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Koutsoumanis K, Allende A, Bolton D, Bover‐Cid S, Chemaly M, Herman L, Hilbert F, Lindqvist R, Nauta M, Nonno R, Peixe L, Skandamis P, Ru G, Simmons M, De Cesare A, Escamez PF, Suffredini E, Ortiz‐Pelaez A, Ordonez AA. Evaluation of alternative methods of tunnel composting (submitted by the European Composting Network) II. EFSA J 2024; 22:e8745. [PMID: 38681740 PMCID: PMC11046411 DOI: 10.2903/j.efsa.2024.8745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024] Open
Abstract
Two alternative methods for producing compost in a tunnel, from certain category (Cat.) 3 animal by-products (ABP) and other non-ABP material, were assessed. The first method proposed a minimum temperature of 55°C for 72 h and the second 60°C for 48 h, both with a maximum particle size of 200 mm. The assessment of the Panel on Biological Hazards (BIOHAZ) exclusively focused on Cat. 3 ABP materials (catering waste and processed foodstuffs of animal origin no longer intended for human consumption). The proposed composting processes were evaluated for their efficacy to achieve a reduction of at least 5 log10 of Enterococcus faecalis and Salmonella Senftenberg (775W, H2S negative) and at least 3 log10 of relevant thermoresistant viruses. The applicant provided a list of biological hazards that may enter the composting process and selected parvoviruses as the indicator of the thermoresistant viruses. The evidence provided by the applicant included: (a) literature data on thermal inactivation of biological hazards; (b) results from validation studies on the reduction of E. faecalis, Salmonella Senftenberg 775W H2S negative and canine parvovirus carried out in composting plants across Europe; (c) and experimental data from direct measurements of reduction of infectivity of murine parvovirus in compost material applying the time/temperature conditions of the two alternative methods. The evidence provided showed the capacity of the proposed alternative methods to reduce E. faecalis and Salmonella Senftenberg 775W H2S negative by at least 5 log10, and parvoviruses by at least 3 log10. The BIOHAZ Panel concluded that the two alternative methods under assessment can be considered to be equivalent to the processing method currently approved in the Commission Regulation (EU) No 142/2011.
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Hansen TB, Abdalas S, Al-Hilali I, Hansen LT. Predicting the effect of salt on heat tolerance of Listeria monocytogenes in meat and fish products. Int J Food Microbiol 2021; 352:109265. [PMID: 34116257 DOI: 10.1016/j.ijfoodmicro.2021.109265] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 01/22/2021] [Accepted: 05/23/2021] [Indexed: 10/21/2022]
Abstract
Listeria monocytogenes is a potentially fatal foodborne pathogen that can be found in various ready-to-eat (RTE) products. It tolerates adverse conditions such as high salt concentrations and refrigerated storage, thus, the elimination of the pathogen in food processing often relies on heat processing. The objective of this study was to create a model to predict the effect of salt on heat tolerance of L. monocytogenes in meat and seafood products during heat treatments conducted at 57 to 65 °C to reduce numbers by ≥3 log10 cycles. Salt concentrations, up to 6% in the water phase (WPS%), were applied to cover a variety of lightly salted RTE meat and seafood products. The experimental work involved samples of ground pork tenderloin, ground chicken breast fillet and skinned, ground salmon fillet adjusted to different WPS% i.e., 3.6 and 5.2 WPS% for pork samples, 2.0, 3.0, 3.5 and 6.0 WPS% for chicken samples and 3.0 and 6.0 WPS% for salmon samples. All samples were inoculated with late-stationary phase L. monocytogenes cultures. For pork samples, a two-strain mixture of a pork isolate (MS22254) and an environmental isolate (MS22246) was applied. For chicken and salmon samples, a seafood isolate (MS22258) and isolate MS22246 was applied as single cultures. Samples were vacuum-packed in sterile bags, immerged in water bath, and held at constant temperatures of 57, 60 and 65 °C for pork samples and 58, 61 and 62.5 °C for chicken and salmon samples. For survivor curves, where at least 3 log10-reduction were obtained, heat tolerance was expressed as decimal reduction times, D-values. D-values were observed to increase with increasing WPS%. The effect of salt on heat tolerance of L. monocytogenes was defined as the relative increase (RI-value) in D-value obtained when salt had been added to the food. The effect of WPS% on RI-values was independent of heating temperatures, foods and strains. For secondary modelling, RI-values were transformed using the natural logarithm, ln(RI) and fitted to a linear model as a function of WPS%. Model validation, with 56 independent values collected from the scientific literature, resulted in bias and accuracy factors of 0.89 and 1.26, respectively, suggesting acceptable performance with tendency to slightly under-predict. The developed predictive model can be used to guide the design of heat processes for manufacturers of lightly preserved and mildly processed meat and seafood products requiring more than 3 log10 reduction of L. monocytogenes to ensure safety.
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Affiliation(s)
- Tina Beck Hansen
- The National Food Institute, Technical University of Denmark, Division for Microbiology and Production, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark.
| | - Somaya Abdalas
- The National Food Institute, Technical University of Denmark, Division for Microbiology and Production, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
| | - Iman Al-Hilali
- The National Food Institute, Technical University of Denmark, Division for Microbiology and Production, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
| | - Lisbeth Truelstrup Hansen
- The National Food Institute, Technical University of Denmark, Division for Microbiology and Production, Kemitorvet, Building 202, DK-2800 Kgs. Lyngby, Denmark
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Koutsoumanis K, Allende A, Bolton DJ, Bover‐Cid S, Chemaly M, Davies R, De Cesare A, Herman LM, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Escámez PF, Ortiz‐Peláez A, Ashe S, Alvarez‐Ordóñez A. Evaluation of Alternative Methods of Tunnel Composting (submitted by the European Composting Network). EFSA J 2020; 18:e06226. [PMID: 32774510 PMCID: PMC7404150 DOI: 10.2903/j.efsa.2020.6226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Two alternative methods for the production of compost from certain category 3 animal by-products (catering waste and processed foodstuffs of animal origin) were assessed. The first proposed a minimum temperature of 55°C for 72 h; the second 60°C for 48 h, each with a maximum particle size of 200 mm. The proposed composting processes were assessed by the BIOHAZ Panel for their efficacy to achieve a reduction of 5 log10 of Enterococcus faecalis or Salmonella Senftenberg (775W, H2S negative) and a 3 log10 reduction of the infectivity titre of thermoresistant viruses, such as parvovirus, in the composted material, as set out in Annex V, Chapter 3, Section 2 of Commission Regulation (EU) No 142/2011. The assessment of the BIOHAZ Panel exclusively focused on the ABP raw materials (catering waste and processed foodstuffs) intended for human consumption. The applicant did not provide any validation experiments with direct measurement of the reduction of viability of endogenous indicators or spiked surrogate bacteria. However, from thermal inactivation parameters reported in the literature, it can be concluded that the proposed composting standards can achieve at least a 5 log10 reduction of Enterococcus faecalis or Salmonella Senftenberg 775W. The applicant did not consider thermoresistant viruses as a relevant hazard and therefore did not provide any data from direct measurements of the reduction of infectivity of spiked thermoresistant viruses, nor provide data from validation studies undertaken at national level or data from literature supporting the efficacy of the proposed composting standards on thermoresistant viruses. However, thermoresistant viruses should be considered to be a relevant hazard in this context and validation data should have been provided accordingly. The BIOHAZ Panel considers that the evidence provided by the applicant does not demonstrate that the requirements of Annex V, Chapter 3, Section 2 of Commission Regulation (EU) No 142/2011 are achieved.
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Felício MTS, Ramalheira R, Ferreira V, Brandão T, Silva J, Hogg T, Teixeira P. Thermal inactivation of Listeria monocytogenes from alheiras, traditional Portuguese sausage during cooking. Food Control 2011. [DOI: 10.1016/j.foodcont.2011.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Halder A, Black DG, Davidson PM, Datta A. Development of associations and kinetic models for microbiological data to be used in comprehensive food safety prediction software. J Food Sci 2011; 75:R107-20. [PMID: 20722946 DOI: 10.1111/j.1750-3841.2010.01687.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The objective of this study was to use an existing database of food products and their associated processes, link it with a list of the foodborne pathogenic microorganisms associated with those products and finally identify growth and inactivation kinetic parameters associated with those pathogens. The database was to be used as a part of the development of comprehensive software which could predict food safety and quality for any food product. The main issues in building such a predictive system included selection of predictive models, associations of different food types with pathogens (as determined from outbreak histories), and variability in data from different experiments. More than 1000 data sets from published literature were analyzed and grouped according to microorganisms and food types. Final grouping of data consisted of the 8 most prevalent pathogens for 14 different food groups, covering all of the foods (>7000) listed in the USDA Natl. Nutrient Database. Data for each group were analyzed in terms of 1st-order inactivation, 1st-order growth, and sigmoidal growth models, and their kinetic response for growth and inactivation as a function of temperature were reported. Means and 95% confidence intervals were calculated for prediction equations. The primary advantage in obtaining group-specific kinetic data is the ability to extend microbiological growth and death simulation to a large array of product and process possibilities, while still being reasonably accurate. Such simulation capability could provide vital ''what if'' scenarios for industry, Extension, and academia in food safety.
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Affiliation(s)
- Amit Halder
- Biological and Environmental Engineering, Cornell Univ., Ithaca, NY 14853, USA
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6
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Jørgensen F, Stephens P, Knøchel S. The effect of osmotic shock and subsequent adaptation on the thermotolerance and cell morphology ofListeria monocytogenes. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1365-2672.1995.tb03137.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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Microbial heat resistance of Listeria monocytogenes and the impact on ready-to-eat meat quality after post-package pasteurization. Meat Sci 2006; 74:425-34. [DOI: 10.1016/j.meatsci.2006.02.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Revised: 02/28/2006] [Accepted: 02/28/2006] [Indexed: 11/15/2022]
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8
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Murphy RY, Beard BL, Martin EM, Duncan LK, Marcy JA. Comparative Study of Thermal Inactivation of Escherichia coli
O157:H7, Salmonella
, and Listeria monocytogenes
in Ground Pork. J Food Sci 2006. [DOI: 10.1111/j.1365-2621.2004.tb06351.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Murphy R, Beard B, Martin E, Keener A, Osaili T. Predicting process lethality of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in ground, formulated, and formed beef/turkey links cooked in an air impingement oven. Food Microbiol 2004. [DOI: 10.1016/j.fm.2004.01.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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10
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Murphy RY, Martin EM, Duncan LK, Beard BL, Marcy JA. Thermal process validation for Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in ground turkey and beef products. J Food Prot 2004; 67:1394-402. [PMID: 15270492 DOI: 10.4315/0362-028x-67.7.1394] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
At 55 to 70 degrees C, thermal inactivation D-values for Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes were 19.05 to 0.038, 43.10 to 0.096, and 33.11 to 0.12 min, respectively, in ground turkey and 21.55 to 0.055, 37.04 to 0.066, and 36.90 to 0.063 min, respectively, in ground beef. The z-values were 5.73, 5.54, and 6.13 degrees C, respectively, in ground turkey and 5.43, 5.74, and 6.01 degrees C, respectively, in ground beef. In both ground turkey and beef, significant (P < 0.05) differences were found in the D-values between E. coli O157:H7 and Salmonella or between E. coli O157:H7 and L. monocytogenes. At 65 to 70 degrees C, D-values for E. coli O157:H7, Salmonella, and L. monocytogenes were also significantly (P < 0.05) different between turkey and beef. The obtained D- and z-values were used in predicting process lethality of the pathogens in ground turkey and beef patties cooked in an air impingement oven and confirmed by inoculation studies for a 7-log (CFU/g) reduction of E. coli O157:H7, Salmonella, and L. monocytogenes.
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Affiliation(s)
- R Y Murphy
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA.
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11
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Juneja VK, Marks HM. Mathematical description of non-linear survival curves of Listeria monocytogenes as determined in a beef gravy model system at 57.5 to 65 °C. INNOV FOOD SCI EMERG 2003. [DOI: 10.1016/s1466-8564(03)00025-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Lihono MA, Mendonca AF, Dickson JS, Dixon PM. A predictive model to determine the effects of temperature, sodium pyrophosphate, and sodium chloride on thermal inactivation of starved Listeria monocytogenes in pork slurry. J Food Prot 2003; 66:1216-21. [PMID: 12870755 DOI: 10.4315/0362-028x-66.7.1216] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effects and interactions of 27 combinations of heating temperature (57.5 to 62.5 degrees 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 degrees 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.
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Affiliation(s)
- M A Lihono
- Department of Food Science and Human Nutrition, Iowa State University, 2312 Food Sciences Building, Ames, Iowa 50011, USA
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13
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Juneja VK. Predictive model for the combined effect of temperature, sodium lactate, and sodium diacetate on the heat resistance of Listeria monocytogenes in beef. J Food Prot 2003; 66:804-11. [PMID: 12747689 DOI: 10.4315/0362-028x-66.5.804] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effects of heating temperature (60 to 73.9 degrees C), sodium lactate (NaL; 0.0 to 4.8% [wt/wt]), and/or sodium diacetate (SDA; 0.0 to 0.25% [wt/wt]) and of the interactions of these factors on the heat resistance of a five-strain mixture of Listeria monocytogenes in 75% lean ground beef were examined. Thermal death times for L. monocytogenes in filtered stomacher bags in a circulating water bath were determined. The recovery medium was tryptic soy agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. Decimal reduction times (D-values) were calculated by fitting a survival model to the data with a curve-fitting program. The D-values were analyzed by second-order response surface regression for temperature, NaL level, and SDA level. The D-values observed for beef with no NaL or SDA at 60, 65, 71.1, and 73.9 degrees C were 4.67, 0.72, 0.17, and 0.04 min, respectively. The addition of 4.8% NaL to beef increased heat resistance at all temperatures, with D-values ranging from 14.3 min at 60 degrees C to 0.13 min at 73.9 degrees C. Sodium diacetate interacted with NaL, thereby reducing the protective effect of NaL and rendering L. monocytogenes in beef less resistant to heat. A mathematical model describing the combined effect of temperature, NaL level, and SDA level on the thermal inactivation of L. monocytogenes was developed. This model can predict D-values for any combination of temperature, NaL level, and SDA level that is within the range of those tested. This predictive model will have substantial practical importance to processors of cooked meat, allowing them to vary their thermal treatments of ready-to-eat meat products in a safe manner.
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Affiliation(s)
- Vijay K Juneja
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA.
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14
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Passos MHC, Kuaye AY. Influence of the formulation, cooking time and final internal temperature of beef hamburgers on the destruction of Listeria monocytogenes. Food Control 2002. [DOI: 10.1016/s0956-7135(01)00080-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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15
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Influence of sodium pyrophosphate on thermal inactivation of Listeria monocytogenes in pork slurry and ground pork. Food Microbiol 2001. [DOI: 10.1006/fmic.2001.0398] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Chikthimmah N, Guyer RB, Knabel SJ. Validation of a 5-log10 reduction of Listeria monocytogenes following simulated commercial processing of Lebanon bologna in a model system. J Food Prot 2001; 64:873-6. [PMID: 11403142 DOI: 10.4315/0362-028x-64.6.873] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recently, numerous product recalls and one devastating outbreak that claimed 21 lives were attributed to Listeria monocytogenes in ready-to-eat meat products. Consequently, the Food Safety and Inspection Service published a federal register notice requiring manufacturers of ready-to-eat meat and poultry products to reassess their hazard analysis and critical control point plans for these products as specified in 9 CFR 417.4(a). Lebanon bologna is a moist, fermented ready-to-eat sausage. Because of undesirable quality changes. Lebanon bologna is often not processed above 48.9 degrees C (120 degrees F). Therefore, the present research was conducted to validate the destruction of L. monocytogenes in Lebanon bologna batter in a model system. During production, fermentation of Lebanon bologna to pH 4.7 alone significantly reduced L. monocytogenes by 2.3 log10 CFU/g of the sausage mix (P < 0.01). Heating the fermented mix to 48.9 degrees C in 10.5 h destroyed at least 7.0 log10 CFU of L. monocytogenes per g of sausage mix. A combination of low pH (5.0 or lower) and high heating temperatures (> or =43.3 degrees C, 115 degrees F) destroyed more than 5 log10 CFU of L. monocytogenes per g of sausage mix during the processing of Lebanon bologna. In conclusion, an existing commercial process, which was validated for destruction of Escherichia coli O157:H7, was also effective for the destruction of more than 5 log10 CFU of L. monocytogenes.
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Affiliation(s)
- N Chikthimmah
- Department of Food Science, The Pennsylvania State University, University Park 16802, USA
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17
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Abstract
The heat resistance data on Listeria monocytogenes in culture media and foods are summarized. Most heat resistance data for foods have been obtained in dairy, meat, poultry, and egg products. Limited data have been published on seafood, fruits, and vegetables. The methodologies employed have evolved over time; hence data from earlier experiments are not directly comparable to more recent studies. Many factors influence the heat resistance of L. monocytogenes. Variation exists among different strains in their ability to withstand heat treatment. In addition, heat resistance is influenced by age of the culture, growth conditions, recovery media, and characteristics of foods such as salt content, a(w), acidity, and the presence of other inhibitors. Listeriae are more heat resistant than most other nonspore-forming foodborne pathogens, and thus, processing recommendations based on data from experiments with Salmonella spp. or pathogenic Escherichia coli may not be sufficient to eliminate similar numbers of L. monocytogenes. The data provided in this review may prove useful for food processors in determining appropriate times and temperatures for producing foods free of vegetative pathogens.
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Affiliation(s)
- M E Doyle
- Food Research Institute, University of Wisconsin, Madison 53706, USA
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18
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Mazzotta AS, Gombas DE. Heat resistance of an outbreak strain of Listeria monocytogenes in hot dog batter. J Food Prot 2001; 64:321-4. [PMID: 11252474 DOI: 10.4315/0362-028x-64.3.321] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The heat resistance of a strain of Listeria monocytogenes responsible for a listeriosis outbreak in hot dogs was not higher than the heat resistance of other L. monocytogenes strains when tested in tryptic soy broth and in laboratory-prepared hot dog batter. For the thermal death time experiments, the cells were grown to stationary phase or were starved in phosphate-buffered saline, pH 7, for 6 h at 30 degrees C. Starvation increased the heat resistance of L. monocytogenes in broth but not in hot dog batter. D-values in hot dog batter were higher than in broth. For the hot dog formulation used in this study, cooking the hot dog batter for 30 s at 71.1 degrees C (160 degrees F), or its equivalent using a z-value of 6 degrees C (11 degrees F), would inactivate 5 logs of L. monocytogenes.
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Affiliation(s)
- A S Mazzotta
- Center for the Development of Research Policy and New Technologies, National Food Processors Association, Washington, DC 20005, USA
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19
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Modi KD, Chikindas ML, Montville TJ. Sensitivity of nisin-resistant Listeria monocytogenes to heat and the synergistic action of heat and nisin. Lett Appl Microbiol 2000; 30:249-53. [PMID: 10747260 DOI: 10.1046/j.1472-765x.2000.00708.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nisin, a bacteriocin produced by some strains of Lactococcus lactis, acts against foodborne pathogen Listeria monocytogenes. A single exposure of cells to nisin can generate nisin-resistant (Nisr) mutants, which may compromise the use of nisin in the food industry. The objective of this research was to compare the heat resistance of Nisr and wild type (WT) Listeria monocytogenes. The synergistic effect of heat-treatment (55 degrees C) and nisin (500 IU ml-1) on the Nisr cells and the WT L. monocytogenes Scott A was also studied. When the cells were grown in the absence of nisin, there was no significant (alpha = 0.05) difference in heat resistance between WT and Nisr cells of L. monocytogenes at 55, 60 and 65 degrees C. However, when the Nisr cells were grown in the presence of nisin, they were more sensitive to heat at 55 degrees C than the WT cells. The D-values at 55 degrees C were 2.88 and 2.77 min for Nisr ATCC 700301 and ATCC 700302, respectively, which was significantly (alpha = 0.05) lower than the D-value for WT, 3.72 min. When Nisr cells were subjected to a combined treatment of heat and nisin, there was approximately a four log reduction during the first 7 min of treatment.
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Affiliation(s)
- K D Modi
- Graduate Program in Microbiology and Molecular Genentics and Department of Food Science, New Jersey Agricultural Experiment Station, Cook College; Rutgers, The State University of New Jersey, New Brunswick, NJ 08901-8520, USA
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20
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DOHERTY ALICEM, McMAHON CAROLM, SHERIDAN J, BLAIR I, McDOWELL D, HEGARTY T. THERMAL RESISTANCE OF YERSINIA ENTEROCOLITICA AND LISTERIA MONOCYTOGENES IN MEAT AND POTATO SUBSTRATES. J Food Saf 1998. [DOI: 10.1111/j.1745-4565.1998.tb00204.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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ROERING ANNM, WIERZBA RACHELK, IHNOT ANNEM, LUCHANSKY JOHNB. PASTEURIZATION OF VACUUM-SEALED PACKAGES OF SUMMER SAUSAGE INOCULATED WITH LISTERIA MONOCYTOGENES. J Food Saf 1998. [DOI: 10.1111/j.1745-4565.1998.tb00201.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Lim CH, Flint KP. The recovery of heat-stressed Escherichia coli in lake water microcosms. Lett Appl Microbiol 1995; 21:364-7. [PMID: 8554763 DOI: 10.1111/j.1472-765x.1995.tb01082.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Escherichia coli was heat stressed at 55 degrees, 60 degrees or 65 degrees C in sterile flasks of lake water. After 6 h at these temperatures the viable count on nutrient agar had dropped below the limits of detection (1 colony in 100 ml). The flasks were transferred to a 15 degrees C incubator and left for 7 d. Recovery of the stressed E. coli was shown to occur within 48 h at this temperature. Recovery also occurred in microcosms amended with 5% (v/v) synthetic sewage. The stressed E. coli multiplied in the amended but not in the unamended microcosms.
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Affiliation(s)
- C H Lim
- Department of Biological Sciences, University of Warwick, Coventry, UK
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Miles CA, Mackey BM. A mathematical analysis of microbial inactivation at linearly rising temperatures: calculation of the temperature rise needed to kill Listeria monocytogenes in different foods and methods for dynamic measurements of D and z values. THE JOURNAL OF APPLIED BACTERIOLOGY 1994; 77:14-20. [PMID: 7928779 DOI: 10.1111/j.1365-2672.1994.tb03038.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
From a theoretical analysis of the inactivation of microbes heated at linearly rising temperatures an equation was derived for predicting the linear temperature rise needed to reduce viable numbers of microbes by any chosen factor. This equation is used to predict the temperatures needed to inactivate Listeria monocytogenes in different foods based on published D and z values. Two novel mathematical methods for deriving D and z values from viable counts obtained at linearly rising temperatures are also presented.
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Affiliation(s)
- C A Miles
- Department of Veterinary Medicine, University of Bristol, UK
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Ben Embarek PK, Huss HH. Heat resistance of Listeria monocytogenes in vacuum packaged pasteurized fish fillets. Int J Food Microbiol 1993; 20:85-95. [PMID: 8268058 DOI: 10.1016/0168-1605(93)90096-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The heat resistance of two strains of Listeria monocytogenes in sous-vide cooked fillets of cod and salmon was investigated. Fish sticks of 5 g were inoculated, vacuum-packed and heated at different combinations of time and temperature (58-80 degrees C). Time-temperature combinations allowing survival and time-temperature combinations at which the bacteria were destroyed, were used to determine D- and z-values. D-values were in the range of what has been published for other food products. D60-values were between 1.95 and 4.48 min depending on the strain and the fish. Both strains were one-four-times more heat resistant in salmon than in cod, showing the importance of the heating menstruum. This difference may be due to the higher fat content in salmon as compared to cod. Z-values were calculated to be 5.65 and 6.4 degrees C, respectively, for the two strains. The suitability of methods for heat resistance experiments and the survival of L. monocytogenes in sous-vide cooked fish fillets are discussed.
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Affiliation(s)
- P K Ben Embarek
- Technological Laboratory, Danish Ministry of Fisheries, Technical University, Lyngby
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Fairchild TM, Foegeding PM. A proposed nonpathogenic biological indicator for thermal inactivation of Listeria monocytogenes. Appl Environ Microbiol 1993; 59:1247-50. [PMID: 8489233 PMCID: PMC202269 DOI: 10.1128/aem.59.4.1247-1250.1993] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Listeria innocua M1 was developed as a thermal processing indicator organism for L. monocytogenes by selection of a rifampin- and streptomycin-resistant mutant. zetaD values were 5.6 and 5.8 degrees C, and D (68 degrees C) values were 3.8 and 4.9 s for L. monocytogenes and L. innocua, respectively, in skim milk. The advantages of easy selection, similar heat resistance, and nonpathogenicity make L. innocua M1 appropriate for challenge studies designed to evaluate process lethality with respect to L. monocytogenes.
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Affiliation(s)
- T M Fairchild
- Department of Food Science, North Carolina State University, Box 7624, Raleigh 27695-7624
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Sörqvist S. Heat resistance of Listeria monocytogenes by two recovery media used with and without cold preincubation. THE JOURNAL OF APPLIED BACTERIOLOGY 1993; 74:428-32. [PMID: 8486551 DOI: 10.1111/j.1365-2672.1993.tb05150.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Three strains of Listeria monocytogenes were heat-treated at three temperatures in physiological saline by a capillary tube method. Recovery of heat-treated bacteria was performed on blood agar and on tryptose phosphate agar with ferric citrate and aesculin (TPA-FE). Both media were used in two ways: (1) incubation at 37 degrees C for 7 d, and (2) preincubation at 4 degrees C for 5 d in order to obtain repair of heat-injured bacteria, followed by incubation at 37 degrees C for 7 d. D and z values were determined. In both incubation procedures, better average recovery was obtained on blood agar than on TPA-FE. Thus, higher D values were recorded when blood agar was used. In most cases the differences were statistically significant. Repair at 4 degrees C of heat-injured bacteria occurred on both media but the proportions of repaired bacteria were higher on blood agar. The repair on this medium was generally reflected in higher D values for preincubated samples. Some significant differences in heat resistance were noted between the strains.
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Affiliation(s)
- S Sörqvist
- Department of Food Hygiene, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala
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