Prior Storage Conditions Influence the Destruction of Escherichia coli O157:H7 during Heating of Apple Cider and Juice

1998 ◽  
Vol 61 (4) ◽  
pp. 390-394 ◽  
Author(s):  
STEVEN C. INGHAM ◽  
HEIDI E. ULJAS
Keyword(s):  
Escherichia Coli ◽  
Apple Juice ◽  
Storage Conditions ◽  
Escherichia Coli O157 ◽  
Strain Atcc ◽  
Linear Portion ◽  
Apple Cider ◽  
D Values ◽  
Short Time ◽  
Survivor Curve

In apple beverage manufacture, cider and juice may be stored for a short time prior to pasteurization. Storage time and temperature may affect the subsequent thermotolerance of bacteria in these beverages. This study examined whether prior storage in pH 3.4 apple cider or apple juice affected the thermotolerance of two Escherichia coli O157:H7 strains in the same beverages at 61°C. Both strains exhibited biphasic survivor curves. Strain ATCC 43894 was consistently more thermotolerant than strain ATCC 43889, with 33 to 153% greater D values derived from the linear portion of each survivor curve. Prior storage at 21°C for 2 or 6 h hastened thermal destruction of both strains in apple cider, but not to a statistically significant extent. In apple juice, prior storage at 21 °C for 2 h significantly decreased thermotolerance of strain ATCC 43889, but not of strain ATCC 43894. During 6 h of storage in 21°C apple juice, populations of strains ATCC 43889 and 43894 decreased by 2.1 and 0.5 log10 CFU/ml, respectively, and died rapidly during subsequent heating. Prior storage in apple juice at 4°C for 24 h significantly decreased thermotolerance of both strains, but this effect was not seen after 2 h of storage at 4°C. Experiments with filtered apple cider showed that presence of Alterable pulp enhanced the thermotolerance of both strains. These results show that short-term (≤6 h) room temperature storage of pH 3.4 apple cider and apple juice may enhance the lethality of subsequent pasteurization.

Inactivation of Escherichia coli O157:H7 in apple juice and apple cider by trans-cinnamaldehyde

2010 ◽  
Vol 141 (1-2) ◽  
pp. 126-129 ◽  
Author(s):  
Sangeetha Ananda Baskaran ◽  
Mary Anne Roshni Amalaradjou ◽  
Thomas Hoagland ◽  
Kumar Venkitanarayanan
Keyword(s):  
Escherichia Coli ◽  
Apple Juice ◽  
Escherichia Coli O157 ◽  
Apple Cider

Heat Inactivation of Escherichia coli O157:H7 in Apple Juice Exposed to Chlorine

2000 ◽  
Vol 63 (8) ◽  
pp. 1021-1025 ◽  
Author(s):  
JAMES P. FOLSOM ◽  
JOSEPH F. FRANK
Keyword(s):  
Escherichia Coli ◽  
Apple Juice ◽  
Thermal Inactivation ◽  
Wash Water ◽  
Heat Inactivation ◽  
Escherichia Coli O157 ◽  
Apple Cider ◽  
Time Required ◽  
Shock Proteins ◽  
Effect Of Chlorine

Exposure of Escherichia coli O157:H7 to chlorine before heat treatment results in increased production of heat shock proteins. Current heating regimens for pasteurizing apple cider do not account for chlorine exposure in the wash water. This research determined the effect of sublethal chlorine treatment on thermal inactivation of E. coli O157:H7. D58-values were calculated for stationary-phase cells exposed to 0.6 mg/liter of total available chlorine and unchlorinated cells in commercial shelf-stable apple juice (pH 3.6). D58-values for unchlorinated and chlorine-exposed cells in buffer were 5.45 and 1.65 min, respectively (P < 0.01). Death curves of chlorine-exposed and unchlorinated cells in apple juice were not completely linear. Unchlorinated cells heated in apple juice exhibit a 3-min delay before onset of linear inactivation. Chlorine treatment eliminated this shoulder, indicating an overall loss of thermotolerance. The linear portion of each curve represented a small fraction of the total population. D58-values calculated from these populations are 0.77 min for unexposed cells and 1.19 min for chlorine-exposed cells (P = 0.05). This indicates that a subpopulation of chorine-treated cells is possibly more resistant to heat because of chlorine treatment. The effect of chlorine treatment, however, is insignificant when compared with the effect of losing the shoulder. This is illustrated by the time required to kill the initial 90% of the cell population. This is observed to be 3.14 min for unchlorinated versus 0.3 min for chlorine-exposed cells (P < 0.001). These observations indicate that current heat treatments need not be adjusted for the effect of chlorine treatment.

Influence of Growth Temperature on Inactivation and Injury of Escherichia coli O157:H7 by Heat, Acid, and Freezing

1998 ◽  
Vol 61 (4) ◽  
pp. 395-401 ◽  
Author(s):  
JEFFREY J. SEMANCHEK ◽  
DAVID A. GOLDEN
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Growth Temperature ◽  
Escherichia Coli O157 ◽  
Apple Cider ◽  
C Storage ◽  
Tryptone Soya Agar ◽  
Peptone Water ◽  
Viable Population ◽  
D Values

The influence of growth temperature on heat- , lactic acid-, and freeze-induced inactivation and injury of Escherichia coli O157:H7 in 0.1% peptone water was investigated. Three strains of E. coli O157:H7 isolated respectively from salami, apple cider, and ground beef were evaluated. Growth of strains at 10°C compared with growth at 37°C had a significant impact on reducing (P < 0.01) D values obtained for heating (DH value), acid exposure (DA value), and freezing (DF value), with the exception of the cider strain stored in lactic acid Solutions. When strains were cultivated at 10 and 37°C and heated at 54 and 56°C, the salami strain possessed the highest (P < 0.01) DH values (5.9 to 59.7 min). When grown at 10°C, the beef strain had the lowest (P < 0.01) DH values after heating at 52, 54, and 56°C (11.2, 4.1, and 2.5 min, respectively). The salami strain grown at 10°C had the highest (P < 0.01) DA values in all concentrations of lactic acid. When grown at 37°C, the salami strain had the highest (P < 0.01) Da values after storage in 0.1 and 0.25% lactic acid, while DA values for the salami and beef strains did not differ (P > 0.05) when stored in 0.5% lactic acid. Portions of strain populations were sublethally injured by heat and lactic acid treatments, as evidenced by the inability of injured organisms to form colonies on tryptone soya agar containing 2% NaCl. Strains cultured at 10°C were more susceptible to sublethal heat injury than strains cultured at 37°C. Storage of test strains at −20°C for 7 months resulted in a 4- to 6-log CFU/ml reduction in viable population, but induced only minimal sublethal injury. After 5 months at −20°C, strains cultured at 10°C were more sensitive to freeze inactivation than strains cultured at 37°C. When grown at 10 and 37°C and stored at −20°C for 7 months, the cider strain possessed higher (P < 0.01) DF values than the beef and salami strains.

Inactivation of Escherichia coli O157:H7 and Other Naturally Occurring Microorganisms in Apple Cider by Electron Beam Irradiation

2004 ◽  
Vol 67 (8) ◽  
pp. 1574-1577 ◽  
Author(s):  
HUI WANG ◽  
CHERYLL A. REITMEIER ◽  
BONITA A. GLATZ
Keyword(s):  
Escherichia Coli ◽  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Escherichia Coli O157 ◽  
Beam Irradiation ◽  
Accelerator Facility ◽  
Apple Cider ◽  
E Coli ◽  
Naturally Occurring ◽  
D Values

Two Escherichia coli O157:H7 strains, SEA 13 B88 gfp 73ec and B6-914 gfp 90ec, together with two bacteria, three yeasts, and two molds that were randomly selected from a collection of microorganisms found on apples or in apple cider, were inoculated into apple cider and subjected to electron beam irradiation at several doses between 0.0 and 2.3 kGy at the Iowa State University Linear Accelerator Facility. The D-values for the E. coli O157:H7 strains ranged between 0.25 and 0.34 kGy; the D-values for most of the normal flora from apples ranged between 0.24 and 0.59 kGy. By taking into account possible variations in treatment conditions, it was calculated that irradiation at 2.47 kGy should achieve a 5-log reduction of E. coli O157:H7 in apple cider at the 95% confidence level. Naturally occurring yeasts might survive such irradiation treatment.

scholarly journals Survival of Escherichia coli O157:H7 ATCC 43895 in a Model Apple Juice Medium with Different Concentrations of Proline and Caffeic Acid

2001 ◽  
Vol 67 (6) ◽  
pp. 2863-2866 ◽  
Author(s):  
Robert D. Reinders ◽  
Steef Biesterveld ◽  
Peter G. H. Bijker
Keyword(s):  
Escherichia Coli ◽  
Caffeic Acid ◽  
Shiga Toxin ◽  
Apple Juice ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Strain Atcc ◽  
Almost All

ABSTRACT The effects of proline and caffeic acid on the survival of Shiga toxin-producing Escherichia coli (STEC) O157:H7 strain ATCC 43895 in a model apple juice medium were studied. It is hypothesized that the inhibitory effect of caffeic acid may explain why almost all outbreaks of STEC O157:H7 infections linked to apple juice or cider have occurred in October or November.

Modeling the Survival of Escherichia coli O157:H7 in Apple Cider Using Probability Distribution Functions for Quantitative Risk Assessment

2001 ◽  
Vol 64 (5) ◽  
pp. 599-605 ◽  
Author(s):  
SIOBAIN DUFFY ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Escherichia Coli ◽  
Risk Assessment ◽  
Room Temperature ◽  
Storage Conditions ◽  
Distribution Functions ◽  
Quantitative Risk Assessment ◽  
Escherichia Coli O157 ◽  
Apple Cider ◽  
E Coli ◽  
Probability Distribution Functions

Outbreaks of foodborne illness from apple cider have prompted research on the survival of Escherichia coli O157:H7 in this food. Published results vary widely, potentially due to differences in E. coli O157:H7 strains, enumeration media, and other experimental considerations. We developed probability distribution functions for the change in concentration of E. coli O157:H7 (log CFU/day) in cider using data from scientific publications for use in a quantitative risk assessment. Six storage conditions (refrigeration [4 to 5°C]; temperature abuse [6 to 10°C]; room temperature [20 to 25°C]; refrigerated with 0.1% sodium benzoate, 0.1% potassium sorbate, or both) were modeled. E. coli survival rate data for all three unpreserved cider storage conditions were highly peaked, and these data were fit to logistic distributions: ideal refrigeration, logistic (−0.061, 0.13); temperature abuse, logistic (−0.0982, 0.23); room temperature, logistic (−0.1, 0.29) and uniform (−4.3, −1.8), to model the very small chance of extremely high log CFU reductions. There were fewer published studies on refrigerated, preserved cider, and these smaller data sets were modeled with beta (4.27, 2.37) × 2.2 − 1.6, normal (−0.2, 0.13), and gamma (1.45, 0.6) distributions, respectively. Simulations were run to show the effect of storage on E. coli O157:H7 during the shelf life of apple cider. Under every storage condition, with and without preservatives, there was an overall decline in E. coli O157:H7 populations in cider, although a small fraction of the time a slight increase was seen.

Irradiation D-Values for Escherichia coli O157:H7 and Salmonella sp. on Inoculated Broccoli Seeds and Effects of Irradiation on Broccoli Sprout Keeping Quality and Seed Viability†

2003 ◽  
Vol 66 (5) ◽  
pp. 760-766 ◽  
Author(s):  
KATHLEEN T. RAJKOWSKI ◽  
GLEN BOYD ◽  
DONALD W. THAYER
Keyword(s):  
Escherichia Coli ◽  
Shelf Life ◽  
Dose Level ◽  
Germination Percentage ◽  
Yield Ratio ◽  
Escherichia Coli O157 ◽  
Broccoli Sprouts ◽  
Sprout Length ◽  
D Values ◽  
Irradiation Process

Like alfalfa sprouts, broccoli sprouts can be a vehicle for bacterial pathogens, which can cause illness when they are consumed. The gamma irradiation process was used to reduce numbers of bacterial pathogens on broccoli sprouts and seeds, and the effect of this process on the seeds was studied. The irradiation destruct values for Salmonella sp. and for strains of Escherichia coli O157:H7 inoculated on broccoli seeds were determined. Results obtained in this study indicate that a dose of 2 kGy reduced total background counts for broccoli sprouts from 106 to 107 CFU/g to 104 to 105 CFU/g and increased the shelf life of the sprouts by 10 days. Yield ratio (wt/wt), germination percentage, sprout length, and thickness were measured to determine the effects of various irradiation doses on the broccoli seeds. Results show a decreased germination percentage at a dose level of 4 kGy, whereas the yield ratio (wt/wt), sprout length, and thickness decreased at the 2-kGy dose level. The radiation doses required to inactivate Salmonella sp. and strains of E. coli O157:H7 were higher than previously reported values. D-values, dose required for a 1-log reduction, for the nonvegetable and vegetable Salmonella sp. isolates were 0.74 and 1.10 kGy, respectively. The values for the nonvegetable and vegetable isolated strains of Escherichia coli O157:H7 were 1.43 and 1.11 kGy, respectively. With the irradiation process, a dose of up to 2 kGy can extend the shelf life of broccoli sprouts. A dose of >2 kGy would have an adverse effect on the broccoli seed and decrease the yield of broccoli sprouts.

Antibacterial Effect of Monocaprylin on Escherichia coli O157:H7 in Apple Juice

2005 ◽  
Vol 68 (9) ◽  
pp. 1895-1899 ◽  
Author(s):  
MANOJ KUMAR MOHAN NAIR ◽  
HANEM ABOUELEZZ ◽  
THOMAS HOAGLAND ◽  
KUMAR VENKITANARAYANAN
Keyword(s):  
Escherichia Coli ◽  
Apple Juice ◽  
Antibacterial Effect ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
Organoleptic Properties ◽  
E Coli ◽  
Low Concentrations ◽  
Storage Temperatures ◽  
Control Samples

The antibacterial effect of low concentrations of monocaprylin on Escherichia coli O157:H7 in apple juice was investigated. Apple juice alone (control) or containing 2.5 mM (0.055%) or 5 mM monocaprylin was inoculated with a five-strain mixture of E. coli O157:H7 at ~6.0 log CFU/ml. The juice samples were stored at 23 or 4°C for 14 or 21 days, respectively, and the population of E. coli O157:H7 was determined on tryptic soy agar plates supplemented with 0.6% yeast extract. At both storage temperatures, the population of E. coli O157:H7 in monocaprylin-supplemented juice samples was significantly lower (P < 0.05) than that in the control samples. The concentration of monocaprylin and the storage temperature had a significant effect on the inactivation of E. coli O157:H7 in apple juice. Monocaprylin at 5 mM was significantly more effective than 2.5 mM monocaprylin for killing E. coli O157:H7 in apple juice. Inactivation of E. coli O157:H7 by monocaprylin was more pronounced in juice stored at 23°C than in the refrigerated samples. Results of this study indicated that monocaprylin is effective for killing E. coli O157:H7 in apple juice, but detailed sensory studies are needed to determine the organoleptic properties of apple juice containing monocaprylin.

Thermal Inactivation of Escherichia coli O157: H7, Salmonella senftenberg, and Enzymes with Potential as Time-Temperature Indicators in Ground Beef

1997 ◽  
Vol 60 (5) ◽  
pp. 471-475 ◽  
Author(s):  
ALICIA ORTA-RAMIREZ ◽  
JAMES F. PRICE ◽  
YIH-CHIH HSU ◽  
GIRIDARAN J. VEERAMUTHU ◽  
JAMIE S. CHERRY-MERRITT ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Triose Phosphate ◽  
Beef Products ◽  
Z Value ◽  
D Values ◽  
Salmonella Senftenberg

The USDA has established processing schedules for beef products based on the destruction of pathogens. Several enzymes have been suggested as potential indicators of heat processing. However, no relationship between the inactivation rates of these enzymes and those of pathogenic microorganisms has been determined. Our objective was to compare the thermal inactivation of Escherichia coli O157:H7 and Salmonella senftenberg to those of endogenous muscle proteins. Inoculated and noninoculated ground beef samples were heated at four temperatures for predetermined intervals of time in thermal-death-time studies. Bacterial counts were determined and enzymes were assayed for residual activity. The D values for E. coli O157:H7 were 46.10, 6.44, 0.43, and 0.12 min at 53, 58, 63, and 68°C, respectively, with a z value of 5.60°C. The D values for S. senftenberg were 53.00, 15.17, 2.08, and 0.22 min at 53, 58, 63, and 68°C, respectively, with a z value of 6.24°C. Apparent D values at 53, 58, 63, and 68°C were 352.93, 26.31, 5.56, and 3.33 min for acid phosphatase; 6968.64, 543.48, 19.61, and 1.40 min for lactate dehydrogenase; and 3870.97, 2678.59, 769.23, and 42.92 min for peroxidase; with z values of 7.41,3.99, and 7.80°C, respectively. Apparent D values at 53, 58, 63, and 66°C were 325.03, 60.07, 3.07, and 1.34 min for phosphoglycerate mutase; 606.72, 89.86, 4.40, and 1.28 min for glyceraldehyde-3-phosphate dehydrogenase; and 153.06, 20.13, 2.25, and 0.74 min for triose phosphate isomerase; with z values of 5.18, 4.71, and 5.56°C, respectively. The temperature dependence of triose phosphate isomerase was similar to those of both E. coli O157 :H7 and S. senftenberg, suggesting that this enzyme could be used as an endogenous time-temperature indicator in beef products.

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