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.  

scholarly journals The effects of cold pork loins on the pasteurization temperature in sous vide cooking

2018 ◽  
Author(s):  
David Xu Wang ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Helen Heacock ◽  
Lorraine McIntyre
Keyword(s):  
Bacterial Count ◽  
T Test ◽  
Water Bath ◽  
Internal Temperature ◽  
Cooking Temperature ◽  
Group 6 ◽  
Group A ◽  
Pork Loin ◽  
Sous Vide ◽  
Group B

  Objective: Sous vide is a relatively new cooking method introduced in restaurants in British Columbia. Sous vide cooking involves placing vacuum sealed food inside a temperature controlled water bath or steam convection oven. Unlike conventional cooking, sous vide cooking involves cooking food at a lower temperature (usually < 65°C) with a longer cook time. The low temperature allows chefs to precisely control the changes within the food. Thus sous vide cooked dishes have consistent texture and color, with retained flavor, moistness and nutrients. With all the benefits, sous vide cooking does have some disadvantages. Lower cooking temperature may not be sufficient for bacterial count reduction, resulting in unsafe food. In addition, every validated sous vide menu requires chefs to precisely follow the cooking temperature and cook time. Any deviation can cause the food to not reach the required 6.5 log reduction in bacterial count. The purpose of this experiment was to determine the effect on the internal temperature of cooking-in-process pork loin packages when additional chilled pork loin packages with an internal temperature of 4°C are submerged into the water bath. Methods: Two groups of pork loin packages with data loggers inside (SmartButton) at approximately 4°C were introduced into a 60°C water bath at different intervals. The first group (6 packages) was immersed inside the water bath at time = 0 minute, while the second group (6 packages) was immersed inside the water bath at time = 10 minutes. Both groups were taken out when they were cooked for 31 minutes (at time = 31 minutes and 41 minutes respectively). Water bath temperature was recorded using SPER Scientific 8000024 data logger. Temperature data for pork loin packages was used to calculate the mean lethality achieved by each group. One sample t-test and two sample t-test were used for statistical analysis. Results: There was a more than 3 mean log lethality difference in group A and group B pork loins. Pork loins cooked sous vide style in group A achieved a mean lethality of 5.12 at 31 minutes (range 0.42 to 12.78) while group B pork loins achieved a mean lethality of 8.44 at 31 minutes (range 3.35 to 11.87). With the same cook time, group A had a statistically significantly lower mean lethality than group B pork loins with p value = 0.003. Although statistically inconclusive whether group A pork loins achieved a mean lethality of 6.5, group B pork loins did reach the recommended mean lethality of 6.5. Conclusion: The result indicated when new cold pork loin packages at 4°C are introduced into a cooking-in-process sous vide water bath at 60°C, the lethality of the original pork loin packages in the bath will be lowered if the cook time remains unchanged. However, it is inconclusive on whether the original pork loin packages will reach 6.5 lethality recommended by BCCDC. The new pork loin packages will reach 6.5 lethality if the original cook time is used.  

scholarly journals 1146. Effectiveness of Ultraviolet Irradiation on Candida auris: A Laboratory Study

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S345-S345
Author(s):  
Gennifer Garmon ◽  
Dhammika Navarathna ◽  
John Coppin ◽  
Marjory Williams ◽  
Chetan Jinadatha
Keyword(s):  
Stainless Steel ◽  
Prolonged Exposure ◽  
Uv Light ◽  
Multidrug Resistant ◽  
Published Data ◽  
Log10 Reduction ◽  
Healthcare Associated Infection ◽  
Candida Auris ◽  
Light Emitting Devices ◽  
Log Reduction

Abstract Background Candida auris is a multidrug-resistant yeast which persists on healthcare surfaces for prolonged periods of time and is an emerging pathogen in hospitals. It has been linked to healthcare-associated infection (HAI) through surface transmission. Mobile ultraviolet (UV) light emitting devices from mercury sources have been shown to be effective in reducing C. auris bioburden but require prolonged exposure. In this study, we demonstrate the efficacy of an UV emitting device used in our hospital for terminal disinfection on C. auris. Methods Two C. auris strains (AR-381-CAU-01 and CAU-02) isolates obtained from Centers for Disease Prevention and Control (CDC) were used along with a Candida albicans (C. albicans) strain. An organism load of 10 μL containing 106 colony forming unit (CFU) was spread on a 20-mm diameter stainless steel coupon and exposed to the UV source from a pulsed xenon device at 5 feet distance and 4 feet height for 5, 10, and 30 minutes. Killing efficacy in terms of log reduction was calculated in comparison to untreated control coupons. Results Mean CFU log10 reduction for C. albicans, CAU-01, and CAU-02 was 0.547, 1.051, and 0.952 at 5 minutes; 1.412, 1.975, and 1.879 at 10 minutes; and 2.639, 3.971, and 4.145 at 30 minutes, respectively. Figure 1 describes the mean log10 reduction as well as the minimum and maximum log reduction by isolates. Conclusion Our study demonstrates the UV from a pulsed xenon device is effective in reducing the C. auris on stainless steel coupons. Similar to previously published data on reduction of C. auris by other UV sources, extended exposure is required to achieve a higher log reduction of C. auris. We did not have any C. auris clinical infections to assess efficacy of UV on HAI reduction. Disclosures C. Jinadatha, Xenex Healthcare Service: Grant Investigator, Research grant.

scholarly journals Processing of Biltong (Dried Beef) to Achieve USDA-FSIS 5-log Reduction of Salmonella without a Heat Lethality Step

2020 ◽  
Vol 8 (5) ◽  
pp. 791
Author(s):  
Caitlin E. Karolenko ◽  
Arjun Bhusal ◽  
Jacob L. Nelson ◽  
Peter M. Muriana
Keyword(s):  
Repeated Measures ◽  
Salmonella Enteritidis ◽  
The United States ◽  
Moisture Loss ◽  
United States Department ◽  
Log10 Reduction ◽  
Log Reduction ◽  
Salmonella Hadar ◽  
The Usa ◽  
Inspection Service

In the US, dried beef products (beef jerky) are a popular snack product in which the manufacture often requires the use of a heat lethality step to provide adequate reduction of pathogens of concern (i.e., 5-log reduction of Salmonella as recommended by the United States Department of Agriculture Food Safety and Inspection Service (USDA-FSIS)). Biltong, a South African-style dried beef product, is manufactured with low heat and humidity. Our objectives were to examine processes for the manufacture of biltong that achieves a 5-log reduction of Salmonella without a heat lethality step and with, or without, the use of additional antimicrobials. Beef pieces (1.9 cm × 5.1 cm × 7.6 cm) were inoculated with a 5-serovar mixture of Salmonella (Salmonella Thompson 120, Salmonella Heidelberg F5038BG1, Salmonella Hadar MF60404, Salmonella Enteritidis H3527, and Salmonella Typhimurium H3380), dipped in antimicrobial solutions (lactic acid, acidified calcium sulfate, sodium acid sulfate) or water (no additional antimicrobial), and marinaded while vacuum tumbling and/or while held overnight at 5 °C. After marination, beef pieces were hung in an oven set at 22.2 °C (72 °F), 23.9 °C (75 °F), or 25 °C (77 °F) depending on the process, and maintained at 55% relative humidity. Beef samples were enumerated for Salmonella after inoculation, after dip treatment, after marination, and after 2, 4, 6, and 8 days of drying. Water activity was generally <0.85 by the end of 6–8 days of drying and weight loss was as high as 60%. Trials also examined salt concentration (1.7%, 2.2%, 2.7%) and marinade vinegar composition (2%, 3%, 4%) in the raw formulation. Nearly all approaches achieved 5-log10 reduction of Salmonella and was attributed to the manner of microbial enumeration eliminating the effects of microbial concentration on dried beef due to moisture loss. All trials were run as multiple replications and statistical analysis of treatments were determined by repeated measures analysis of variance (RM-ANOVA) to determine significant differences (p < 0.05). We believe this is the first published report of a biltong process achieving >5.0 log10 reduction of Salmonella which is a process validation requirement of USDA-FSIS for the sale of dried beef in the USA.

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 (&lt; 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 Effect of sous-vide heat treatment on the phthalic acid esters content in meat

10.5219/1081 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 622-627
Author(s):  
Alžbeta Jarošová ◽  
Marcela Jandlová ◽  
Josef Kameník
Keyword(s):  
Heat Treatment ◽  
Phthalic Acid ◽  
Treatment Temperature ◽  
Water Bath ◽  
Phthalic Acid Esters ◽  
Heat Treated ◽  
Sous Vide ◽  
Meat Samples ◽  
Ethylhexyl Phthalate ◽  
Acid Esters

The aim of the study was to monitor the migration of the phthalic acid esters dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) from packaging to meat wrapped in plastic when heat treated by sous-vide method. A heat treatment temperature of 80 °C was used for 4 and 8 hours with reheating at 80 °C for 1 hour. The average DBP and DEHP concentrations in meat ranged from 2.24 to 4.66 mg.kg-1 and 2.29 to 10.35 mg.kg-1 of the original sample, respectively. The average DBP and DEHP concentrations found in plastic packaging ranged from 3.06 to 6.37 µg.g-1 and 5.70 to 7.83 µg.g-1 of plastic, respectively. The average concentrations of DBP in water bath range from 16.25 to 23.38 µg.l-1, while the average concentrations of DEHP in water bath were determined between 0.24 and 1.82 µg.l-1. The above results were compared with the results measured at sous-vide treatment temperature of 70 °C for 4 hours, 8 hours, and with 1 hour of reheating. The average concentrations of DBP and DEHP in all meat samples exceeded the specific migration limits of both phthalates (0.3 mg.kg-1 for DBP and 1.5 mg.kg-1 for DEHP).

Validation of Apple Cider Pasteurization Treatments against Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes

2001 ◽  
Vol 64 (11) ◽  
pp. 1679-1689 ◽  
Author(s):  
PEGGY P. MAK ◽  
BARBARA H. INGHAM ◽  
STEVEN C. INGHAM
Keyword(s):  
Escherichia Coli ◽  
New York ◽  
Listeria Monocytogenes ◽  
Fluorescent Protein ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction ◽  
Green Fluorescent

Time and temperature pasteurization conditions common in the Wisconsin cider industry were validated using a six-strain cocktail of Escherichia coli O157:H7 and acid-adapted E. coli O157:H7 in pH- and ∘Brix-adjusted apple cider. Strains employed were linked to outbreaks (ATCC 43894 and 43895, C7927, and USDA-FSIS-380–94) or strains engineered to contain the gene for green fluorescent protein (pGFP ATCC 43894 and pGFP ATCC 43889) for differential enumeration. Survival of Salmonella spp. (CDC 0778, CDC F2833, and CDC HO662) and Listeria monocytogenes (H0222, F8027, and F8369) was also evaluated. Inoculated cider of pH 3.3 or 4.1 and 11 or 14°Brix was heated under conditions ranging from 60°C for 14 s to 71.1°C for 14 s. A 5-log reduction of nonadapted and acid-adapted E. coli O157:H7 was obtained at 68.1°C for 14 s. Lower temperatures, or less time at 68.1°C, did not ensure a 5-log reduction in E. coli O157:H7. A 5-log reduction was obtained at 65.6°C for 14 s for Salmonella spp. L. monocytogenes survived 68.1°C for 14 s, but survivors died in cider within 24 h at 4°C. Laboratory results were validated with a surrogate E. coli using a bench-top plate heat-exchange pasteurizer. Results were further validated using fresh unpasteurized commercial ciders. Consumer acceptance of cider pasteurized at 68.1°C for 14 s (Wisconsin recommendations) and at 71.1°C for 6 s (New York recommendations) was not significantly different. Hence, we conclude that 68.1°C for 14 s is a validated treatment for ensuring adequate destruction of E. coli O157:H7, Salmonella spp., and L. monocytogenes in apple cider.

scholarly journals A Small Study of Bacterial Contamination of Anaerobic Digestion Materials and Survival in Different Feed Stocks

2020 ◽  
Vol 7 (3) ◽  
pp. 116
Author(s):  
Lauren Russell ◽  
Paul Whyte ◽  
Annetta Zintl ◽  
Stephen Gordon ◽  
Bryan Markey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Anaerobic Digestion ◽  
Enterococcus Faecalis ◽  
Food Waste ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Clostridium Sporogenes ◽  
Log Reduction ◽  
Clostridium Spp

If pathogens are present in feedstock materials and survive in anaerobic digestion (AD) formulations at 37 °C, they may also survive the AD process to be disseminated in digestate spread on farmland as a fertilizer. The aim of this study was to investigate the prevalence of Salmonella spp., Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium spp. in AD feed and output materials and survival/growth in four formulations based on food waste, bovine slurry and/or grease-trap waste using International Organization for Standardization (ISO) or equivalent methods. The latter was undertaken in 100 mL Ramboldi tubes, incubated at 37 °C for 10 d with surviving cells enumerated periodically and the T90 values (time to achieve a 1 log reduction) calculated. The prevalence rates for Salmonella spp., Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium spp. were 3, 0, 5, 11 and 10/13 in food waste, 0, 0, 2, 3 and 2/3 in bovine slurry, 1, 0, 8, 7 and 8/8 in the mixing tank, 5, 1, 17, 18 and 17 /19 in raw digestate and 0, 0, 0, 2 and 2/2 in dried digestate, respectively. Depending on the formulation, T90 values ranged from 1.5 to 2.8 d, 1.6 to 2.8 d, 3.1 to 23.5 d, 2.2 to 6.6 d and 2.4 to 9.1 d for Salmonella Newport, Escherichia coli O157, Listeria monocytogenes, Enterococcus faecalis and Clostridium sporogenes, respectively. It was concluded that AD feed materials may be contaminated with a range of bacterial pathogens and L. monocytogenes may survive for extended periods in the test formulations incubated at 37 °C.

scholarly journals Mucosal Competitive Exclusion to Reduce Salmonella in Swine

1999 ◽  
Vol 62 (12) ◽  
pp. 1376-1380 ◽  
Author(s):  
PAULA J. FEDORKA-CRAY ◽  
J. STAN BAILEY ◽  
NORMAN J. STERN ◽  
NELSON A. COX ◽  
SCOTT R. LADELY ◽  
...  
Keyword(s):  
Competitive Exclusion ◽  
Clinical Signs ◽  
Log10 Reduction ◽  
Oral Gavage ◽  
Salmonella Spp ◽  
Salmonella Choleraesuis ◽  
Rectal Swabs ◽  
Intranasal Instillation

A mucosal competitive exclusion culture has been shown to reduce or eliminate Salmonella spp. in poultry. Using similar techniques, a mucosal competitive exclusion culture from swine (MCES) was produced from the cecum of a 6-week-old pig. Suckling pigs were inoculated with 5 ml of MCES by oral gavage within 6 h postfarrowing (PF) and again at 24 h PF. All pigs were challenged with 103 CFU of Salmonella Choleraesuis at 48 h PF by intranasal instillation, including pigs from two sows that had not been given MCES. Clinical signs and rectal swabs were monitored daily, and pigs were allowed to suckle throughout the experiment. All pigs underwent necropsy on day 7 PF, and presence of Salmonella was determined in both qualitative (10 tissues) and quantitative (two tissues) samples. Clinical signs were inapparent in all pigs throughout the experiment. Recovery of Salmonella from rectal swabs was variable. However, 28% of the gut tissues were positive from the MCES-treated pigs versus 79% from the control pigs. A 2- to 5-log10 reduction of Salmonella in the cecal contents or ileocolic junction was observed in the MCES-treated pigs when compared with the controls. These data indicate that use of MCES may be a useful approach for control of Salmonella.

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