scholarly journals Inactivation effect of UV-C and mild heat treatment against Salmonella Typhimurium and Escherichia coli O157:H7 on black pepper powder

2018 ◽  
Vol 28 (2) ◽  
pp. 599-607 ◽  
Author(s):  
Mi-Jung Park ◽  
Jin-Hee Kim ◽  
Se-Wook Oh
Keyword(s):  
Escherichia Coli ◽  
Heat Treatment ◽  
Salmonella Typhimurium ◽  
Black Pepper ◽  
Escherichia Coli O157 ◽  
Mild Heat ◽  
Pepper Powder ◽  
Uv C ◽  
Black Pepper Powder ◽  
Inactivation Effect

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black pepper and red pepper by gamma irradiation

2014 ◽  
Vol 172 ◽  
pp. 125-129 ◽  
Author(s):  
Won-Jae Song ◽  
Hye-Jung Sung ◽  
Sung-Youn Kim ◽  
Kwang-Pyo Kim ◽  
Sangryeol Ryu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Gamma Irradiation ◽  
Black Pepper ◽  
Red Pepper ◽  
Escherichia Coli O157

Nucleic Acid Persistence in Heat-Killed Escherichia coli O157:H7 from Contaminated Skim Milk†

1999 ◽  
Vol 62 (8) ◽  
pp. 839-844 ◽  
Author(s):  
JOHN L. MCKILLIP ◽  
LEE-ANN JAYKUS ◽  
MARYANNE DRAKE
Keyword(s):  
Escherichia Coli ◽  
Heat Treatment ◽  
Nucleic Acid ◽  
Dna Sequences ◽  
Skim Milk ◽  
Escherichia Coli O157 ◽  
Rt Pcr ◽  
Lower Efficiency ◽  
Time Points ◽  
Mild Heat

Polymerase chain reaction (PCR) and reverse transcriptase (RT)-PCR using primers targeting 16S rRNA sequences in Escherichia coli O157:H7 were applied to monitor the stability of rDNA and rRNA in cells killed by mild heat treatment (60°C) in skim milk. Serial dilutions of purified RNA and DNA from E. coli 0157:H7 in skim milk were amplified by RT-PCR or PCR, respectively, before heat treatment and at time points 0, 6, 12, 24, and 48 h after heating. In general, DNA-PCR provided stronger amplification signals compared to RT-PCR at the corresponding time points with the same PCR primer set, indicating a lower efficiency of RNA amplification compared to that of DNA. Ribosomal RNA and rDNA could be amplified by RT-PCR or PCR from both viable and dead cells throughout the 48-h posttreatment holding period. For RT-PCR, amplification signals decreased in intensity with increased holding time, while the efficiency of amplification of DNA sequences from dead cells remained fairly stable throughout the study. DNA persistence was greater than that of rRNA following cell death by mild heat treatment in skim milk. Skim milk did not appear to accelerate nucleic acid degradation. While rRNA was less stable than DNA, its detection by RT-PCR may not be appropriate as an exclusive indicator of cell viability in minimally processed foods.

Efficiency of Sodium Hypochlorite, Fumaric Acid, and Mild Heat in Killing Native Microflora and Escherichia coli O157:H7, Salmonella Typhimurium DT104, and Staphylococcus aureus Attached to Fresh-Cut Lettuce

2006 ◽  
Vol 69 (2) ◽  
pp. 323-329 ◽  
Author(s):  
NOZOMI KONDO ◽  
MASATSUNE MURATA ◽  
KENJI ISSHIKI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Fumaric Acid ◽  
Bacterial Flora ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Mild Heat ◽  
Log Reduction

The effect of the disinfectant sodium hypochlorite (NaClO), with or without mild heat (50°C) and fumaric acid, on native bacteria and the foodborne pathogens Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella Typhimurium DT104 attached to iceberg lettuce leaves was examined. The retail lettuce examined consistently harbored 6 to 7 log CFU/g of native bacteria throughout the study period. Inner leaves supported 1 to 2 log CFU/g fewer bacteria than outer leaves. About 70% of the native bacterial flora was removed by washing five times with 0.85% NaCl. S. aureus, E. coli, and Salmonella allowed to attach to lettuce leaves for 5 min were more easily removed by washing than when allowed to attach for 1 h or 2 days, with more S. aureus being removed than E. coli or Salmonella Typhimurium. An increase of time for attachment of pathogens from 5 min to 2 days leads to decreased efficiency of the washing and sanitizing treatment. Treatment with fumaric acid (50 mM for 10 min at room temperature) was the most effective, although it caused browning of the lettuce, with up to a 2-log reduction observed. The combination of 200 ppm of sodium hypochlorite and mild heat treatment at 50°C for 1 min reduced the pathogen populations by 94 to 98% (1.2- to 1.7-log reduction) without increasing browning.

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