Influence of Sodium Chloride on Thermal Inactivation and Recovery of Nonproteolytic Clostridium botulinum Type B Strain KAP B5 Spores†

1995 ◽  
Vol 58 (7) ◽  
pp. 813-816 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
BRIAN S. EBLEN

Demand for minimally processed refrigerated foods with reduced salt levels has stimulated renewed interest in the potential for survival and growth of psychrotrophic, nonproteolytic Clostridium botulinum type B spores. As part of a project to better define food-processing requirements, the heat resistance (75 to 90°C) of nonproteolytic C. botulinum type B spores was assessed in turkey containing 1 to 3% (wt/vol) salt (sodium chloride). Heated spores were recovered both on reinforced clostridial medium (RCM) with lysozyme and on RCM having the same salt levels as the heating menstruum. When the recovery medium contained no salt, D-values in turkey slurry containing 1% salt were 42.1, 17.1, 7.8, and 1.1 min at 75, 80, 85, and 90°C, respectively. Increasing levels (2 and 3%, wt/vol) of salt in the turkey slurry reduced the heat resistance as evidenced by reduced spore D-values. Also, apparent or measured heat resistance was decreased with increasing salt concentration in the heating menstruum and the recovery medium. The z-values in turkey slurry for all treatments were similar, ranging from 8.47 10 10.08°C.These data will assist food processors to design thermal processes that ensure safety against nonproteolytic C. botulinum type B spores in cook/chill foods while minimizing quality losses.

1978 ◽  
Vol 41 (5) ◽  
pp. 351-353 ◽  
Author(s):  
THERON E. ODLAUG ◽  
IRVING J. PFLUG ◽  
DONALD A. KAUTTER

The heat resistance of ten Clostridium botulinum type B spore crops was determined in mushroom puree and 0.067M Sorenson phosphate buffer (pH 7). The spore crops were grown from Clostridium botulinum isolates obtained from commercially canned mushrooms. The D-values for all of the C. botulinum spore crops were overall slightly higher in the buffer than in mushroom puree. The mean D(110.0 C)-value for the ten spore crops in buffer was 1.17 min and for the spores in mushroom puree the mean D(110.0 C)-value was 0.78 min. The mean D(115.6 C)-value in buffer for the ten spore crops was 0.24 min compared to a mean D(115.6 C)-value of 0.19 min for spores in mushroom puree. The C. botulinum type B spores tested in this study had a heat resistance that was less than the classical heat resistance for C. botulinum spores.


2014 ◽  
Vol 77 (10) ◽  
pp. 1696-1702 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
JIMENA GARCIA-DÁVILA ◽  
JULIO CESAR LOPEZ-ROMERO ◽  
ETNA AIDA PENA-RAMOS ◽  
JUAN PEDRO CAMOU ◽  
...  

The interactive effects of heating temperature (55 to 65°C), sodium chloride (NaCl; 0 to 2%), and green tea 60% polyphenol extract (GTPE; 0 to 3%) on the heat resistance of a five-strain mixture of Listeria monocytogenes in ground turkey were determined. Thermal death times were quantified in bags that were submerged in a circulating water bath set at 55, 57, 60, 63, and 65°C. The recovery medium was tryptic soy agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. D-values were analyzed by second-order response surface regression for temperature, NaCl, and GTPE. The data indicated that all three factors interacted to affect the inactivation of the pathogen. The D-values for turkey with no NaCl or GTPE at 55, 57, 60, 63, and 65°C were 36.3, 20.8, 13.2, 4.1, and 2.9 min, respectively. Although NaCl exhibited a concentration-dependent protective effect against heat lethality on L. monocytogenes in turkey, addition of GTPE rendered the pathogen more sensitive to the lethal effect of heat. GTPE levels up to 1.5% interacted with NaCl and reduced the protective effect of NaCl on heat resistance of the pathogen. Food processors can use the predictive model to design an appropriate heat treatment that would inactivate L. monocytogenes in cooked turkey products without adversely affecting the quality of the product.


2013 ◽  
Vol 76 (8) ◽  
pp. 1384-1392 ◽  
Author(s):  
N. RUKMA REDDY ◽  
KRISTIN M. MARSHALL ◽  
TRAVIS R. MORRISSEY ◽  
VIVIANA LOEZA ◽  
EDUARDO PATAZCA ◽  
...  

The aim of this study was to determine the resistance of multiple strains of Clostridium botulinum type A and proteolytic type B spores exposed to combined high pressure and thermal processing and compare their resistance with Clostridium sporogenes PA3679 and Bacillus amyloliquefaciens TMW-2.479-Fad-82 spores. The resistance of spores suspended in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) buffer (0.05 M, pH 7.0) was determined at a process temperature of 105°C, with high pressures of 600, 700, and 750 MPa by using a laboratory-scale pressure test system. No surviving spores of the proteolytic B strains were detected after processing at 105°C and 700 MPa for 6 min. A >7-log reduction of B. amyloliquefaciens spores was observed when processed for 4 min at 105°C and 700 MPa. D-values at 105°C and 700 MPa for type A strains ranged from 0.57 to 2.28 min. C. sporogenes PA3679 had a D-value of 1.48 min at 105°C and 700 MPa. Spores of the six type A strains with high D-values along with C. sporogenes PA3679 and B. amyloliquefaciens were further evaluated for their pressure resistance at pressures 600 and 750 MPa at 105°C. As the process pressure increased from 600 to 750 MPa at 105°C, D-values of some C. botulinum strains and C. sporogenes PA3679 spores decreased (i.e., 69-A, 1.91 to 1.33 min and PA3679, 2.35 to 1.29 min). Some C. botulinum type A strains were more resistant than C. sporogenes PA3679 and B. amyloliquefaciens to combined high pressure and heat, based on D-values determined at 105°C. Pulsed-field gel electrophoresis (PFGE) was also performed to establish whether strains with a similar restriction banding pattern also exhibited similar D-values. However, no correlation between the genomic background of a strain and its resistance to high pressure processing was observed, based on PFGE analysis. Spores of proteolytic type B strains of C. botulinum were less resistant to combined high pressure and heat (700 MPa and 105°C) treatment when compared with spores of type A strains.


1995 ◽  
Vol 58 (7) ◽  
pp. 758-763 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
BRIAN S. EBLEN ◽  
BENNE S. MARMER ◽  
AARON C. WILLIAMS ◽  
SAMUEL A. PALUMBO ◽  
...  

The heat resistance of nonproteolytic type B and type E Clostridium botulinum spores in phosphate buffer and turkey slurry was determined from 70 to 90°C. Thermal-death times were determined in vials heated using a water bath. Recovery of heat-injured spores was on reinforced clostridial medium (RCM) and tryptic soy agar (TSA) with and without added lysozyme (10 μg/ml). Decimal-reduction times (D-values) were determined by fitting a survival model to the data using a curve-fitting program. The apparent or measured heat resistance was maximum with RCM supplemented with lysozyme. The D-values at 80°C for type E spores in buffer ranged from 1.03 min for strain Whitefish to 4.51 min for strain Saratoga. The D-value for the most heat-resistant nonproteolytic type B strain KAP B5 in buffer was 4.31 min at 80°C. The z-values in buffer for all strains were very similar, ranging from 8.35 to 10.08°C.Turkey slurry offered protection to the spores with a concomitant increase in heat resistance. The D-values in turkey slurry ranged from 51.89 min at 70°C to 1.18min at 85°C for type E strain Alaska (z = 9.90°C) and from 32.53 min at 75°C to 0.80 min at 90°C for nonproteolytic type B strain KAP B5 (z = 9.43°C). Thermal-death-time values from this study will assist food processors to design thermal processes that ensure safety against nonproteolytic C. botulinum in cook/chill foods.


1984 ◽  
Vol 47 (6) ◽  
pp. 463-466 ◽  
Author(s):  
RICHARD K. LYNT ◽  
HAIM M. SOLOMON ◽  
DONALD A. KAUTTER

The heat resistance of two strains of Clostridium botulinum type G in phosphate buffer was studied by the thermal death time (TDT) tube method and the thermal destruction rate (TDR) method. The strains were estimated to have one highly heat-resistant spore among approximately 100 spores or 10,000 relatively heat-labile spores. The heat-labile spores were studied by the TDR method and the heat-resistant spores by the TDT tube method. Decimal reduction times (D) for the heat-labile spores were determined by the slopes of the survivor curves. D values for strain 89 ranged from 0.6 min at 190°F to 6.9 min at 170°F and for strain 2739 from 0.9 min at 200°F to 5.9 min at 180°F. Thermal destruction curves for the heat-labile spores gave z values of 24.0 and 17.5 for two spore stocks of strain 89 and 26.0 for strain 2739. D values for the heat-resistant spores, calculated from the combined data of replicate experiments by the Schmidt probability method, ranged from 0.29 min at 240°F to 1.51 min at 210°F for strain 89 and from 0.25 min at 240°F to 1.48 min at 210°F for strain 2739. Extrapolated to 250°F, the thermal destruction curves of the heat-resistant spores gave D250 values of 0.14 to 0.19 min. The thermal destruction curves of the heat-resistant spores were very flat, however, with z values of 37.9 and 49.1 for the two spore stocks of strain 89 and 37.7 for strain 2739. Low-acid canned food processes will provide the same margin of safety for type G as for other proteolytic strains of C. botulinum but ultra high processing temperatures probably will not.


1994 ◽  
Vol 269 (14) ◽  
pp. 10498-10503 ◽  
Author(s):  
T. Nishiki ◽  
Y. Kamata ◽  
Y. Nemoto ◽  
A. Omori ◽  
T. Ito ◽  
...  

1985 ◽  
Vol 48 (3) ◽  
pp. 265-276 ◽  
Author(s):  
J. SIMUNOVIC ◽  
J.L. OBLINGER ◽  
J.P. ADAMS

Type E and nonproteolytic type B strains of Clostridium botulinum can grow and produce toxin at temperatures below 5°C. Recent publications describing the greater heat resistance of nonproteolytic type B C. botulinum spores than type E spores are discussed in relation to suitable proess lethalities required for a safe pasteurized product. The incidences of botulism in Europe caused by nonproteolytic type B spores were compared to the lack of such incidences in the U.S. and to published procedures for isolating the causative agent for botulism. The incidence of C. botulinum spores in meat products in the U.S. also is reviewed.


2004 ◽  
Vol 70 (5) ◽  
pp. 2928-2934 ◽  
Author(s):  
Maria Lövenklev ◽  
Ingrid Artin ◽  
Oskar Hagberg ◽  
Elisabeth Borch ◽  
Elisabet Holst ◽  
...  

ABSTRACT The effects of carbon dioxide, sodium chloride, and sodium nitrite on type B botulinum neurotoxin (BoNT/B) gene (cntB) expression in nonproteolytic Clostridium botulinum were investigated in a tryptone-peptone-yeast extract (TPY) medium. Various concentrations of these selected food preservatives were studied by using a complete factorial design in order to quantitatively study interaction effects, as well as main effects, on the following responses: lag phase duration (LPD), growth rate, relative cntB expression, and extracellular BoNT/B production. Multiple linear regression was used to set up six statistical models to quantify and predict these responses. All combinations of NaCl and NaNO2 in the growth medium resulted in a prolonged lag phase duration and in a reduction in the specific growth rate. In contrast, the relative BoNT/B gene expression was unchanged, as determined by the cntB-specific quantitative reverse transcription-PCR method. This was confirmed when we measured the extracellular BoNT/B concentration by an enzyme-linked immunosorbent assay. CO2 was found to have a major effect on gene expression when the cntB mRNA levels were monitored in the mid-exponential, late exponential, and late stationary growth phases. The expression of cntB relative to the expression of the 16S rRNA gene was stimulated by an elevated CO2 concentration; the cntB mRNA level was fivefold greater in a 70% CO2 atmosphere than in a 10% CO2 atmosphere. These findings were also confirmed when we analyzed the extracellular BoNT/B concentration; we found that the concentrations were 27 ng · ml−1 · unit of optical density−1 in the 10% CO2 atmosphere and 126 ng · ml−1 · unit of optical density−1 in the 70% CO2 atmosphere.


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