EFFECT OF LACTIC ACID ON Escherichia coli O157:H7 AND ON COLOR STABILITY OF VACUUM-PACKAGED BEEF STEAKS UNDER HIGH STORAGE TEMPERATURE

Mechanical tenderization improves the palatability of beef; however, it increases the risk of translocating pathogenic bacteria to the interior of beef cuts. This study investigated the efficacies of lactic acid spray (LA; 5%), storage, and cooking on the survivability of Escherichia coli O157:H7 in mechanically tenderized beef steaks managed under simulated industry conditions. Beef subprimals inoculated with either high (105 CFU/ml) or low (103 CFU/ml) levels of E. coli O157:H7 were treated (LA or control) and stored for 21 days prior to mechanical tenderization, steak portioning (2.54 cm), and additional storage for 7 days. Steaks were then cooked to an internal temperature of 55, 60, 65, 70, or 75°C. Samples were enumerated and analyzed using DNA-based methods. Treatment with LA immediately reduced E. coli O157:H7 on the lean and fat surfaces of high- and low-inoculum–treated subprimals by more than 1.0 log CFU/cm2 (P < 0.05). Storage for 21 days reduced surface populations of E. coli O157:H7 regardless of the inoculation level; however, the populations on LA- and control-treated lean surfaces of high- and low-inoculum–treated subprimals were not different after 21 days (P > 0.05). E. coli O157:H7 was detected in core samples from high-inoculum–treated steaks cooked to 55, 60, or 70°C. Conversely, E. coli O157:H7 was not detected in core samples from low-inoculum–treated steaks, regardless of the internal cooking temperature. These data suggest that LA- and storage-mediated reduction of pathogens on subprimals exposed to typical industry contamination levels (101 CFU/cm2) reduces the risk of pathogen translocation and subsequent survival after cooking.

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Hydrothermic Treatment Effects on Some Ripening Changes on Mango Fruits (Mangifera indica L) Crillo de Bocado' during Storage: I. Physical Parameters

HortScience ◽

10.21273/hortsci.33.3.520d ◽

1998 ◽

Vol 33 (3) ◽

pp. 520d-520

Author(s):

Oswaldo Valor ◽

Juan E Manzano

Keyword(s):

Weight Loss ◽

Skin Color ◽

Storage Temperature ◽

Mangifera Indica ◽

Physical Parameters ◽

Fresh Weight ◽

Randomized Design ◽

High Storage Temperature ◽

High Storage ◽

Green Stage

Mango fruits `Criollo de Bocado' harvested at the mature-green stage were treated with a hydrothermic treatment of 55 °C for 3 min and stored for 20 days to temperatures of 10 ± 2, 15 ± 2, and 28 ± 2 °C. A randomized design 2 × 3 × 4 with three replications was used. Physical parameters such as color (L*, a*, b*), firmnness, and fresh weight loss were studied. Results reported that mango fruits stored at 10.2 and 15.2 °C showed the highest firmness values. Skin color changed very fast during the first storage days, while pulp color required more time to achieve mature ripe color. Fresh weight loss tended to increase with storage time and with high storage temperature. The lowest storage temperture retarded softening in mango fruits and firmnness reached the highest values.

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Lactic acid bacteria biofilms and their ability to mitigate Escherichia coli O157:H7 surface colonization

Letters in Applied Microbiology ◽

10.1111/lam.13509 ◽

2021 ◽

Author(s):

L Cisneros ◽

N Cattelan ◽

MI Villalba ◽

C. Rodriguez ◽

DO Serra ◽

...

Keyword(s):

Escherichia Coli ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Escherichia Coli O157 ◽

Surface Colonization

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Effects of Water Source, Dilution, Storage, and Bacterial and Fecal Loads on the Efficacy of Electrolyzed Oxidizing Water for the Control of Escherichia coli O157:H7

Journal of Food Protection ◽

10.4315/0362-028x-67.7.1377 ◽

2004 ◽

Vol 67 (7) ◽

pp. 1377-1383 ◽

Cited By ~ 13

Author(s):

S. M. L. STEVENSON ◽

S. R. COOK ◽

S. J. BACH ◽

T. A. McALLISTER

Keyword(s):

Escherichia Coli ◽

Bactericidal Activity ◽

Storage Temperature ◽

Uv Light ◽

Tap Water ◽

Organic Matter Content ◽

Water Source ◽

Deionized Water ◽

Escherichia Coli O157 ◽

E Coli

To evaluate the potential of using electrolyzed oxidizing (EO) water for controlling Escherichia coli O157:H7 in water for livestock, the effects of water source, electrolyte concentration, dilution, storage conditions, and bacterial or fecal load on the oxidative reduction potential (ORP) and bactericidal activity of EO water were investigated. Anode and combined (7:3 anode:cathode, vol/vol) EO waters reduced the pH and increased the ORP of deionized water, whereas cathode EO water increased pH and lowered ORP. Minimum concentrations (vol/vol) of anode and combined EO waters required to kill 104 CFU/ml planktonic suspensions of E. coli O157:H7 strain H4420 were 0.5 and 2.0%, respectively. Cathode EO water did not inhibit H4420 at concentrations up to 16% (vol/vol). Higher concentrations of anode or combined EO water were required to elevate the ORP of irrigation or chlorinated tap water compared with that of deionized water. Addition of feces to EO water products (0.5% anode or 2.0% combined, vol/vol) significantly reduced (P < 0.001) their ORP values to <700 mV in all water types. A relationship between ORP and bactericidal activity of EO water was observed. The dilute EO waters retained the capacity to eliminate a 104 CFU/ml inoculation of E. coli O157:H7 H4420 for at least 70 h regardless of exposure to UV light or storage temperature (4 versus 24°C). At 95 h and beyond, UV exposure reduced ORP, significantly more so (P < 0.05) in open than in closed containers. Bactericidal activity of EO products (anode or combined) was lost in samples in which ORP value had fallen to ≤848 mV. When stored in the dark, the diluted EO waters retained an ORP of >848 mV and bactericidal efficacy for at least 125 h; with refrigeration (4°C), these conditions were retained for at least 180 h. Results suggest that EO water may be an effective means by which to control E. coli O157:H7 in livestock water with low organic matter content.

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Fate of Escherichia coli O157:H7 and Other Coliforms in Commercial Mayonnaise and Refrigerated Salad Dressing

Journal of Food Protection ◽

10.4315/0362-028x-58.1.13 ◽

1995 ◽

Vol 58 (1) ◽

pp. 13-18 ◽

Cited By ~ 46

Author(s):

ERROL V. RAGHUBEER ◽

JIM S. KE ◽

MICHAEL L. CAMPBELL ◽

RICHARD S. MEYER

Keyword(s):

Escherichia Coli ◽

Storage Temperature ◽

Enterobacter Aerogenes ◽

Antimicrobial Effect ◽

Coliform Bacteria ◽

Escherichia Coli O157 ◽

Salad Dressing ◽

E Coli ◽

Survival Pattern ◽

High Level

Commercial mayonnaise and refrigerated ranch salad dressing were inoculated at two levels with two strains of Escherichia coli O157:H7, a non-pathogenic E. coli, and the non-fecal coliform Enterobacter aerogenes. Results showed that at the high inoculation level (>106 colony forming units [CFU]/g) in mayonnaise stored at room temperature (ca. 22°C) both strains of O157:H7 were undetected at 96 h. At the high inoculation level, all strains of coliform bacteria tested survived longer in salad dressing stored at 4°C than in mayonnaise stored at 22°C. The O157:H7 strains were still present at low levels after 17 days. The survival time in the low-level inoculum (104CFU/g) study decreased, but the survival pattern in the two products was similar to that observed in the high-level inoculum study. Slight differences in survival among strains were observed. The greater antimicrobial effect of mayonnaise may be attributable to differences in pH, water activity (aw), nutrients, storage temperature, and the presence of lysozyme in the whole eggs used in the production of commercial mayonnaise. Coliform bacteria survived longer in refrigerated salad dressing than in mayonnaise particularly at the high-level inoculum. Both mayonnaise (pH 3.91) and salad dressing (pH 4.51) did not support the growth of any of the microorganisms even though survival was observed.

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

Journal of Food Protection ◽

10.4315/0362-028x-68.9.1895 ◽

2005 ◽

Vol 68 (9) ◽

pp. 1895-1899 ◽

Cited By ~ 10

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.

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Corrigendum to “Inhibition of in vitro growth of Shiga toxin-producing Escherichia coli O157:H7 by probiotic Lactobacillus strains due to production of lactic acid”[Int. J. Food Microbiol. 68 (2001) 135–140]

International Journal of Food Microbiology ◽

10.1016/s0168-1605(02)00036-3 ◽

2002 ◽

Vol 74 (1-2) ◽

pp. 167

Author(s):

Michinaga Ogawa ◽

Kensuke Shimizu ◽

Koji Nomoto ◽

Ryuichiro Tanaka ◽

Takashi Hamabata ◽

...

Keyword(s):

Escherichia Coli ◽

Lactic Acid ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

In Vitro Growth ◽

Probiotic Lactobacillus

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Relative gene expression in acid-adapted Escherichia coli O157:H7 during lactoperoxidase and lactic acid challenge in Tryptone Soy Broth

Microbiological Research ◽

10.1016/j.micres.2009.11.003 ◽

2010 ◽

Vol 165 (7) ◽

pp. 546-556 ◽

Cited By ~ 11

Author(s):

Angela A. Parry-Hanson ◽

Piet J. Jooste ◽

Elna M. Buys

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Lactic Acid ◽

Escherichia Coli O157 ◽

Relative Gene Expression ◽

Relative Gene ◽

Acid Challenge

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Inactivation of Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, and Listeria monocytogenes on Lettuce by Hydrogen Peroxide and Lactic Acid and by Hydrogen Peroxide with Mild Heat

Journal of Food Protection ◽

10.4315/0362-028x-65.8.1215 ◽

2002 ◽

Vol 65 (8) ◽

pp. 1215-1220 ◽

Cited By ~ 107

Author(s):

CHIA-MIN LIN ◽

SARAH S. MOON ◽

MICHAEL P. DOYLE ◽

KAY H. McWATTERS

Keyword(s):

Escherichia Coli ◽

Hydrogen Peroxide ◽

Lactic Acid ◽

Listeria Monocytogenes ◽

Salmonella Enterica ◽

Salmonella Enteritidis ◽

Sensory Characteristics ◽

Escherichia Coli O157 ◽

E Coli ◽

Log Reduction

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.

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