of Agriculture, Athens, Georgia
| | - Richard Gast
- United States Department of Agriculture, Athens, Georgia
| | - Laslo Zsak
- United States Department of Agriculture, Athens, Georgia
| | - David Swayne
- United States Department of Agriculture, Athens, Georgia
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42
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Büchner C, Thomas S, Jaros D, Rohm H. Fast-responding thermal-death-time tubes for the determination of thermal bacteria inactivation. Eng Life Sci 2011. [DOI: 10.1002/elsc.201100041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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43
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44
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Chmielewski RA, Beck JR, Swayne DE. Thermal inactivation of avian influenza virus and Newcastle disease virus in a fat-free egg product. J Food Prot 2011; 74:1161-8. [PMID: 21740719 DOI: 10.4315/0362-028x.jfp-10-415] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
High-pathogenicity avian influenza (HPAI) virus, low-pathogenicity avian influenza (LPAI) virus, virulent Newcastle disease virus (vNDV) and low-virulent Newcastle disease virus (lNDV) can be present on the eggshell surface, and HPAI viruses and vNDV can be present in the internal contents of chicken eggs laid by infected hens. With the increase in global trade, egg products could present potential biosecurity problems and affect international trade in liquid and dried egg products. Therefore, the generation of survival curves to determine decimal reduction times (D(T)-values) and change in heat resistance of the viruses (z(D)-value) within fat-free egg product could provide valuable information for development of risk reduction strategies. Thermal inactivation studies using A/chicken/Pennsylvania/1370/83 (H5N2) HPAI virus resulted in D(55)-, D(56)-, D(56.7)-, D(57)-, D(58)-, and D(59)-values of 18.6, 8.5, 3.6, 2.5, 0.4, and 0.4 min, respectively. The z(D)-value was 4.4 °C. LPAI virus A/chicken/New York/13142/94 (H7N2) had D(55)-, D(56.7)-, D(57)-, D(58)-, D(59)-, and D(60)-values of 2.9, 1.4, 0.8, 0.7, 0.7, and 0.5 min, respectively, and a z-value of 0.4 °C. vNDV avian paramyxoviruses of serotype 1 (AMPV-1)/chicken/California/212676/2002 had D(55)-, D(56)-, D(56.7)-, D(57)-, D(58)-, and D(59)-values of 12.4, 9.3, 6.2, 5, 3.7, and 1.7 min, respectively. The z(D)-value was 4.7 °C. lNDV AMPV-1/chicken/United States/B1/1948 had D(55)-, D(57)-, D(58)-, D(59)-, D(61)-, and D(63)-values of 5.3, 2.2, 1.1, 0.55, 0.19, and 0.17 min, respectively, and a z(D)-value of 1.0 °C. Use of these data in developing egg pasteurization standards for AI and NDV-infected countries should allow safer trade in liquid egg products.
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Affiliation(s)
- Revis A Chmielewski
- U.S. Department of Agriculture, Agricultural Research Service, Southeast Poultry Research Laboratory, 934 College Station Road, Athens, Georgia 30605, USA
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Gao M, Tang J, Villa-Rojas R, Wang Y, Wang S. Pasteurization process development for controlling Salmonella in in-shell almonds using radio frequency energy. J FOOD ENG 2011. [DOI: 10.1016/j.jfoodeng.2010.12.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dlusskaya EA, McMullen LM, Gänzle MG. Characterization of an extremely heat-resistant Escherichia coli obtained from a beef processing facility. J Appl Microbiol 2011; 110:840-9. [PMID: 21219555 DOI: 10.1111/j.1365-2672.2011.04943.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIMS This study aimed to determine the survival of Escherichia coli strains during steam and lactic acid decontamination interventions currently used by the beef-processing industry, and to determine their heat resistance. METHODS AND RESULTS Strains were grouped into cocktails of five strains each differing in their RAPD patterns for subsequent identification. Steam and lactic acid treatments on meat reduced cell counts of E. coli strain cocktails by 90-99%. The 20 slaughter plant isolates exhibited only minor variation in their resistance to steam and lactic acid treatments but were more resistant than reference strains (three strains) or isolates from live cattle (seven strains). D(60) values of strains from live cattle, and reference strains ranged from 0·1 to 0·5 min, in keeping with literature data. However, D(60) values of current slaughter plant isolates ranged between 15 for E. coli DM18.3 and 71 min AW 1.7. Cell counts of E. coli AW 1.7 were reduced by <5 log(10) CFU g(-1) in ground beef patties cooked to an internal temperature of 71°C. CONCLUSIONS Strains of E. coli that survive cooking of ground beef to the recommended internal temperature of 71°C can be isolated from beef-processing facilities. SIGNIFICANCE AND IMPACT OF THE STUDY Pathogen interventions in current commercial beef slaughter may select for extremely heat-resistant strains of E. coli.
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Affiliation(s)
- E A Dlusskaya
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
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de Lamo-Castellví S, Ratphitagsanti W, Balasubramaniam VM, Yousef AE. Inactivation of Bacillus amyloliquefaciens spores by a combination of sucrose laurate and pressure-assisted thermal processing. J Food Prot 2010; 73:2043-52. [PMID: 21219716 DOI: 10.4315/0362-028x-73.11.2043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this research was to study the effect of sucrose laurate ester (SL) on enhancing pressure-assisted thermal processing (PATP) inactivation of Bacillus amyloliquefaciens Fad 82 spores. B. amyloliquefaciens spores (∼10⁸ CFU/ml) were suspended in deionized water, solutions of 0.1, 0.5, and 1.0% SL, and mashed carrots without or with 1% SL. Samples were treated at 700 MPa and 105°C for 0 (come-up time), 1, 2, and 5 min and analyzed by pour-plating and most-probable-number techniques. Heat shock (80°C, 10 min) was applied to untreated and treated samples to study the germination rates. Results were also compared against samples treated by high pressure processing (700 MPa, 35°C) and thermal processing (105°C, 0.1 MPa). Among the combinations tested, SL at concentrations of 1.0% showed the best synergistic effect against spores of B. amyloliquefaciens when combined with PATP treatments. In the case of high pressure and thermal processing treatments, SL did not enhance spore inactivation at the conditions tested. These results suggest that SL is a promising antimicrobial compound that can help reduce the severity of PATP treatments.
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Affiliation(s)
- S de Lamo-Castellví
- Departament d'Enginyeria Química, Universitat Rovira I Virgili, Av. Dels Països Catalans, Spain.
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Ratphitagsanti W, De Lamo-Castellvi S, Balasubramaniam V, Yousef AE. Efficacy of Pressure-Assisted Thermal Processing, in Combination with Organic Acids, againstâBacillus amyloliquefaciensâSpores Suspended in Deionized Water and Carrot Puree. J Food Sci 2010; 75:M46-52. [DOI: 10.1111/j.1750-3841.2009.01450.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Comparison of aluminum thermal-death-time disks with a pilot-scale pasteurizer on the thermal inactivation of Escherichia coli K12 in apple cider. Food Control 2009. [DOI: 10.1016/j.foodcont.2008.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Gurtler J, Kornacki J. Comparison of supplements to enhance recovery of heat-injuredSalmonellafrom egg albumen. Lett Appl Microbiol 2009; 49:503-9. [DOI: 10.1111/j.1472-765x.2009.02695.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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