Characterizing asymptotic D-values for Salmonella spp. subjected to different heating rates in sous-vide cooked beef

2003 ◽  
Vol 4 (4) ◽  
pp. 395-402 ◽  
Author(s):  
V.K. Juneja ◽  
H.M. Marks
Keyword(s):  
Heating Rates ◽  
Salmonella Spp ◽  
Sous Vide ◽  
D Values

Survival of Campylobacter jejuni in Fresh and Heated Red Meat

1983 ◽  
Vol 46 (9) ◽  
pp. 771-774 ◽  
Author(s):  
PAUL KOIDIS ◽  
MICHAEL P. DOYLE
Keyword(s):  
Heat Treatment ◽  
Campylobacter Jejuni ◽  
Ground Beef ◽  
Red Meat ◽  
Refrigerated Storage ◽  
Log10 Reduction ◽  
Salmonella Spp ◽  
Lamb Meat ◽  
Large Numbers ◽  
D Values

Studies were done to assess the ability of Campylobacter jejuni to survive in fresh ground beef during refrigerated storage and to identify time-temperature treatments needed to inactivate Campylobacter in ground and cubed red meat. The organism survived well in refrigerated ground beef containing large numbers of indigenous bacteria. Relatively little death (< 1.2-log10 reduction) occurred for 7 of 8 strains during 14 d at 4°C. C. jejuni inoculated into ground beef and cubed lamb meat was quite sensitive to heat treatment. D-values for inactivation of campylobacters in ground beef ranged from 5.9 to 6.3 min at 50°C and from 12 to 21 s at 58°C. D-values were generally greater when campylobacters were heated in lamb meat, ranging from 5.9 to 13.3 min and 12.5 to 15.8 s at 50 and 60°C, respectively. All strains of C. jejuni were more sensitive to heat than salmonellae, hence meat heated to a temperature sufficient to inactivate Salmonella spp. should be free of viable campylobacters.

scholarly journals Impact of overcrowding sous vide water baths on the thermal process of pork loins

2018 ◽  
Author(s):  
Jessica Wu ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Helen Heacock ◽  
Lorraine McIntyre ◽  
Sion Shyng
Keyword(s):  
Thermal Process ◽  
Water Circulation ◽  
Water Bath ◽  
Cold Spot ◽  
Log10 Reduction ◽  
Salmonella Spp ◽  
Log Reduction ◽  
Organoleptic Characteristics ◽  
Pork Loin ◽  
Sous Vide

  Background: In the culinary industry, sous vide is a popular cooking method in which lower temperatures are used to cook food to retain more desirable organoleptic characteristics. However, this technique may compromise food safety as the temperature may not be sufficient enough to eliminate pathogens that may be present. The BCCDC’s Guidelines for Restaurant Sous Vide Cooking Safety in British Columbia advises when too many food items are placed in the sous vide water bath, inadequate water circulation may occur with the result that process lethality, measured by calculation of log10 reductions, may not be achieved. The purpose of this study was to determine how overcrowding a sous vide water bath would impact the thermal process of pork loins. Methods: Each pork loin sample had a SmartButton inserted and was vacuum sealed in a plastic bag. The water bath was preheated to 60˚C by an immersion circulator. Under normal conditions, six pork loin samples were held in the water bath for 1 hour and the process was repeated four more times. Under overcrowded conditions, two runs were conducted for 1.5 to 2 hours, each consisting of 15 samples stacked in three layers. SmartButton temperature values were used to calculate whether a 6.5 log10 reduction for Salmonella spp. was achieved, using the American Meat Institute’s formula. Results: Using a 31-minute cook time, pork loins in normal conditions reached an average log reduction of 8.85 (range: 0.51 to 21.07), which was significantly higher than the 6.5 log10 reduction objective (p = 0.006). Conversely, pork loins in overcrowded conditions reached an average log reduction of 1.76 (range: 0.05 to 7.93), which was significantly lower than the 6.5 log10 reduction objective (p = 0.000). Furthermore, cooking lethality between the two conditions, pork loins in crowded and overcrowded conditions, were found to be significantly different from each other (p = 0.000). No differences were found in the mean log10 reductions between the pork loins placed in each of the three layers in an overcrowded water bath at 31 minutes (p = 0.094). Conclusion: Overcrowding sous vide water baths does impact on the thermal process of pork loins. Food products cooked under overcrowded conditions require a longer cook time, (approximately 30 minutes longer) to achieve at least 6.5 log10 reductions. Therefore, it is advised that food handlers using sous vide techniques should avoid overcrowding sous vide water baths. Further research using more samples is recommended to determine potential cold spot patterns in overcrowded water baths due to inadequate water circulation.  

Thermal Inactivation Kinetics of Salmonella spp. within Intact Eggs Heated Using Humidity-Controlled Air

2001 ◽  
Vol 64 (7) ◽  
pp. 934-938 ◽  
Author(s):  
R. E. BRACKETT ◽  
J. D. SCHUMAN ◽  
H. R. BALL ◽  
A. J. SCOUTEN
Keyword(s):  
Thermal Inactivation ◽  
Inactivation Kinetics ◽  
Glass Capillary ◽  
Salmonella Spp ◽  
Shell Eggs ◽  
Log Reduction ◽  
Liquid Whole Egg ◽  
D Values ◽  
Kinetics Of ◽  
Whole Egg

The heat resistance of six strains of Salmonella (including Enteritidis, Heidelberg, and Typhimurium) in liquid whole egg and shell eggs was determined. Decimal reduction times (D-values) of each of the six strains were determined in liquid whole egg heated at 56.7°C within glass capillary tubes immersed in a water bath. D-values ranged from 3.05 to 4.09 min, and significant differences were observed between the strains tested (α = 0.05). In addition, approximately 7 log10 CFU/g of a six-strain cocktail was inoculated into the geometric center of raw shell eggs and the eggs heated at 57.2°C using convection currents of humidity-controlled air. D-values of the pooled salmonellae ranged from 5.49 to 6.12 min within the center of intact shell eggs. A heating period of 70 min or more resulted in no surviving salmonellae being detected (i.e., an 8.7-log reduction per egg).

Thermal Resistance of Listeria monocytogenes and Salmonella spp. in Liquid Egg White

1996 ◽  
Vol 59 (11) ◽  
pp. 1182-1186 ◽  
Author(s):  
M. S. PALUMBO ◽  
S. M. BEERS ◽  
S. BHADURI ◽  
S. A. PALUMBO
Keyword(s):  
Hydrogen Peroxide ◽  
Listeria Monocytogenes ◽  
Salmonella Enteritidis ◽  
Egg White ◽  
Heat Sensitivity ◽  
Salmonella Spp ◽  
Single Strain ◽  
Ph Values ◽  
D Values ◽  
Unit Reduction

Survival of a five-strain mixture of Listeria monocytogenes and a six-strain mixture of Salmonella enteritidis, S. typhimurium, and S. senftenberg (not 775W) in liquid egg white was determined by a submerged-vial technique at 51.5°C and 53.2°C with 0.875% added H2O2 and at 55.5°C, 56.6°C, and 57.7°C with no additions. Survival at a range of pH values at 56.6°C also was determined. Surviving bacteria were counted on tryptic soy agar and results expressed as D-values; log-unit reductions in counts in 3.5 min or 6.2 min were calculated from these D-values. Plate pasteurization of commercially broken egg white (pH 8.8) inoculated with a single strain of L. innocua or S. senftenberg also was performed. Heating under currently approved pasteurization conditions, 51.5°C for 3.5 min with hydrogen peroxide, 55.6°C for 6.2 min, or 56.7°C for 3.5 min, resulted in a less than 3-1og unit reduction of viable Salmonella spp. and a less than 0.5-1og unit reduction of L. monocytogenes. At 53.2°C with peroxide, plate pasteurization resulted in a 3.44-1og unit reduction of S. senftenberg in 3.5 min. At 57.7°C with no peroxide, the D-value for Salmonella spp. was 0.78 min when heated in submerged vials, and plate pasteurization reduced viable numbers by 3.64 log units in 3.5 min. Destruction of Listeria under these conditions was still less than 1 log unit. Variation in the pH of the egg white from 7.8 to 9.3 resulted in D-values for Salmonella spp. at 56.6°C of 3.60 min to 1.08 min, respectively. D-values for L. monocytogenes under these conditions ranged from 10.4 min at pH 7.8 to 20.9 min at pH 9.3. The reduced heat sensitivity of Salmonella spp. at lower pH values should be considered in reevaluating pasteurization procedures.

Elimination by Gamma Irradiation of Salmonella spp. and Strains of Staphylococcus aureus Inoculated in Bison, Ostrich, Alligator, and Caiman Meat†

1997 ◽  
Vol 60 (7) ◽  
pp. 756-760 ◽  
Author(s):  
DONALD W. THAYER ◽  
GLENN BOYD ◽  
JAY B. FOX ◽  
LEON LAKRITZ
Keyword(s):  
Staphylococcus Aureus ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Radiation Resistance ◽  
Radiation Doses ◽  
Salmonella Spp ◽  
Salmonella Dublin ◽  
Food Borne Pathogens ◽  
Food Borne ◽  
D Values

There is an expanding industry for the marketing of high-value meats from animals other than the typical domesticated species, including, but not limited to, bison, ostrich, alligator, and caiman. In this study we compared the gamma radiation resistance of a mixture of salmonellae (Salmonella dublin, S. enteritidis, S. newport, S. senftenberg, and S. typhimurium) and a mixture of Staphylococcus aureus strains (ATCC 13565, ATCC 25923, and B124) when present on ground bison, ostrich, alligator, and caiman meats at 5°C. A minimum of five doses were used to establish the D values, and the studies were replicated three times. Because the type of meat did not significantly (P < 0.05) alter the radiation resistance of salmonellae and of S. aureus only slightly in the case of ostrich meat, all of the results for each organism were combined to obtain radiation D values of 0.53 ± 0.02 and 0.37 ± 0.01 kGy for Salmonella spp. and S. aureus, respectively. The authors conclude that both of these food-borne pathogens, if present, can be eliminated or greatly reduced in number, depending upon the level of contamination, from these meats by gamma radiation doses between 1.5 and 3.0 kGy at 5°C, the doses currently approved by the FDA and USDA for the irradiation of poultry. The authors also conclude that similar, if not identical, control of food-borne pathogens should be expected on edible meats in general, not just on those that are generically related.

Thermal Resistance of Salmonella spp. and Listeria monocytogenes in Liquid Egg Yolk and Egg Yolk Products†

1995 ◽  
Vol 58 (9) ◽  
pp. 960-966 ◽  
Author(s):  
MARY S. PALUMBO ◽  
SHARON M. BEERS ◽  
SAUMYA BHADURI ◽  
SAMUEL A. PALUMBO
Keyword(s):  
Listeria Monocytogenes ◽  
Thermal Resistance ◽  
Minimum Temperature ◽  
Salmonella Enteritidis ◽  
Egg Yolk ◽  
Salmonella Spp ◽  
Egg Products ◽  
D Values ◽  
Unit Reduction ◽  
D Value

The effectiveness of various pasteurization procedures in destroying Listeria monocytogenes and Salmonella enteritidis in liquid egg products was evaluated. Survivor studies were perfonned on individual strains of L. monocytogenes and L. innocua in commercially broken raw egg yolk samples after heating at 61.1, 63.3, and 64.4°C using submerged vials, and on Salmonella spp. at 60.0, 61.1, and 62.2°C. Surviving bacteria were enumerated on TSA and results expressed as D-values. The influence of aw -lowering ingredients such as salt and sugar on thermal resistance in yolk was investigated using a five-strain mixture of L. monocytogenes or a mixture of Salmonella spp. (four strains of S. enteritidis, one stain each of S. senftenberg and S. typhimurium) at 61.1°C to 66.7°C. At 61.1°C (present minimum temperature for pasteurization of plain egg yolk), a 7-log-unit reduction of Salmonella took 1.4 to 2.4 min, whereas a 7-log-unit reduction of L. monocytogenes took 4.9 to 16.1 min. The D-value for L. monocytogenes at 64.4°C increased from 0.44 min in plain yolk to 8.26 min after a 21.5-min lag (total time to achieve 1-log-unit reduction was 30.7 min) in yolk with 10% salt and 5% sugar, and 27.3 min after a 10.5-min lag (total time 37.8 min for 1-log-unit reduction) in yolk with 20% salt. The D-value for Salmonella in egg yolk at 64.4°C was < 0.2 min, but when 10% salt was added, the D-value was 6.4 min. Aw -lowering solutes in liquid egg yolk increased the thermal resistance of Salmonella and L. monocytogenes.

Effect of Grapefruit Seed Extract on Thermal Inactivation of Listeria monocytogenes during Sous-Vide Processing of Two Marinated Mexican Meat Entrées

2016 ◽  
Vol 79 (7) ◽  
pp. 1174-1180 ◽  
Author(s):  
MARTIN VALENZUELA-MELENDRES ◽  
E. AIDA PEÑA-RAMOS ◽  
VIJAY K. JUNEJA ◽  
JUAN PEDRO CAMOU ◽  
GERMAN CUMPLIDO-BARBEITIA
Keyword(s):  
Listeria Monocytogenes ◽  
Thermal Inactivation ◽  
Lethal Effect ◽  
Seed Extract ◽  
Log Reduction ◽  
Critical Control Points ◽  
Grapefruit Seed Extract ◽  
Sous Vide ◽  
D Values ◽  
Meat Samples

ABSTRACT D- and z-values for Listeria monocytogenes were obtained for two Mexican meat entrées: pork meat marinated in tomatillo (green tomato) sauce (PTS) and beef marinated in a red chili sauce (BRCS), with addition of 0, 200, and 800 ppm of grapefruit seed extract (GSE). Meat samples inoculated with L. monocytogenes were packaged in sterile bags, immersed in a water bath, and held at 55, 57.5, 60, and 62.5°C for different periods of time. Depending upon the temperature, D-values at 0 ppm of GSE ranged from 26.19 to 2.03 min in BRCS and 26.41 to 0.8 min in PTS. Adding 800 ppm of GSE to BRCS thermally treated at 55 and 62.5°C significantly decreased inactivation time by 35%. A reduction in time of 25.9, 10.6, and 40.1% at 55, 57.5, and 60°C, respectively, was observed in PTS with 800 ppm of GSE. The z-values of L. monocytogenes were not significantly affected by GSE addition; average z-values were 7.25 and 5.09°C for BRCS and PTS, respectively. Estimated thermal lethality for a 7-D log reduction of L. monocytogenes under commercial-size sous-vide conditions at a reference temperature of 55°C was reached at 78 and 71 min for BRCS without and with 800 ppm of GSE, respectively. For PTS, 7-D reduction was attained at 69 and 61 min without and with addition of 800 ppm of GSE, respectively. Supplementing both Mexican meat entrées (BRCS and PTS) with 800 ppm of GSE rendered L. monocytogenes cells more sensitive to the lethal effect of heat. The results of this study will assist the retail food industry in designing acceptance limits on critical control points pertaining to cooking regimes to effectively eliminate L. monocytogenes in BRCS and PTS sous-vide processed Mexican meat entrées.

Thermal Death Time Measurement Using Thin Flexible Sleeves: A New Experimental Approach for Determining Microbial Destruction Kinetics in Fluids of Arbitrary Viscosity

2010 ◽  
Vol 73 (12) ◽  
pp. 2301-2305 ◽  
Author(s):  
GREGORY J. FLEISCHMAN ◽  
MANI K. BADVELA ◽  
ANDRE REHKOPF ◽  
CYNTHIA M. STEWART
Keyword(s):  
Thin Layer ◽  
Salmonella Enteritidis ◽  
Heat Exposure ◽  
Egg Yolk ◽  
Heating Rates ◽  
Death Time ◽  
Thermal Death ◽  
Destruction Kinetics ◽  
D Values ◽  
Thermal Death Time

The thermal death time kinetics of Salmonella Enteritidis (SE) was measured in buffer, egg yolk, and albumen using thin layer plastic sleeves. The sleeves allowed for the loading and sampling of liquids of high or unusual viscosity, as in the case of yolk and albumen, and accepted relatively large volumes (2 to 3 ml) of fluid. The sleeves maintained the volume of the fluid in a thin layer and could be easily handled for heat exposure. The thin layer maintained one-dimensional heat transfer and minimized temperature gradients, thus preventing parts of the fluid from experiencing different heating rates. A representative strain of SE associated with an egg-based salmonellosis outbreak was used in this study. The D- and z-values of the chosen strain, H7037, were measured in buffer, yolk, and albumen. In buffer, SE had the following mean (±standard deviation) D-values: D55°C = 3.51 ± 0.30 min, D57°C = 1.75 ± 0.13 min, and D60°C = 0.25 ± 0.06 min. In yolk, D58°C = 0.90 ± 0.05, D60°C = 0.26 ± 0.03, and D62°C = 0.20 ± 0.02. In albumen, D55°C = 1.26 ± 0.31, D56°C = 0.68 ± 0.10, and D57°C = 0.44 ± 0.04. The z-values for SE calculated from these D-values were 4.29 ± 0.39°C in buffer, 6.12 ± 0.26°C in yolk, and 4.63 ± 1.14°C in albumen. The sleeves allowed one consistent approach to determining thermal death time kinetics regardless of viscosity.

scholarly journals Salmon (Salmo salar) Cooking: Achieving Optimal Quality on Select Nutritional and Microbiological Safety Characteristics for Ready-to-Eat and Stored Products

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5661
Author(s):  
Artur Głuchowski ◽  
Ewa Czarniecka-Skubina ◽  
Jarosława Rutkowska
Keyword(s):  
Fatty Acids ◽  
Matter Content ◽  
Dry Matter Content ◽  
Technological Parameters ◽  
Salmonella Spp ◽  
Microbiological Safety ◽  
Fatty Acids Profile ◽  
Energy Consuming ◽  
Sous Vide ◽  
Time And Energy

This study was performed in order to assess technological characteristics, proximate composition, fatty acids profile, and microbiological safety of sous-vide processed salmon in comparison with steaming and roasting. The cooking loss was lower in the sous-vide method (6.3–9.1%) than in conventional methods (11.6–16.2%). The preparation of salmon using sous-vide was more time- and energy-consuming than steaming. The dry matter content of the salmon fillets was higher in conventionally processed samples than sous-vide due to the evaporation of water, and it was connected with total protein (r = 0.85) and lipid content (r = 0.73). Analysis of the fatty acids profile only revealed significant differences in six fatty acids. All of the heat treatment methods ensured microbiological safety with regard to coagulase-positive Staphylococcus, E. coli, Listeria monocytogenes, and Salmonella spp. However, in sous-vide (57 °C, 20 min) and steamed samples after storage Enterobacteriaceae bacteria (<104) was detected. Summing up, high parameters of sous-vide salmon cooking, when considering both technological parameters, nutritional value, and microbiological status should be recommended.

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