Survival of Escherichia coli O157:H7 during Storage in Pressure-Treated Orange Juice

1999 ◽  
Vol 62 (9) ◽  
pp. 1038-1040 ◽  
Author(s):  
M. LINTON ◽  
J. M. J. McCLEMENTS ◽  
M. F. PATTERSON
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Orange Juice ◽  
Ambient Pressure ◽  
Storage Period ◽  
High Pressure Processing ◽  
Escherichia Coli O157 ◽  
Pressure Treatment ◽  
E Coli ◽  
Time Required

The effect of a high-pressure treatment on the survival of a pressure-resistant strain of Escherichia coli O157:H7 (NCTC 12079) in orange juice during storage at 3°C was investigated over the pH range of 3.4 to 5.0. The pH of shelf-stable orange juice was adjusted to 3.4, 3.6, 3.9, 4.5, and 5.0 and inoculated with 108 CFU ml−1 of E. coli O157:H7. The orange juice was then pressure treated at 400 MPa for 1 min at 10°C or was held at ambient pressure (as a control). Surviving E. coli O157: H7 cells were enumerated at 1-day intervals during a storage period of 25 days at 3°C. Survival of E. coli O157:H7 during storage was dependent on the pH of the orange juice. The application of high pressure prior to storage significantly increased the susceptibility of E. coli O157:H7 to high acidity. For example, after pressure treatment, the time required for a 5-log decrease in cell numbers was reduced from 13 to 3 days at pH 3.4, from 16 to 6 days at pH 3.6, and from >25 to 8 days at pH 3.9. It is evident that the use of high-pressure processing of orange juice in order to increase the juice's shelf-life and to inactivate pathogens has the added advantage that it sensitizes E. coli O157:H7 to the high acid conditions found in orange juice, which results in the survival of significantly fewer E. coli O157:H7 during subsequent refrigerated storage.

Inactivation of Escherichia coli O157:H7 in Orange Juice Using a Combination of High Pressure and Mild Heat

1999 ◽  
Vol 62 (3) ◽  
pp. 277-279 ◽  
Author(s):  
M. LINTON ◽  
J. M. J. McCLEMENTS ◽  
M. F. PATTERSON
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Resistant Strain ◽  
Orange Juice ◽  
Escherichia Coli O157 ◽  
Pressure Treatment ◽  
Processing Conditions ◽  
E Coli ◽  
Mild Heat ◽  
Ph Range

The effect of high pressure on the survival of a pressure-resistant strain of Escherichia coli O157:H7 (NCTC 12079) in orange juice was investigated over the pH range 3.4 to 5.0. The pH of commercial, sterile orange juice was adjusted to 3.4, 3.6, 3.9, 4.5, or 5.0. The juice was then inoculated with 108 CFU ml−1 of E. coli O157:H7. The inoculated orange juice was subjected to pressure treatments of 400, 500, or 550 MPa at 20°C or 30°C to determine the conditions that would give a 6-log10 inactivation of E. coli O157:H7. A pressure treatment of 550 MPa for 5 min at 20°C produced this level of kill at pH 3.4, 3.6, 3.9, and 4.5 but not at pH 5.0. Combining pressure treatment with mild heat (30°C) did result in a 6-log10 inactivation at pH 5.0. Thus, the processing conditions (temperature and time) must be considered when pressure-treating orange juice to ensure microbiological safety.

High-Pressure Resistance Variation of Escherichia coli O157:H7 Strains and Salmonella Serovars in Tryptic Soy Broth, Distilled Water, and Fruit Juice

2007 ◽  
Vol 70 (9) ◽  
pp. 2078-2083 ◽  
Author(s):  
BROOKE M. WHITNEY ◽  
ROBERT C. WILLIAMS ◽  
JOSEPH EIFERT ◽  
JOSEPH MARCY
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Orange Juice ◽  
High Pressure Processing ◽  
Distilled Water ◽  
Escherichia Coli O157 ◽  
Bacterial Populations ◽  
E Coli ◽  
Log Reduction ◽  
Salmonella Serovars

The effect of high pressure on the log reduction of six strains of Escherichia coli O157:H7 and five serovars of Salmonella enterica was investigated in tryptic soy broth, sterile distilled water, and commercially sterile orange juice (for Salmonella) and apple cider (for E. coli). Samples were subjected to high-pressure processing treatment at 300 and 550 MPa for 2 min at 6°C. Samples were plated onto tryptic soy agar directly after pressurization and after being held for 24 h at 4°C. At 300 MPa, little effect was seen on E. coli O157:H7 strains, while Salmonella serovars varied in resistance, showing reductions between 0.26 and 3.95 log CFU/ml. At 550 MPa, E. coli O157:H7 strains exhibited a range of reductions (0.28 to 4.39 log CFU/ml), while most Salmonella populations decreased beyond the detection limit (>5-log CFU/ml reduction). The most resistant strains tested were E. coli E009 and Salmonella Agona. Generally, bacterial populations in fruit juices showed larger decreases than did populations in tryptic soy broth and distilled water. E. coli O157:H7 cultures held for 24 h at 4°C after treatment at 550 MPa showed a significant log decrease as compared with cultures directly after treatment (P ≤ 0.05), while Salmonella serovars did not show this significant decrease (P > 0.05). All Salmonella serovars tested in orange juice treated at 550 MPa for 2 min at 6°C and held for 24 h showed a >5-log decrease, while E. coli O157:H7 strains require a higher pressure, higher temperature, longer pressurization, or a chemical additive to achieve a 5-log decrease.

Inactivation of Escherichia coli in Broth and Sausage by Combined High Pressure and Lactobacillus casei Cell Extract

2010 ◽  
Vol 16 (5) ◽  
pp. 381-388 ◽  
Author(s):  
Hyun-Jung Chung ◽  
Ahmed E. Yousef
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Lactobacillus Casei ◽  
Treatment Time ◽  
Cell Extract ◽  
High Pressure Processing ◽  
Pressure Treatment ◽  
Scanning Calorimetry ◽  
E Coli ◽  
Pressure Resistance

The purpose of this study was to investigate the effect of combined high pressure and Lactobacillus casei cell extract (CE) on Escherichia coli O157 strains with variation in pressure resistance in broth and sausage. Pressure-resistant (O157:H7 and O157:H12) and -sensitive (O157-M1 and O157-M2) E. coli strains were used. Pressure treatment at 350 MPa for 20 min in broth caused 1.1-1.2 logs reduction in O157:H12 and O157:H7 and 4.1-5.5 logs reduction in the O157-M1 and O157-M2. When high pressure was treated in the presence of CE (32 CEAU/mL), the combination treatment caused a significant inactivation in the pressure-resistant O157:H7 strains resulting in the viability loss of 4.3-4.6 logs and the synergistic effect increased with increase in treatment time (p < 0.05). Similar result was observed in sausage. Differential scanning calorimetry thermogram showed that the presence of Lb. casei CE may cause considerable damage to cellular components of E. coli during the high pressure treatment. The synergy between high pressure processing and Lb. casei OSY-LB6A CE against pressure-resistant E. coli O157 strains suggests the feasibility of using this combination to minimize the risk of transmission of E. coli O157 by food.

scholarly journals Lethality Prediction for Escherichia Coli O157:H7 and Uropathogenic E. coli in Ground Chicken Treated with High Pressure Processing and Trans-Cinnamaldehyde

2018 ◽  
Vol 83 (3) ◽  
pp. 740-749 ◽  
Author(s):  
Shiowshuh Sheen ◽  
Chi-Yun Huang ◽  
Rommel Ramos ◽  
Shih-Yung Chien ◽  
O. Joseph Scullen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
High Pressure Processing ◽  
Escherichia Coli O157 ◽  
E Coli

Application of High Pressure Processing To Kill Escherichia coli O157 in Ready-to-Eat Meats

2008 ◽  
Vol 71 (11) ◽  
pp. 2182-2189 ◽  
Author(s):  
ALEXANDER O. GILL ◽  
HOSAHALLI S. RAMASWAMY
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Hold Time ◽  
Foodborne Pathogen ◽  
Immunomagnetic Separation ◽  
High Pressure Processing ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Reflected Light ◽  
Additional Reduction

Uncooked ready-to-eat (RTE) meats have previously been identified as vehicles for the transmission of the foodborne pathogen Escherichia coli O157. In this study, the potential for high pressure processing (HPP) to kill E. coli O157 in two RTE meats (Hungarian salami and All Beef salami) was investigated. The RTE meats were inoculated with a five-strain cocktail of E. coli O157, vacuum packed, and then pressure treated at 600 MPa with a hold time of 3 min. Samples were stored at 15°C for 28 days. HPP initially reduced E. coli numbers on both RTE meats by greater than 4 log CFU/g. However, with enrichment and immunomagnetic separation we were able to recover E. coli O157 from the samples. During storage, the numbers of E. coli O157 increased on the All Beef samples but remained static on the Hungarian salami, which had a restrictive pH and water activity. Increasing the hold time to 6 or 9 min did not result in additional reduction of E. coli O157. The sensory appeal of the two products was not significantly changed by HPP as determined by a sensory panel (n = 50). Analysis of the reflected light parameters of luminance, green-red, and blue-yellow revealed no significant changes. The results of these experiments indicate that HPP has potential as a lethal treatment for E. coli O157 on RTE meats with minimal changes in consumer appeal.

Use of Nonpathogenic Escherichia coli Surrogates as Predictors of the Survival of Nontyphoidal Salmonella, non-O157 Shiga Toxin–Producing Escherichia coli, and Escherichia coli O157 Populations after High Hydrostatic Pressure Processing

2018 ◽  
Vol 81 (7) ◽  
pp. 1068-1072 ◽  
Author(s):  
DALE R. WOERNER ◽  
IFIGENIA GEORNARAS ◽  
JENNIFER N. MARTIN ◽  
KEITH E. BELK ◽  
GARY R. ACUFF ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
High Pressure Processing ◽  
Escherichia Coli O157 ◽  
Specific Level ◽  
E Coli ◽  
Pathogen Populations

ABSTRACT Validated surrogates are a useful tool for studying the response of pathogens to food safety interventions, but better surrogates are needed for studies using high pressure processing. Ground beef (85% lean, 15% fat) was inoculated separately with mixed cultures of Escherichia coli O157, non-O157 Shiga toxin–producing E. coli, nontyphoidal Salmonella, and nonpathogenic E. coli surrogate bacteria. The inoculated ground beef was subjected to high hydrostatic pressures of 200, 400, and 600 MPa for 4, 6, and 8 min at each pressure. High pressure processing at 200 MPa reduced the inoculated populations of the pathogenic bacteria by 0.9 to 1.8 log CFU/g, 400 MPa reduced the inoculated populations by 2.5 to 3.6 log CFU/g, and 600 MPa reduced the inoculated populations by 4.5 to 5.6 log CFU/g. The nonpathogenic E. coli surrogates were more resistant to the effects of high pressure processing than were the inoculated pathogen populations. This finding suggests that the nonpathogenic E. coli surrogates could be used as process control indicators for high pressure processing of ground beef to predict a specific level of pathogen reduction. The surviving populations of the potential surrogate bacteria were proportional to the surviving populations of the pathogenic bacteria. The models allow for an estimation of the potential surviving populations of the pathogenic bacteria based on quantitative results of the populations of the surrogate bacteria.

Effect of Low-Temperature, High-Pressure Treatment on the Survival of Escherichia coli O157:H7 and Salmonella in Unpasteurized Fruit Juices

2001 ◽  
Vol 64 (8) ◽  
pp. 1122-1127 ◽  
Author(s):  
ALEX YEOW-LIM TEO ◽  
SADHANA RAVISHANKAR ◽  
CHARLES E. SIZER
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Low Temperature ◽  
Apple Juice ◽  
Fruit Juices ◽  
Escherichia Coli O157 ◽  
Pressure Treatment ◽  
Salmonella Spp ◽  
High Pressure Treatment ◽  
E Coli

The destructive effect of high pressure (615 MPa) combined with low temperature (15°C) on various strains of Escherichia coli O157:H7 and various serovars of Salmonella in grapefruit, orange, apple, and carrot juices was investigated. The three-strain cocktail of E. coli O157:H7 (SEA13B88, ATCC 43895, and 932) was found to be most sensitive in grapefruit juice (8.34-log reduction) and least in apple juice (0.41-log reductions) when pressurized at 615 MPa for 2 min at 15°C. Correspondingly, no injured survivor was detected in grapefruit and carrot juices under similar treatment conditions. No Salmonella spp. were detected in a 2-min pressure treatment (615 MPa, 15°C) of grapefruit and orange fruit juices. Except for Enteritidis, all four serovars tested in the present study have viability loss of between 3.92- and 5.07-log reductions when pressurized in apple juice at 615 MPa for 2 min at 15°C. No injured cells were recovered from grapefruit and orange juices, whereas the same treatment demonstrated reduction in numbers of Salmonella serovars Agona and Muenchen in apple juices and to a lesser extent with Typhimurium, Agona, and Muenchen in carrot juice. The present study demonstrated that low-temperature, high-pressure treatment has the potential to inactivate E. coli O157:H7 strains and different Salmonella spp. in different fruit juices.

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