Combined treatments of high-pressure with the lactoperoxidase system or lactoferrin on the inactivation of Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7 in beef carpaccio

2014 ◽  
Vol 41 ◽  
pp. 27-32 ◽  
Author(s):  
Daniel Bravo ◽  
María de Alba ◽  
Margarita Medina
2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
CHIA-MIN LIN ◽  
SARAH S. MOON ◽  
MICHAEL P. DOYLE ◽  
KAY H. McWATTERS

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.


2004 ◽  
Vol 67 (7) ◽  
pp. 1497-1500 ◽  
Author(s):  
Y. INATSU ◽  
M. L. BARI ◽  
S. KAWASAKI ◽  
K. ISSHIKI

The survival of gram-positive and gram-negative foodborne pathogens in both commercial and laboratory-prepared kimchi (a traditional fermented food widely consumed in Japan) was investigated. It was found that Escherichia coli O157:H7, Salmonella Enteritidis, Staphylococcus aureus, and Listeria monocytogenes could survive in both commercial and laboratory-prepared kimchi inoculated with these pathogens and incubated at 10°C for 7 days. However, when incubation was prolonged, the S. aureus level decreased rapidly from the initial inoculum level to the minimum detectable level within 12 days, whereas Salmonella Enteritidis and L. monocytogenes took 16 days to reach similar levels in commercial kimchi. On the other hand, E. coli O157:H7 remained at high levels throughout the incubation period. For laboratory-prepared kimchi, the S. aureus level decreased rapidly from the initial inoculum level to the minimum detectable level within 12 days, and L. monocytogenes took 20 days to reach a similar level. E. coli O157:H7 and Salmonella Enteritidis remained at high levels throughout the incubation period. The results of this study suggest that the contamination of kimchi with E. coli O157:H7, Salmonella Enteritidis, S. aureus, or L. monocytogenes at any stage of production or marketing could pose a potential risk.


1999 ◽  
Vol 65 (9) ◽  
pp. 4276-4279 ◽  
Author(s):  
Kumar S. Venkitanarayanan ◽  
Gabriel O. Ezeike ◽  
Yen-Con Hung ◽  
Michael P. Doyle

ABSTRACT The efficacy of electrolyzed oxidizing water for inactivatingEscherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes was evaluated. A five-strain mixture of E. coli O157:H7,S. enteritidis, or L. monocytogenes of approximately 108 CFU/ml was inoculated in 9 ml of electrolyzed oxidizing water (treatment) or 9 ml of sterile, deionized water (control) and incubated at 4 or 23°C for 0, 5, 10, and 15 min; at 35°C for 0, 2, 4, and 6 min; or at 45°C for 0, 1, 3, and 5 min. The surviving population of each pathogen at each sampling time was determined on tryptic soy agar. At 4 or 23°C, an exposure time of 5 min reduced the populations of all three pathogens in the treatment samples by approximately 7 log CFU/ml, with complete inactivation by 10 min of exposure. A reduction of ≥7 log CFU/ml in the levels of the three pathogens occurred in the treatment samples incubated for 1 min at 45°C or for 2 min at 35°C. The bacterial counts of all three pathogens in control samples remained the same throughout the incubation at all four temperatures. Results indicate that electrolyzed oxidizing water may be a useful disinfectant, but appropriate applications need to be validated.


2002 ◽  
Vol 65 (1) ◽  
pp. 100-105 ◽  
Author(s):  
KUMAR S. VENKITANARAYANAN ◽  
CHIA-MIN LIN ◽  
HANNALORE BAILEY ◽  
MICHAEL P. DOYLE

The objective of this study was to develop a practical and effective method for inactivating or substantially reducing Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on apples, oranges, and tomatoes. Apples, oranges, and tomatoes were spot-inoculated with five-strain mixtures of E. coli O157:H7, Salmonella Enteritidis, and L. monocytogenes near the stem end and were submerged in sterile deionized water containing 1.5% lactic acid plus 1.5% hydrogen peroxide for 15 min at 40°C. Inoculated samples treated with sterile deionized water at the same temperature and for the same duration served as controls. The bacterial pathogens on fruits subjected to the chemical treatment were reduced by >5.0 log10 CFU per fruit, whereas washing in deionized water decreased the pathogens by only 1.5 to 2.0 log10 CFU per fruit. Furthermore, substantial populations of the pathogens survived in the control wash water, whereas no E. coli O157:H7, Salmonella Enteritidis, or L. monocytogenes cells were detected in the chemical treatment solution. The sensory and qualitative characteristics of apples treated with the chemical wash solution were not adversely affected by the treatment. It was found that the treatment developed in this study could effectively be used to kill E. coli O157:H7, Salmonella Enteritidis, and L. monocytogenes on apples, oranges, and tomatoes at the processing or packaging level.


Sign in / Sign up

Export Citation Format

Share Document