Reduction of Listeria monocytogenes and Salmonella Typhimurium on Blueberries through Brief Exposure to Antimicrobial Solutions Coupled with Freezing

2019 ◽  
Vol 82 (6) ◽  
pp. 926-930 ◽  
Author(s):  
DAVID F. BRIDGES ◽  
SHRAVANI TADEPALLI ◽  
RYAN ANDERSON ◽  
RONG ZHANG ◽  
VIVIAN C. H. WU
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Acid Treatment ◽  
Frozen Storage ◽  
Short Exposure ◽  
Antimicrobial Effectiveness

ABSTRACT This study evaluated the efficacy of different brief-exposure antibacterial washes (≤3 min) coupled with frozen storage against Listeria monocytogenes and Salmonella Typhimurium on blueberries. Inoculated berries where treated with sodium hypochlorite (NaOCl, 200 ppm), chlorine dioxide (15 ppm), ozone (3 and 5 ppm), or lactic acid (2%) for short exposure times (10 s, 1 min, or 3 min), and antibacterial effectiveness was determined with or without an additional freezing hurdle (−12°C, 1 week). Wash treatments alone resulted maximum log reductions from 1.0 to 2.8, while the additional freezing step increased this to a range from 3.7 to 6.6. The greatest reduction of L. monocytogenes (6.6 log) and Salmonella Typhimurium (5.3 log) was observed after freezing combined with 3 min of exposure to 2% lactic acid or 200 ppm of NaOCl, respectfully. After treatment, no residue was measured by the methodologies used. However, lactic acid treatment resulted in changes of color and aroma. In conclusion, wash treatments of blueberries using short exposure times had antimicrobial effectiveness (1.0 to 2.8 log reductions) and can be enhanced by coupling with freezing. HIGHLIGHTS

Inhibition of Salmonella Typhimurium and Listeria monocytogenes in Mung Bean Sprouts by Chemical Treatment

2002 ◽  
Vol 65 (7) ◽  
pp. 1088-1092 ◽  
Author(s):  
SUN-YOUNG LEE ◽  
KYUNG-MI YUN ◽  
J. FELLMAN ◽  
DONG-HYUN KANG
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Mung Bean ◽  
Storage Period ◽  
Log Reduction ◽  
Mung Bean Sprouts ◽  
Chlorous Acid ◽  
Bean Sprouts

This study was undertaken to compare the efficacies of chlorous acid (268 ppm), sodium hypochlorite (200 ppm), and lactic acid (2%) in eliminating total mesophilic microorganisms, Salmonella Typhimurium, and Listeria monocytogenes on commercial mung bean sprouts immediately after treatment and during posttreatment refrigerated storage. Treatment with sodium hypochlorite for 10 min did not reduce the total aerobic count. However, treatment with lactic acid and chlorous acid for 10 min initially reduced the total aerobic count by 0.6 and 0.8 log CFU/g, respectively, and maintained the same level or a lower level of the total aerobic count during the storage time. Treatment with chlorous acid reduced Salmonella Typhimurium from 5.0 log to undetectable levels (<0.48 log CFU/g), and the pathogen remained undetectable over a 9-day storage period. Treatment with lactic acid resulted in an initial 3-log reduction and further reduced the number of Salmonella Typhimurium cells to undetectable levels after 3 days. For L. monocytogenes, treatment with chlorous acid resulted in an initial 5-log reduction, and treatment with lactic acid resulted in a 2-log reduction at the beginning and undetectable levels after 9 days. When chemically injured cells were investigated by the selective overlay method, no statistical difference was observed (P < 0.05) between the number of injured cells recovered following treatment with chlorous acid and the number of bacteria counted on selective media, whereas sodium hypochlorite generated more injured cells than the other treatments did. These data suggest that treatment with chlorous acid may be useful in reducing total mesophilic microorganisms, Salmonella Typhimurium, and L. monocytogenes in commercial mung bean sprouts.

scholarly journals Fate of Salmonella Typhimurium and Listeria monocytogenes on Whole Papaya during Storage and Antimicrobial Efficiency of Aqueous Chlorine Dioxide Generated with HCl, Malic Acid or Lactic Acid on Whole Papaya

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1871
Author(s):  
Lianger Dong ◽  
Yong Li
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Chlorine Dioxide ◽  
Malic Acid ◽  
Pathogenic Bacteria ◽  
Storage Period ◽  
Sodium Chlorite ◽  
Initial Population ◽  
Bacterial Reduction

Papaya-associated foodborne illness outbreaks have been frequently reported worldwide. The goal of this study was to evaluate the behavior of Salmonella Typhimurium and Listeria monocytogenes on whole papaya during storage and sanitizing process. Fresh green papayas were inoculated with approximately 7 log CFU of S. Typhimurium and L. monocytogenes and stored at 21 or 7 °C for 14 days. Bacteria counts were determined on day 0, 1, 7, 10 and 14. Fresh green papayas inoculated with approximately 8 log CFU of the bacteria were treated for 5 min with 2.5, 5 and 10 ppm aqueous chlorine dioxide (ClO2). The ClO2 solutions were generated by mixing sodium chlorite with an acid, which was HCl, lactic acid or malic acid. The detection limit of the enumeration method was 2.40 log CFU per papaya. At the end of storage period, S. Typhimurium and L. monocytogenes grew by 1.88 and 1.24 log CFU on papayas at 21 °C, respectively. Both bacteria maintained their initial population at inoculation on papayas stored at 7 °C. Higher concentrations of ClO2 reduced more bacteria on papaya. 10 ppm ClO2, regardless the acid used to generate the solutions, inactivated S. Typhimurium to undetectable level on papaya. 10 ppm ClO2 generated with HCl, lactic acid and malic acid reduced L. monocytogenes by 4.40, 6.54 and 8.04 log CFU on papaya, respectively. Overall, ClO2 generated with malic acid showed significantly higher bacterial reduction than ClO2 generated with HCl or lactic acid. These results indicate there is a risk of survival and growth for S. Typhimurium and L. monocytogenes on papaya at commercial storage conditions. Aqueous ClO2 generated with malic acid shows effectiveness in inactivating the pathogenic bacteria on papaya.

Influence of Catfish Skin Mucus on Trisodium Phosphate Inactivation of Attached Salmonella Typhimurium, Edwardsiella tarda, and Listeria monocytogenes

2002 ◽  
Vol 65 (7) ◽  
pp. 1146-1151 ◽  
Author(s):  
JANGHO KIM ◽  
DOUGLAS L. MARSHALL
Keyword(s):  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Antimicrobial Effect ◽  
Trisodium Phosphate ◽  
Edwardsiella Tarda ◽  
Skin Sample ◽  
Skin Mucus ◽  
Bacterial Counts ◽  
Attached Bacteria ◽  
Antimicrobial Effectiveness

This study examined the antimicrobial effectiveness of trisodium phosphate (TSP) on Edwardsiella tarda, Listeria monocytogenes, and Salmonella Typhimurium attached to catfish skin with and without mucus. Salmonella Typhimurium and E. tarda attached more readily to catfish skin than did L. monocytogenes. At high inoculum levels (107 CFU/ml), TSP treatments (at 2 to 6%) for 10 min reduced bacterial counts of E. tarda by >2.5 to >3.3 log10 CFU per skin sample for firmly attached cells and by 3.5 to 3.6 log10 CFU per skin sample for loosely attached cells. Counts of L. monocytogenes declined by 0.6 to >1.8 log10 CFU per skin sample for firmly attached cells and by 1.2 to 2.2 log10 CFU per skin sample for loosely attached cells. Counts of Salmonella Typhimurium were reduced by 3.6 to >3.8 log10 CFU per skin sample for firmly attached cells and by 3.5 to >3.8 log10 CFU per skin sample for loosely attached cells. Overall, counts of firmly attached bacteria on TSP-treated skins with mucus were higher than counts on skin without mucus. Firmly attached L. monocytogenes was more resistant to TSP than was firmly attached Salmonella Typhimurium or E. tarda. The presence of mucus on skins slightly decreased the antimicrobial effect of TSP. Significant (P < 0.05) reduction in the numbers of all three bacteria can be achieved by treatment with 6% TSP for 10 min.

Inactivation of Escherichia coli O157:H7, Salmonella Typhimurium DT104, and Listeria monocytogenes on Inoculated Alfalfa Seeds with a Fatty Acid–Based Sanitizer

2006 ◽  
Vol 69 (3) ◽  
pp. 582-590 ◽  
Author(s):  
PASCALE M. PIERRE ◽  
ELLIOT T. RYSER
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Reference Concentration ◽  
Glycerol Monolaurate ◽  
Alfalfa Seeds

Alfalfa seeds were inoculated with a three-strain cocktail of Escherichia coli O157:H7, Salmonella enterica subsp. enterica serovar Typhimurium DT104, or Listeria monocytogenes by immersion to contain ∼6 to 8 log CFU/g and then treated with a fatty acid–based sanitizer containing 250 ppm of peroxyacid, 1,000 ppm of caprylic and capric acids (Emery 658), 1,000 ppm of lactic acid, and 500 ppm of glycerol monolaurate at a reference concentration of 1×. Inoculated seeds were immersed at sanitizer concentrations of 5×, 10×, and 15× for 1, 3, 5, and 10 min and then assessed for pathogen survivors by direct plating. The lowest concentration that decreased all three pathogens by >5 log was 15×. After a 3-min exposure to the 15× concentration, populations of E. coli O157:H7, Salmonella Typhimurium DT104, and L. monocytogenes decreased by >5.45, >5.62, and >6.92 log, respectively, with no sublethal injury and no significant loss in seed germination rate or final sprout yield. The components of this 15× concentration (treatment A) were assessed independently and in various combinations to optimize antimicrobial activity. With inoculated seeds, treatment C (15,000 ppm of Emery 658, 15,000 ppm of lactic acid, and 7,500 ppm of glycerol monolaurate) decreased Salmonella Typhimurium, E. coli O157:H7, and L. monocytogenes by 6.23 and 5.57 log, 4.77 and 6.29 log, and 3.86 and 4.21 log after 3 and 5 min of exposure, respectively. Treatment D (15,000 ppm of Emery 658 and 15,000 ppm of lactic acid) reduced Salmonella Typhimurium by >6.90 log regardless of exposure time and E. coli O157:H7 and L. monocytogenes by 4.60 and >5.18 log and 3.55 and 3.14 log after 3 and 5 min, respectively. No significant differences (P > 0.05) were found between treatments A, C, and D. Overall, treatment D, which contained Emery 658 and lactic acid as active ingredients, reduced E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes populations by 3.55 to >6.90 log and may provide a viable alternative to the recommended 20,000 ppm of chlorine for sanitizing alfalfa seeds.

Heat Shock and Cold Shock Treatments Affect the Survival of Listeria monocytogenes and Salmonella Typhimurium Exposed to Disinfectants

2012 ◽  
Vol 75 (4) ◽  
pp. 695-700 ◽  
Author(s):  
MENG-HSUAN LIN ◽  
MING-LUN CHIANG ◽  
CHORNG-LIANG PAN ◽  
CHENG-CHUN CHOU
Keyword(s):  
Listeria Monocytogenes ◽  
Heat Shock ◽  
Salmonella Typhimurium ◽  
Chlorine Dioxide ◽  
Quaternary Ammonium ◽  
Cold Shock ◽  
Test Organism ◽  
Exposure Period ◽  
Quaternary Ammonium Compounds ◽  
Ammonium Compounds

The foodborne pathogens Listeria monocytogenes and Salmonella Typhimurium were subjected to heat shock at 48°C for 10 and 30 min, respectively, and then cold shocked at 15°C for 3 h. The effect of these shocks on the viability of test organisms exposed to chlorine dioxide and quaternary ammonium compounds was then determined. After exposure to the disinfectants, the viable population of each test organism, regardless of heat shock or cold shock treatment, decreased as the exposure period was extended. Both heat shock and cold shock treatments reduced the susceptibility of L. monocytogenes to both disinfectants at 25°C. However, for Salmonella Typhimurium, exposure to the chlorine dioxide disinfectant or quaternary ammonium compounds at 25°C significantly reduced (P < 0.05) survival of heat-shocked cells but significantly increased (P < 0.05) survival of cold-shocked cells compared with control cells. Survival of both L. monocytogenes and Salmonella Typhimurium generally was reduced after exposure to disinfectants at 40°C compared with 25°C.

scholarly journals Inactivation of Enterohemorrhagic Escherichia coli in Rumen Content- or Feces-Contaminated Drinking Water for Cattle

2006 ◽  
Vol 72 (5) ◽  
pp. 3268-3273 ◽  
Author(s):  
Tong Zhao ◽  
Ping Zhao ◽  
Joe W. West ◽  
John K. Bernard ◽  
Heath G. Cross ◽  
...  
Keyword(s):  
Drinking Water ◽  
Lactic Acid ◽  
Chlorine Dioxide ◽  
Caprylic Acid ◽  
Acid Treatment ◽  
Calcium Sulfate ◽  
Rumen Content ◽  
E Coli ◽  
Water Treatments ◽  
On Farm

ABSTRACT Cattle drinking water is a source of on-farm Escherichia coli O157:H7 transmission. The antimicrobial activities of disinfectants to control E. coli O157:H7 in on-farm drinking water are frequently neutralized by the presence of rumen content and manure that generally contaminate the drinking water. Different chemical treatments, including lactic acid, acidic calcium sulfate, chlorine, chlorine dioxide, hydrogen peroxide, caprylic acid, ozone, butyric acid, sodium benzoate, and competing E. coli, were tested individually or in combination for inactivation of E. coli O157:H7 in the presence of rumen content. Chlorine (5 ppm), ozone (22 to 24 ppm at 5�C), and competing E. coli treatment of water had minimal effects (<1 log CFU/ml reduction) on killing E. coli O157:H7 in the presence of rumen content at water-to-rumen content ratios of 50:1 (vol/wt) and lower. Four chemical-treatment combinations, including (i) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.05% caprylic acid (treatment A); (ii) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.1% sodium benzoate (treatment B); (iii) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.5% butyric acid (treatment C); and (iv) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 100 ppm chlorine dioxide (treatment D); were highly effective (>3 log CFU/ml reduction) at 21�C in killing E. coli O157:H7, O26:H11, and O111:NM in water heavily contaminated with rumen content (10:1 water/rumen content ratio [vol/wt]) or feces (20:1 water/feces ratio [vol/wt]). Among them, treatments A, B, and C killed >5 log CFU E. coli O157:H7, O26:H11, and O111:NM/ml within 30 min in water containing rumen content or feces, whereas treatment D inactivated approximately 3 to 4 log CFU/ml under the same conditions. Cattle given water containing treatment A or C or untreated water (control) ad libitum for two 7-day periods drank 15.2, 13.8, and 30.3 liters/day, respectively, and cattle given water containing 0.1% lactic acid plus 0.9% acidic calcium sulfate (pH 2.1) drank 18.6 liters/day. The amounts of water consumed for all water treatments were significantly different from that for the control, but there were no significant differences among the water treatments. Such treatments may best be applied periodically to drinking water troughs and then flushed, rather than being added continuously, to avoid reduced water consumption by cattle.

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