Control of Listeria monocytogenes with Combined Antimicrobials on Beef Franks Stored at 4°C

2004 ◽  
Vol 67 (10) ◽  
pp. 2296-2301 ◽  
Author(s):  
MILAGROS UHART ◽  
SADHANA RAVISHANKAR ◽  
NICOLE D. MAKS
Keyword(s):  
Listeria Monocytogenes ◽  
Safety Issue ◽  
Meat Products ◽  
Sodium Lactate ◽  
Meat Processing ◽  
Bacterial Strains ◽  
Log Reduction ◽  
Sodium Diacetate ◽  
Packaged Beef ◽  
Antimicrobial Treatments

Contamination of ready-to-eat meat products such as beef franks with Listeria monocytogenes has become a major concern for the meat processing industry and an important food safety issue. The objective of this study was to determine the effectiveness of combinations of antimicrobials as aqueous dipping solutions to control L. monocytogenes on vacuum-packaged beef franks stored at 4°C for 3 weeks. Commercial beef franks were dipped for 5 min in three antimicrobial solutions: pediocin (6,000 AU), 3% sodium diacetate and 6% sodium lactate combined, and a combination of the three antimicrobials. Samples were then inoculated with 107 CFU/g of either four L. monocytogenes strains individually or a cocktail of the four strains, vacuum packaged, and stored at 4°C for 3 weeks. Sampling was carried out at day 0 and after 2 and 3 weeks of storage. Individual strains, as well as the cocktail, exhibited different responses to the antimicrobial treatments. After 2 and 3 weeks of storage at 4°C, pediocin-treated beef franks showed a less than 1-log reduction for all bacterial strains. Samples treated with the sodium diacetate–sodium lactate combination showed about a 1-log reduction after 2 weeks of storage for all strains and between a 1- and 2-log reduction after 3 weeks of storage, depending on the bacterial strain. When the three antimicrobials were combined, reductions ranged between 1 and 1.5 log units and 1.5 to 2.5 log units after 2 and 3 weeks of storage, respectively, at 4°C. These results indicate that the use of combined antimicrobial solutions for dipping treatments is more effective at inhibiting L. monocytogenes than treatments using antimicrobials such as pediocin separately.

Antimicrobials in the Formulation To Control Listeria monocytogenes Postprocessing Contamination on Frankfurters Stored at 4°C in Vacuum Packages

2001 ◽  
Vol 64 (12) ◽  
pp. 1949-1955 ◽  
Author(s):  
GERARD K. BEDIE ◽  
JOHN SAMELIS ◽  
JOHN N. SOFOS ◽  
KEITH E. BELK ◽  
JOHN A. SCANGA ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Acetate ◽  
Meat Products ◽  
Sodium Lactate ◽  
Pure Substance ◽  
Product Packaging ◽  
Complete Control ◽  
C Storage ◽  
Control Growth ◽  
Sodium Diacetate

Postprocessing contamination of cured meat products with Listeria monocytogenes during slicing and packaging is difficult to avoid, and thus, hurdles are needed to control growth of the pathogen during product storage. This study evaluated the influence of antimicrobials, included in frankfurter formulations, on L. monocytogenes populations during refrigerated (4°C) storage of product inoculated (103 to 104 CFU/cm2) after peeling of casings and before vacuum packaging. Frankfurters were prepared to contain (wt/wt) sodium lactate (3 or 6%, as pure substance of a liquid, 60% wt/wt, commercial product), sodium acetate (0.25 or 0.5%), or sodium diacetate (0.25 or 0.5%). L. monocytogenes populations (PALCAM agar and Trypticase soy agar plus 0.6% yeast extract [TSAYE]) exceeded 106 CFU/cm2 in inoculated controls at 20 days of storage. Sodium lactate at 6% and sodium diacetate at 0.5% were bacteriostatic, or even bactericidal, throughout storage (120 days). At 3%, sodium lactate prevented pathogen growth for at least 70 days, while, in decreasing order of effectiveness, sodium diacetate at 0.25% and sodium acetate at 0.5 and 0.25% inhibited growth for 20 to 50 days. Antimicrobials had no effect on product pH, except for sodium diacetate at 0.5%, which reduced the initial pH by approximately 0.4 U. These results indicate that concentrations of sodium acetate currently permitted by the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) (0.25%) or higher (0.5%) may control growth of L. monocytogenes for approximately 30 days, while currently permitted levels of sodium lactate (3%) and sodium diacetate (0.25%) may be inhibitory for 70 and 35 to 50 days, respectively. Moreover, levels of sodium lactate (6%) or sodium diacetate (0.5%) higher than those presently permitted by the USDA-FSIS may provide complete control at 4°C of growth (120 days) of L. monocytogenes introduced on the surface of frankfurters during product packaging.

Protein Variations in Listeria monocytogenes Exposed to Sodium Lactate, Sodium Diacetate, and Their Combination

2007 ◽  
Vol 70 (1) ◽  
pp. 58-64 ◽  
Author(s):  
EVELYNE MBANDI ◽  
BRETT S. PHINNEY ◽  
DOUGLAS WHITTEN ◽  
LEORA A. SHELEF
Keyword(s):  
Listeria Monocytogenes ◽  
Meat Products ◽  
Defined Medium ◽  
Sodium Lactate ◽  
Salt Treatment ◽  
Adverse Conditions ◽  
Novel Proteins ◽  
Proteomic Approach ◽  
Salts Of Organic Acids ◽  
Sodium Diacetate

Most studies of the effect of adverse conditions on survival of Listeria monocytogenes have focused on stress caused by acid or sodium chloride. However, no information is available on resistance of this pathogen to stress caused by salts of organic acids. Sodium lactate and sodium diacetate are generally recognized as safe substances and are approved as ingredients for use in foods. We evaluated antilisterial properties of each of these salts and the enhanced inhibition effected by their combination in ready-to-eat meat products at pH 6.3. Changes in proteins found in this pathogen were studied in the presence of the salts in a chemically defined medium at the same pH using a proteomic approach. The total numbers of protein spots obtained from two-dimensional electrophoresis were 198, 150, and 131 for sodium diacetate, sodium lactate, and the control, respectively. Sodium diacetate treatment produced the highest number of unmatched proteins (124 versus 53 in lactate), the greatest increase in expression (20 versus 5 in lactate), and the highest number of novel proteins (90 versus 45 in lactate). The number of repressed proteins was highest in the combination treatment (41 versus ∼30 in the single salt treatment). Six proteins that increased or decreased by ≥10-fold were further investigated; oxidoreductase and lipoprotein were upregulated, and DNA-binding protein, alpha amylase, and two SecA proteins were downregulated or completely suppressed by the salt treatment. Identification of all protein spots is essential for comparison with proteins induced or suppressed under other stress conditions.

Prevalence and Genetic Diversity of Listeria monocytogenes in Vacuum-Packaged Ready-to-Eat Meat Products at Retail Markets in Latvia

2009 ◽  
Vol 72 (6) ◽  
pp. 1283-1287 ◽  
Author(s):  
AIVARS BĒRZIŅŠ ◽  
MARGARITA TERENTJEVA ◽  
HANNU KORKEALA
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Meat Products ◽  
Processing Plant ◽  
Meat Processing ◽  
Pork Products ◽  
Beef Products ◽  
Processing Plants ◽  
Serotype 1 ◽  
Packaged Beef

Nine groups of different retail ready-to-eat vacuum-packaged meat products from 10 Baltic meat processing plants were analyzed for presence and numbers of Listeria monocytogenes at the end of shelf life. A total of 38 (18%) of 211 samples tested positive for L. monocytogenes serotype 1/2a (88%) or 1/2c (12%). The prevalence of L. monocytogenes in cold-smoked, sliced, vacuum-packaged beef and pork products (42%) was significantly higher than in cooked, sliced, vacuum-packaged meat products (0.8%) (P < 0.001). Enumeration of L. monocytogenes showed that 84% of the positive samples contained <100 CFU/g upon expiry of product shelf life. The numbers of L. monocytogenes exceeded 100 CFU/g only in cold-smoked, sliced, vacuum-packaged beef products. Identical pulsed-field gel electrophoresis types were recovered from different production lots of cold-smoked vacuum-packaged beef and pork products produced by the same meat processing plant, demonstrating L. monocytogenes contamination as a recurrent problem within one meat processing plant.

Modeling the Effect of Storage Atmosphere on Growth–No Growth Interface of Listeria monocytogenes as a Function of Temperature, Sodium Lactate, Sodium Diacetate, and NaCl

2007 ◽  
Vol 70 (10) ◽  
pp. 2329-2338 ◽  
Author(s):  
PANAGIOTIS N. SKANDAMIS ◽  
JARRET D. STOPFORTH ◽  
YOHAN YOON ◽  
PATRICIA A. KENDALL ◽  
JOHN N. SOFOS
Keyword(s):  
Listeria Monocytogenes ◽  
Growth Models ◽  
Meat Products ◽  
Optimal Growth ◽  
Sodium Lactate ◽  
Growth Responses ◽  
Growth Interface ◽  
Aerobic Conditions ◽  
Sodium Diacetate ◽  
Anaerobic Storage

The effect of aerobic and anaerobic conditions on growth initiation by a 10-strain composite of Listeria monocytogenes (104 CFU/ml) was evaluated in tryptic soy broth with 0.6% yeast extract (TSBYE) as a function of 220 combinations of pH (3.82 to 7.42), sodium lactate (SL) (0 to 10%, vol/vol), and sodium diacetate (SD) (0 to 0.5%, wt/vol) at 10 or 30°C (a slightly abusive and the optimal growth temperature, both above the growth limiting range of 0 to 3°C for L. monocytogenes) in 96-well microplates. In addition, four probability-of-growth models were developed to quantify the effect of 346 aerobic and 346 anaerobic combinations of temperature (4 to 30°C), SL (0 to 6%, vol/vol), and SD (0 to 0.5%, wt/vol) in the presence of NaCl (0.5 or 2.5%, wt/vol) on the growth–no growth responses of the same L. monocytogenes strain composite, with a microplate reader. Growth responses were evaluated turbidimetrically (620 nm) every 5 days for a total of 40 days. Data were modeled with logistic regression to determine the growth–no growth interfaces. The minimum pH values at which growth of L. monocytogenes occurred were higher under anaerobic than under aerobic conditions, and this difference was more evident at 10°C or at higher SL and SD concentrations. The MIC of SD decreased with increasing SL levels. Anaerobic storage reduced the levels of SL-SD, allowing the growth of L. monocytogenes compared with aerobic storage, especially at low temperatures. In the presence of 2.5% NaCl, the MICs for SD were lower than those obtained with 0.5% NaCl, especially at 4 and 10°C, or in the presence of 5 to 6% SL. The developed models for anaerobic incubation showed good performance (80% successful predictions; i.e., in 40 of 50 comparisons) with independent data from studies on survival-growth of L. monocytogenes on meat products. The study provides quantitative data on the antimicrobial activity of SL (0 to 10%) and SD (0 to 0.5%), temperature (4 to 30°C), and pH (3.82 to 7.42) and on the probability of growth of L. monocytogenes under anaerobic or aerobic conditions in the presence of 0.5 or 2.5% NaCl, and hence, addresses important needs for risk assessment activities.

Organic Acids and Their Salts as Dipping Solutions To Control Listeria monocytogenes Inoculated following Processing of Sliced Pork Bologna Stored at 4°C in Vacuum Packages

2001 ◽  
Vol 64 (11) ◽  
pp. 1722-1729 ◽  
Author(s):  
JOHN SAMELIS ◽  
JOHN N. SOFOS ◽  
MINDY L. KAIN ◽  
JOHN A. SCANGA ◽  
KEITH E. BELK ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Organic Acids ◽  
Safety Issue ◽  
Sodium Lactate ◽  
Commercial Application ◽  
Potassium Sorbate ◽  
Cured Meats ◽  
Potassium Benzoate ◽  
Sodium Diacetate

Postprocessing contamination of cured meats with Listeria monocytogenes has become a major concern for the meat processing industry and an important food safety issue. This study evaluated aqueous dipping solutions of organic acids (2.5 or 5% lactic or acetic acid) or salts (2.5 or 5% sodium acetate or sodium diacetate, 5 or 10% sodium lactate, 5% potassium sorbate or potassium benzoate) to control L. monocytogenes on sliced, vacuum-packaged bologna stored at 4°C for up to 120 days. Organic acids and salts were applied by immersing (1 min) in each solution inoculated (102 to 103 CFU/cm2) slices of bologna before vacuum packaging. Growth of L. monocytogenes (PALCAM agar) on inoculated bologna slices without treatment exceeded 7 log CFU/cm2 (P < 0.05) at 20 days of storage. No significant (P > 0.05) increase in L. monocytogenes populations occurred on bologna slices treated with 2.5 or 5% acetic acid, 5% sodium diacetate, or 5% potassium benzoate from day 0 to 120. Products treated with 5% potassium sorbate and 5% lactic acid were stored for 50 and 90 days, respectively, before a significant (P < 0.05) increase in L. monocytogenes occurred. All other treatments permitted growth of the pathogen at earlier days of storage, with sodium lactate (5 or 10%) permitting growth within 20 to 35 days. Extent of bacterial growth on trypticase soy agar plus 0.6% yeast extract (TSAYE) was similar to that on PALCAM, indicating that the major part of total bacteria grown on TSAYE agar plates incubated at 30°C was L. monocytogenes. Further studies are needed to evaluate organic acids and salts as dipping solutions at abusive temperatures of retail storage, to optimize their concentrations in terms of product sensory quality, and to evaluate their effects against various other types of microorganisms and on product shelf life. In addition, technologies for the commercial application of postprocessing antimicrobial solutions in meat plants need to be developed.

Modeling the Growth Boundary of Listeria monocytogenes in Ready-to-Eat Cooked Meat Products as a Function of the Product Salt, Moisture, Potassium Lactate, and Sodium Diacetate Concentrations

2004 ◽  
Vol 67 (10) ◽  
pp. 2195-2204 ◽  
Author(s):  
J. D. LEGAN ◽  
D. L. SEMAN ◽  
A. L. MILKOWSKI ◽  
J. A. HIRSCHEY ◽  
M. H. VANDEVEN
Keyword(s):  
Listeria Monocytogenes ◽  
Meat Products ◽  
Growth Conditions ◽  
Continuous Variables ◽  
Surface Design ◽  
Potassium Lactate ◽  
Contour Plots ◽  
Sodium Diacetate ◽  
Factor Interactions ◽  
Composite Response

A central composite response surface design was used to determine the time to growth of Listeria monocytogenes as a function of four continuous variables: added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.2%), potassium lactate syrup (60% [wt/wt]; 0.25 to 9.25%), and finished-product moisture (45.5 to 83.5%) in ready-to-eat cured meat products. The design was repeated for ready-to-eat uncured meat products giving a fifth categorical variable for cure status. Products were stored at 4°C. The results were modeled using a generalized regression approach. All five main effects, six two-factor interactions, and two quadratic terms were statistically significant. The model was used to show the boundary between growth and no-growth conditions at 4°C using contour plots of time to growth. It was validated using independent challenge studies of cured and uncured products. Generally, the model predicted well, particularly for cured products, where it will be useful for establishing conditions that prevent the growth of L. monocytogenes. For uncured products, there was good agreement overall between predicted and observed times to growth, but the model is less thoroughly validated than for cured products. The model should initially only be used for screening of formulations likely to prevent growth of Listeria monocytogenes in uncured products, with recommendations subject to confirmation by challenge studies.

Control of Listeria monocytogenes with Combined Antimicrobials after Postprocess Contamination and Extended Storage of Frankfurters at 4° C in Vacuum Packages

2002 ◽  
Vol 65 (2) ◽  
pp. 299-307 ◽  
Author(s):  
JOHN SAMELIS ◽  
GERARD K. BEDIE ◽  
JOHN N. SOFOS ◽  
KEITH E. BELK ◽  
JOHN A. SCANGA ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Acetate ◽  
Sensory Quality ◽  
Sodium Lactate ◽  
Hot Water ◽  
Processed Meat ◽  
C Storage ◽  
Heat Treated ◽  
Cured Meat ◽  
Sodium Diacetate

Contamination of ready-to-eat foods, such as frankfurters, with Listeria monocytogenes, is a major concern that needs to be addressed in order to enhance the safety of these products. The objective of this study was to determine the effectiveness of combinations of antimicrobials included in the formulation of frankfurters against L. monocytogenes inoculated (103 to 104 CFU/cm2) on their surface after peeling and before vacuum packaging. In addition, the antilisterial effect of immersing the packaged products, prepared with or without antimicrobials, in hot (75 or 80°C) water for 30 to 90 s was evaluated. Samples were stored at 4°C for up to 120 days and periodically analyzed for pH and for microbial growth on tryptic soy agar plus 0.6% yeast extract (TSAYE) and PALCAM agar. Sodium lactate (1.8%; 3% of a 60% commercial solution) used alone inhibited growth of L. monocytogenes for 35 to 50 days, whereas when used in combination with 0.25% sodium acetate, sodium diacetate, or glucono-δ-lactone (GDL), sodium lactate inhibited growth throughout storage (120 days). Immersing packaged frankfurters in hot water (80°C, 60 s) reduced inoculated populations of L. monocytogenes by 0.4 to 0.9 log CFU/cm2 and reduced its growth by 1.1 to 1.4 log CFU/cm2 at 50 to 70 days of storage in samples containing 1.8% sodium lactate alone. However, immersion of frankfurters containing no antimicrobials in hot water (75 or 80°C) did not inhibit growth of the pathogen for more than 10 to 20 days, unless one frankfurter was placed per bag and heat treated for 90 s. These results indicate that the inclusion of 1.8% sodium lactate with 0.25% sodium acetate, sodium diacetate, or GDL in cured meat formulations may control L. monocytogenes growth during refrigerated (4°C) storage. Additional studies are required to evaluate the effects of these combinations at abusive temperatures of storage, as well as on additional processed meat formulations and on the sensory quality and shelf life of products.

scholarly journals Occurrence of Listeria monocytogenes in Ready-to-Eat Meat Products and Meat Processing Plants in Spain

Foods ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 271-282 ◽  
Author(s):  
Diego Gómez ◽  
Laura Iguácel ◽  
Mª Rota ◽  
Juan Carramiñana ◽  
Agustín Ariño ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Meat Products ◽  
Meat Processing ◽  
Processing Plants

Use of UV Light for the Inactivation of Listeria monocytogenes and Lactic Acid Bacteria Species in Recirculated Chill Brines

2008 ◽  
Vol 71 (3) ◽  
pp. 629-633 ◽  
Author(s):  
K. M. GAILUNAS ◽  
K. E. MATAK ◽  
R. R. BOYER ◽  
C. Z. ALVARADO ◽  
R. C. WILLIAMS ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Thermal Processing ◽  
Uv Light ◽  
Light Exposure ◽  
Meat Products ◽  
Uv Treatment ◽  
Bacterial Populations ◽  
Log Reduction

Ready-to-eat meat products have been implicated in several foodborne listeriosis outbreaks. Microbial contamination of these products can occur after thermal processing when products are chilled in salt brines. The objective of this study was to evaluate UV radiation on the inactivation of Listeria monocytogenes and lactic acid bacteria in a model brine chiller system. Two concentrations of brine (7.9% [wt/wt] or 13.2% [wt/wt]) were inoculated with a ~6.0 log CFU/ml cocktail of L. monocytogenes or lactic acid bacteria and passed through a UV treatment system for 60 min. Three replications of each bacteria-and-brine combination were performed and resulted in at least a 4.5-log reduction in microbial numbers in all treated brines after exposure to UV light. Bacterial populations were significantly reduced after 5 min of exposure to UV light in the model brine chiller compared with the control, which received no UV light exposure (P < 0.05). The maximum rate of inactivation for both microorganisms in treated brines occurred between minutes 1 and 15 of UV exposure. Results indicate that in-line treatment of chill brines with UV light reduces the number of L. monocytogenes and lactic acid bacteria.

Postprocess Control of Listeria monocytogenes on Commercial Frankfurters Formulated with and without Antimicrobials and Stored at 10°C

2006 ◽  
Vol 69 (1) ◽  
pp. 53-61 ◽  
Author(s):  
IFIGENIA GEORNARAS ◽  
PANAGIOTIS N. SKANDAMIS ◽  
KEITH E. BELK ◽  
JOHN A. SCANGA ◽  
PATRICIA A. KENDALL ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Lag Phase ◽  
Potassium Lactate ◽  
Potassium Benzoate ◽  
Sodium Diacetate ◽  
Specific Growth Rates ◽  
Spoilage Microflora ◽  
Antimicrobial Treatments ◽  
Microbiological Analyses ◽  
Different Sources

The antilisterial effect of postprocess antimicrobial treatments on commercially manufactured frankfurters formulated with and without a 1.5% potassium lactate–0.05% sodium diacetate combination was evaluated. Frankfurters were inoculated (ca. 3 to 4 log CFU/cm2) with 10-strain composite Listeria monocytogenes cultures originating from different sources. The inocula evaluated were cells grown planktonically in tryptic soy broth plus 0.6% yeast extract (30°C, 24 h) or in a smoked sausage homogenate (15°C, 7 days) and cells that had been removed from stainless steel coupons immersed in an inoculated smoked sausage homogenate (15°C, 7 days). Inoculated frankfurters were dipped (2 min, 25 ± 2°C) in acetic acid (AA; 2.5%), lactic acid (LA; 2.5%), potassium benzoate (PB; 5%), or Nisaplin (commercial form of nisin; 0.5%, equivalent to 5,000 IU/ml of nisin) solutions, or in Nisaplin followed by AA, LA, or PB, and were subsequently vacuum packaged and stored for 48 days at 10°C. In addition to microbiological analyses, sensory evaluations were performed with uninoculated samples that had been treated with AA, LA, or PB for 2 min. Initial L. monocytogenes populations were reduced by 1.0 to 1.8 log CFU/cm2 following treatment with AA, LA, or PB solutions, and treatments that included Nisaplin reduced initial levels by 2.4 to >3.8 log CFU/cm2. All postprocessing treatments resulted in some inhibition of L. monocytogenes during the initial stages of storage of frankfurters that were not formulated with potassium lactate–sodium diacetate; however, in all cases, significant (P < 0.05) growth occurred by the end of storage. The dipping of products formulated with potassium lactate–sodium diacetate in AA or LA alone—or in Nisaplin followed by AA, LA, or PB—increased lag-phase durations and lowered the maximum specific growth rates of the pathogen. Moreover, depending on the origin of the inoculum, this dipping of products led to listericidal effects. In general, differences in growth kinetics were obtained for the three inocula that were used to contaminate the frankfurters. Possible reasons for these differences include the presence of stress-adapted subpopulations and the inhibition of the growth of the pathogen due to high levels of spoilage microflora. The dipping of frankfurters in AA, LA, or PB did not (P > 0.05) affect the sensory attributes of the product when compared to the control samples. The data generated in this study may be useful to U.S. ready-to-eat meat processors in their efforts to comply with regulatory requirements.

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