1
|
Wedel C, Wenning M, Dettling A, Scherer S, Hinrichs J. Resistance of thermophilic spore formers isolated from milk and whey products towards cleaning-in-place conditions: Influence of pH, temperature and milk residues. Food Microbiol 2019; 83:150-158. [DOI: 10.1016/j.fm.2019.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/29/2019] [Accepted: 05/04/2019] [Indexed: 01/04/2023]
|
2
|
Heat resistance of spores of 18 strains of Geobacillus stearothermophilus and impact of culturing conditions. Int J Food Microbiol 2019; 291:161-172. [DOI: 10.1016/j.ijfoodmicro.2018.11.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 10/14/2018] [Accepted: 11/06/2018] [Indexed: 11/24/2022]
|
3
|
Investigating the influence of pH and selected heating media on thermal destruction kinetics of Geobacillus stearothermophilus (ATCC10149). JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2019. [DOI: 10.1007/s11694-019-00046-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
4
|
Gómez-Jódar I, Ros-Chumillas M, Palop A. Effect of heating rate on highly heat-resistant spore-forming microorganisms. FOOD SCI TECHNOL INT 2015; 22:164-72. [PMID: 25852134 DOI: 10.1177/1082013215580494] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/05/2015] [Indexed: 11/16/2022]
Abstract
Highly heat-resistant spore-forming Bacillus cause nonsterility problems in canned food and reduce the shelf life of many processed foods. The aim of this research was to evaluate the thermal inactivation of Bacillus sporothermodurans IIC65, Bacillus subtilis IC9, and Geobacillus stearothermophilus T26 under isothermal and nonisothermal conditions. The data obtained showed that B. sporothermodurans and B. subtilis were more heat resistant than G. stearothermophilus. The survival curves of B. sporothermodurans and B. subtilis showed shoulders, while the survival curves of G. stearothermophilus showed tails. Under nonisothermal treatment, at heating rates of 1 and 20 ℃/min, time needed to completely inactivate G. stearothermophilus was shorter than that required for B. sporothermodurans and B. subtilis. In complex heat treatments (heating-holding-cooling), the survival curves of B. sporothermodurans and B. subtilis showed the same activation shoulders than those obtained under isothermal treatments and the activation shoulders were again absent in the case of G. stearothermophilus. Predictions fitted quite well the data obtained for B. sporothermodurans. In contrast, the data for B. subtilis showed half a log cycle more survival than expected and in the case of G. stearothermophilus, the survival curve obtained showed much higher inactivation than expected.
Collapse
Affiliation(s)
- Isabel Gómez-Jódar
- Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain
| | - María Ros-Chumillas
- Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain
| | - Alfredo Palop
- Dpto. Ingeniería de Alimentos y del Equipamiento Agrícola, Campus de Excelencia Internacional Regional "Campus Mare Nostrum", Universidad Politécnica de Cartagena, Cartagena, Spain
| |
Collapse
|
5
|
|
6
|
Rigaux C, Denis JB, Albert I, Carlin F. A meta-analysis accounting for sources of variability to estimate heat resistance reference parameters of bacteria using hierarchical Bayesian modeling: Estimation of D at 121.1 °C and pH 7, zT and zpH of Geobacillus stearothermophilus. Int J Food Microbiol 2012; 161:112-20. [PMID: 23279820 DOI: 10.1016/j.ijfoodmicro.2012.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 10/01/2012] [Accepted: 12/02/2012] [Indexed: 11/16/2022]
Abstract
Predicting microbial survival requires reference parameters for each micro-organism of concern. When data are abundant and publicly available, a meta-analysis is a useful approach for assessment of these parameters, which can be performed with hierarchical Bayesian modeling. Geobacillus stearothermophilus is a major agent of microbial spoilage of canned foods and is therefore a persistent problem in the food industry. The thermal inactivation parameters of G. stearothermophilus (D(ref), i.e.the decimal reduction time D at the reference temperature 121.1°C and pH 7.0, z(T) and z(pH)) were estimated from a large set of 430 D values mainly collected from scientific literature. Between-study variability hypotheses on the inactivation parameters D(ref), z(T) and z(pH) were explored, using three different hierarchical Bayesian models. Parameter estimations were made using Bayesian inference and the models were compared with a graphical and a Bayesian criterion. Results show the necessity to account for random effects associated with between-study variability. Assuming variability on D(ref), z(T) and z(pH), the resulting distributions for D(ref), z(T) and z(pH) led to a mean of 3.3 min for D(ref) (95% Credible Interval CI=[0.8; 9.6]), to a mean of 9.1°C for z(T) (CI=[5.4; 13.1]) and to a mean of 4.3 pH units for z(pH) (CI=[2.9; 6.3]), in the range pH 3 to pH 7.5. Results are also given separating variability and uncertainty in these distributions, as well as adjusted parametric distributions to facilitate further use of these results in aqueous canned foods such as canned vegetables.
Collapse
Affiliation(s)
- Clémence Rigaux
- INRA, UR 1204, Met@risk, Food Risk Analysis Methodologies, F-75005 Paris, France.
| | | | | | | |
Collapse
|
7
|
|
8
|
Shen C, Geornaras I, Kendall PA, Sofos JN. Antilisterial activities of salad dressings, without or with prior microwave oven heating, on frankfurters during simulated home storage. Int J Food Microbiol 2009; 132:9-13. [DOI: 10.1016/j.ijfoodmicro.2009.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 03/12/2009] [Accepted: 03/13/2009] [Indexed: 12/01/2022]
|
9
|
Iciek J, Błaszczyk I, Papiewska A. The effect of organic acid type on thermal inactivation of Geobacillus stearothermophilus spores. J FOOD ENG 2008. [DOI: 10.1016/j.jfoodeng.2007.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
10
|
Head D, Cenkowski S, Holley R, Blank G. Effects of superheated steam on Geobacillus stearothermophilus spore viability. J Appl Microbiol 2008; 104:1213-20. [DOI: 10.1111/j.1365-2672.2007.03647.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
11
|
CUNNINGHAM S, MAGEE T, MCMINN W, GAZE J, RICHARDSON P. THERMAL RESISTANCE OF BACILLUS STEAROTHERMOPHILUS SPORES IN DRIED PASTA AT DIFFERENT STAGES OF REHYDRATION. J FOOD PROCESS PRES 2007. [DOI: 10.1111/j.1745-4549.2007.00138.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
12
|
Junker B, Lester M, Brix T, Wong D, Nuechterlein J. A next generation, pilot-scale continuous sterilization system for fermentation media. Bioprocess Biosyst Eng 2006; 28:351-78. [PMID: 16496186 PMCID: PMC1705532 DOI: 10.1007/s00449-005-0041-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Accepted: 12/12/2005] [Indexed: 11/01/2022]
Abstract
A new continuous sterilization system was designed, constructed, started up, and qualified for media sterilization for secondary metabolite cultivations, bioconversions, and enzyme production. An existing Honeywell Total Distributed Control 3000-based control system was extended using redundant High performance Process Manager controllers for 98 I/O (input/output) points. This new equipment was retrofitted into an industrial research fermentation pilot plant, designed and constructed in the early 1980s. Design strategies of this new continuous sterilizer system and the expanded control system are described and compared with the literature (including dairy and bio-waste inactivation applications) and the weaknesses of the prior installation for expected effectiveness. In addition, the reasoning behind selection of some of these improved features has been incorporated. Examples of enhancements adopted include sanitary heat exchanger (HEX) design, incorporation of a "flash" cooling HEX, on-line calculation of F(o) and R(o), and use of field I/O modules located near the vessel to permit low-cost addition of new instrumentation. Sterilizer performance also was characterized over the expected range of operating conditions. Differences between design and observed temperature, pressure, and other profiles were quantified and investigated.
Collapse
Affiliation(s)
- B Junker
- Bioprocess Research and Development, Merck Research Laboratories, RY810-127, P. O. Box 2000, Rahway, NJ 07065, USA.
| | | | | | | | | |
Collapse
|
13
|
Abstract
Microorganisms have successfully adapted to changes in food production, processing, and preservation techniques, resulting in a number of new and emerging foodborne pathogens and the re-emergence of organisms that have been problematic in the past. To protect public health, science must meet the challenges that result from the remarkable adaptability of foodborne pathogens. However, not all of the challenges of preventing foodborne illness reside in the realm of science. Food safety policy must evolve in response to new scientific understanding of hazards in the food supply and an ever-changing food processing industry. The laws, regulations, and organizations comprising the food safety system frequently lag behind current scientific knowledge of the risks posed by foodborne pathogens. Future systemic changes to enhance food safety will require better understanding of risks associated with specific pathogens occurring in the food supply and the costs and benefits of implementing mitigation strategies.
Collapse
|
14
|
Serp D, von Stockar U, Marison IW. Immobilized bacterial spores for use as bioindicators in the validation of thermal sterilization processes. J Food Prot 2002; 65:1134-41. [PMID: 12117247 DOI: 10.4315/0362-028x-65.7.1134] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Spores of Bacillus subtilis ATCC 6051 and Bacillus stearothermophilus NCTC 10003 were immobilized in monodisperse alginate beads (diameter, 550 microm +/- 5%), and the capacity of the immobilized bioindicators to provide accurate and reliable F-values for sterilization processes was studied. The resistance of the beads to abrasion and heat was strong enough to ensure total retention of the bioindicators in the beads in a sterilization cycle. D- and z-values for free spores were identical to those for immobilized spores, which shows that immobilization does not modify the thermal resistance of the bioindicators. A D(100 degrees C) value of 1.5 min was found for free and immobilized B. subtilis spores heated in demineralized water, skimmed milk, and milk containing 4% fat, suggesting that a lipid concentration as low as 4% does not alter the thermal resistance of B. subtilis spores. Providing that the pH range is kept between 3.4 to 10 and that sufficiently low concentrations of Ca2+ competitors or complexants are present in the medium, immobilized bioindicators may serve as an efficient, accurate, and reliable tool with which to validate the efficiency of any sterilization process. The environmental factors (pH, media composition) affecting the thermoresistance of native contaminants are intrinsically reflected in the F-value, allowing for a sharper adjustment of the sterilization process. Immobilized spores of B. stearothermophilus were successfully used to validate a resonance and interference microwave system that is believed to offer a convenient alternative for the sterilization of temperature-sensitive products and medical wastes.
Collapse
Affiliation(s)
- D Serp
- Department of Chemistry, Swiss Federal Institute of Technology (EPFL), Lausanne
| | | | | |
Collapse
|
15
|
Tejedor W, Rodrigo M, Martínez A. Modeling the combined effect of pH and temperature on the heat resistance of Bacillus stearothermophilus spores heated in a multicomponent food extract. J Food Prot 2001; 64:1631-5. [PMID: 11601720 DOI: 10.4315/0362-028x-64.10.1631] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The combined effect of pH and temperature on the heat resistance of Bacillus stearothermophilus spores heated in an extract of complex food was studied. The results showed that, in general, reducing the pH reduced the heat resistance of the spores. Similarly, the value for the D parameter in the nonacidified extract was between 30 and 70% lower than the one obtained with double-distilled water. This result once again shows the importance of the substrate in inactivation studies of microorganisms. The experimental data were used to carry out a comparison of two predictive mathematical models of inactivation, one based on a multiparametric regression obtained in this study and the other obtained from the bibliography and based on a linear-Bigelow equation. Both models predict reasonably well, although the multiparametric model presented a slightly better accuracy factor (1.11) than the one obtained with the linear-Bigelow equation (1.13).
Collapse
Affiliation(s)
- W Tejedor
- Instituto de Agroquímica y Tecnología de Alimentos, Valencia, Spain
| | | | | |
Collapse
|