Survival of Salmonella Typhimurium and Escherichia coli O157 : H7 on blueberries and impacts on berry quality during 12 weeks of frozen storage after washing with combinations of sodium dodecyl sulfate and organic acids or hydrogen peroxide

2021 ◽  
Author(s):  
Yingying Li ◽  
Changqing Wu
2009 ◽  
Vol 72 (5) ◽  
pp. 928-936 ◽  
Author(s):  
TONG ZHAO ◽  
PING ZHAO ◽  
MICHAEL P. DOYLE

Four organic acids (lactic acid, acetic acid, caprylic acid, and levulinic acid) and sodium dodecyl sulfate (SDS) were evaluated individually or in combination for their ability to inactivate Salmonella and Escherichia coli O157:H7. Results from pure culture assays in water with the treatment chemical revealed that 0.5% organic acid and 0.05 to 1% SDS, when used individually, reduced pathogen cell numbers by ≤2 log CFU/ml within 20 min at 21°C. The combination of any of these organic acids at 0.5% with 0.05% SDS resulted in >7 log CFU/ml inactivation of Salmonella and E. coli O157:H7 within 10 s at 21°C. A combination of levulinic acid and SDS was evaluated at different concentrations for pathogen reduction on lettuce at 21°C, on poultry (wings and skin) at 8°C, and in water containing chicken feces or feathers at 21°C. Results revealed that treatment of lettuce with a combination of 3% levulinic acid plus 1% SDS for <20 s reduced both Salmonella and E. coli O157:H7 populations by >6.7 log CFU/g on lettuce. Salmonella and aerobic bacterial populations on chicken wings were reduced by >5 log CFU/g by treatment with 3% levulinic acid plus 2% SDS for 1 min. Treating water heavily contaminated with chicken feces with 3% levulinic acid plus 2% SDS reduced Salmonella populations by >7 log CFU/ml within 20 s. The use of levulinic acid plus SDS as a wash solution may have practical application for killing foodborne enteric pathogens on fresh produce and uncooked poultry.


2010 ◽  
Vol 73 (11) ◽  
pp. 2010-2017 ◽  
Author(s):  
TONG ZHAO ◽  
PING ZHAO ◽  
MICHAEL P. DOYLE

Studies were conducted to determine the best concentration and exposure time for treatment of alfalfa seeds with levulinic acid plus sodium dodecyl sulfate (SDS) to inactivate Escherichia coli O157:H7 and Salmonella without adversely affecting seed germination. Alfalfa seeds inoculated with a five-strain mixture of E. coli O157:H7 or Salmonella Typhimurium were dried in a laminar flow hood at 21°C for up to 72 h. Inoculated alfalfa seeds dried for 4 h then treated for 5 min at21°C with 0.5% levulinic acid and 0.05% SDS reduced the population of E. coli O157:H7 and Salmonella Typhimurium by 5.6 and 6.4 log CFU/g, respectively. On seeds dried for 72 h, treatment with 0.5% levulinic acid and 0.05% SDS for 20 min at 21°C reduced E. coli O157:H7 and Salmonella Typhimurium populations by 4 log CFU/g. Germination rates of alfalfa seeds treated with 0.5% levulinic acid plus 0.05% SDS for up to 1 h at 21°C were compared with a treatment of 20,000 ppm of calcium hypochlorite or tap water only. Treatment of alfalfa seeds with 0.5% levulinic acid plus 0.05% SDS for 5 min at 21°C resulted in a >3.0-log inactivation of E. coli O157:H7 and Salmonella.


2014 ◽  
Vol 77 (4) ◽  
pp. 528-537 ◽  
Author(s):  
TONG ZHAO ◽  
PING ZHAO ◽  
DONG CHEN ◽  
RAVIRAJSINH JADEJA ◽  
YEN-CON HUNG ◽  
...  

Studies were done at 21°C to determine the bactericidal activity of lactic acid, levulinic acid, and sodium dodecyl sulfate (SDS) applied individually and in combination on Shiga toxin–producing Escherichia coli (STEC) in pure culture and to compare the efficacy of lactic acid and levulinic acid plus SDS treatments applied by spray or immersion to inactivate STEC and Salmonella (107 CFU/cm2) on beef trim pieces (10 by 10 by 7.5 cm). Application of 3% lactic acid for 2 min to pure cultures was shown to reduce E. coli O26:H11, O45:H2, O111:H8, O103:H2, O121:H2, O145:NM, and O157:H7 populations by 2.1, 0.4, 0.3, 1.4, 0.3, 2.1, and 1.7 log CFU/ml, respectively. Treatment with 0.5% levulinic acid plus 0.05% SDS for <1 min reduced the populations of all STEC strains to undetectable levels (>6 log/ml reduction). Beef surface temperature was found to affect the bactericidal activity of treatment with 3% levulinic acid plus 2% SDS (LV-SDS). Treating cold (4°C) beef trim with LV-SDS at 21, 62, or 81°C for 30 s reduced E. coli O157:H7 by 1.0, 1.1, or 1.4 log CFU/cm2, respectively, whereas treating beef trim at 8°C with LV-SDS at 12°C for 0.1, 1, 3, or 5 min reduced E. coli O157:H7 by 1.4, 2.4, 2.5, or 3.3 log CFU/cm2, respectively. Spray treatment of beef trim at 4°C with 5% lactic acid only reduced the E. coli O157:H7 population by 1.3 log CFU/cm2. Treating beef trim at 8°C with LV-SDS for 1, 2, or 3 min reduced Salmonella Typhimurium by 2.1, 2.6, and >5.0 log CFU/cm2, respectively. Hand massaging the treated beef trim substantially reduced contamination of both pathogens, with no detectable E. coli O157:H7 or Salmonella Typhimurium (<5 CFU/cm2) on beef trim pieces treated with LV-SDS. Reduction of E. coli O157:H7 and Salmonella Typhimurium populations was enhanced, but bactericidal activity was affected by the meat temperature.


2013 ◽  
Vol 10 (7) ◽  
pp. 661-663 ◽  
Author(s):  
Mohamed G. Elramady ◽  
Sharif S. Aly ◽  
Paul V. Rossitto ◽  
Jennifer A. Crook ◽  
James S. Cullor

2011 ◽  
Vol 74 (1) ◽  
pp. 140-144 ◽  
Author(s):  
YNES R. ORTEGA ◽  
MARIA P. TORRES ◽  
JESSICA M. TATUM

Foodborne parasites are characterized as being highly resistant to sanitizers used by the food industry. In 2009, a study reported the effectiveness of levulinic acid in combination with sodium dodecyl sulfate (SDS) in killing foodborne bacteria. Because of their innocuous properties, we studied the effects of levulinic acid and SDS at various concentrations appropriate for use in foods, on the viability of Cryptosporidium parvum and Encephalitozoon intestinalis. The viability of Cryptosporidium and E. intestinalis was determined by in vitro cultivation using the HCT-8 and RK-13 cell lines, respectively. Two Escherichia coli O157:H7 isolates were also used in the present study: strain 932 (a human isolate from a 1992 Oregon meat outbreak) and strain E 0018 (isolated from calf feces). Different concentrations and combinations of levulinic acid and SDS were tested for their ability to reduce infectivity of C. parvum oocysts (105), E. intestinalis spores (106), and E. coli O157:H7 (107/ml) when in suspension. Microsporidian spores were treated for 30 and 60 min at 20 ± 2°C. None of the combinations of levulinic acid and SDS were effective at inactivating the spores or oocysts. When Cryptosporidium oocysts were treated with higher concentrations (3% levulinic acid–2% SDS and 2% levulinic acid–1% SDS) for 30, 60, and 120 min, viability was unaffected. E. coli O157:H7, used as a control, was highly sensitive to the various concentrations and exposure times tested. SDS and levulinic acid alone had very limited effect on E. coli O157:H7 viability, but in combination they were highly effective at 30 and 60 min of incubation. In conclusion, Cryptosporidium and microsporidia are not inactivated when treated for various periods of time with 2% levulinic acid–1% SDS or 3% levulinic acid–2% SDS at 20°C, suggesting that this novel sanitizer cannot be used to eliminate parasitic contaminants in foods.


Food Control ◽  
2017 ◽  
Vol 71 ◽  
pp. 79-82 ◽  
Author(s):  
Hajime Takahashi ◽  
Yun Gao ◽  
Satoko Miya ◽  
Takashi Kuda ◽  
Bon Kimura

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