Behavior of Listeria monocytogenes in the Presence of Sodium Propionate Together with Food Acids

1992 ◽  
Vol 55 (4) ◽  
pp. 241-245 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Tartaric Acid ◽  
Lag Phase ◽  
Sodium Propionate ◽  
Acid Growth ◽  
Slight Growth

Tryptose broth (TB) containing 0.00, 0.05, 0.15, or 0.3% sodium propionate was adjusted to pH 5.0 or 5.6 with acetic, tartaric, lactic, or citric acid, inoculated to contain ca. 103 CFU of Listeria monocytogenes/ml and incubated at 13 or 35°C. The bacterium grew in all controls (free of propionate) under all conditions; however, only slight growth occurred at 13°C when the pH was adjusted to 5.0 with acetic or tartaric acid. Growth also occurred at 13 and 35°C when TB adjusted to pH 5.6 with acetic or tartaric acid contained 0.05 or 0.15% propionate, but 0.3% inhibited growth of the pathogen. When the pH of TB was adjusted to 5.0 with the same acids, L. monocytogenes was inhibited or inactivated by 0.15 or 0.3% propionate. The pathogen grew at 13 or 35°C in TB that contained 0.05 or 0.15% propionate and was adjusted to pH 5.6 with lactic or citric acid although the lag phase was prolonged as the concentration of propionate was increased. Under these conditions, propionate at 0.3% occasionally inhibited growth of L. monocytogenes. Growth was reduced and sometimes inhibited completely by 0.15 or 0.3% propionate when the pH of TB was adjusted to 5.0 with the same acids.

Inhibition or Inactivation of Listeria monocytogenes by Sodium Benzoate together with some Organic Acids

1989 ◽  
Vol 52 (11) ◽  
pp. 771-776 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Organic Acids ◽  
Tartaric Acid ◽  
Sodium Benzoate ◽  
Test Conditions ◽  
Slight Growth

Tests were done to determine the fate of Listeria monocytogenes at 13 or 35°C in Tryptose Broth (TB) with and without the pH adjusted to 5.6 or 5.0 using acetic, tartaric, lactic, or citric acid and containing 0.00, 0.05, 0.15, or 0.3% sodium benzoate. The bacterium grew in all controls (free of benzoate) under all conditions except only slight growth was detected at 13°C when the pH was adjusted to 5.0 using acetic or tartaric acid. When TB was acidified with acetic or tartaric acid and incubated at 35°C, the bacterium was inactivated or inhibited under all conditions except growth occurred at pH 5.6 with 0.05 or 0.15% sodium benzoate and at pH 5.0 with 0.05% benzoate. Incubation at 13°C with the same acids in TB was accompanied by inactivation or inhibition of the bacterium at all test conditions except in the presence of 0.05% sodium benzoate and pH 5.6 obtained by added acetic acid, and in the presence of 0.05 or 0.15% benzoate when tartaric acid was used to adjust the pH to 5.6. Acidifying TB with lactic or citric acid and incubating at 35°C resulted in growth at pH 5.0 and 5.6 regardless of concentration of benzoate except 0.3% which caused inhibition or inactivation at pH 5.6 or 5.0, respectively. Incubation at 13°C with the same acids in TB resulted in inactivation or inhibition of L. monocytogenes, except growth occurred at pH 5.6 when the medium contained 0.05 or 0.15% benzoate. Slight growth was observed in the presence of 0.05% benzoate at pH 5.0 when the medium was acidified by lactic or acetic acid.

Organic Acids Enhance the Antilisterial Activity of Potassium Sorbate

1991 ◽  
Vol 54 (8) ◽  
pp. 593-597 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Tartaric Acid ◽  
Incubation Temperature ◽  
Potassium Sorbate ◽  
Acid Growth ◽  
Time Required

Tryptose broth containing 0.0, 0.05, 0.15, or 0.3% potassium sorbate was acidified to pH 5.0 or 5.6 with acetic, tartaric, lactic or citric acid; inoculated to contain ca. 103 CFU Listeria monocytogenes/ml; and incubated at 13 or 35°C. The pathogen was inactivated in tryptose broth containing (a) 0.3% sorbate and acidified to pH 5.0 with acetic, tartaric, lactic, or citric acid although the time required for inactivation varied from ca. 30 h to > 10 d and (b) 0.15% sorbate and acidified to pH 5.0 with tartaric acid. Growth of the pathogen was inhibited to various degrees by other combinations of sorbate and organic acids. L. monocytogenes grew at pH 5.6 regardless of organic acid or incubation temperature used and at pH 5.0 in all instances except when acetic acid and incubation at 13°C were used.

The Combination of Lactate and Diacetate Synergistically Reduces Cold Growth in Brain Heart Infusion Broth across Listeria monocytogenes Lineages

2010 ◽  
Vol 73 (4) ◽  
pp. 631-640 ◽  
Author(s):  
MATTHEW J. STASIEWICZ ◽  
MARTIN WIEDMANN ◽  
TERESA M. BERGHOLZ
Keyword(s):  
Listeria Monocytogenes ◽  
Synergistic Effects ◽  
Brain Heart Infusion ◽  
Growth Parameter ◽  
Lag Phase ◽  
Minor Effect ◽  
Growth Inhibitors ◽  
Acid Growth ◽  
Potassium Lactate ◽  
Sodium Diacetate

Combinations of organic acids are often used in ready-to-eat foods to control the growth of Listeria monocytogenes during refrigerated storage. The purpose of this study was to quantitatively assess synergy between two organic acid growth inhibitors under conditions similar to those present in cold-smoked salmon, and to assess the effect of evolutionary lineage on response to those growth inhibitors. Thirteen strains of L. monocytogenes, representing lineages I and II, were grown at 7°C in broth at pH 6.1 and 4.65% water-phase NaCl, which was supplemented with 2% potassium lactate, 0.14% sodium diacetate, or the combination of both at the same levels. Our data suggest that lineages adapt similarly to these inhibitors, as the only significant growth parameter difference between lineages was a minor effect (± 0.16 day, P = 0.0499) on lag phase (λ). For all strains, lactate significantly extended λ, from 2.6 ± 0.4 to 3.8 ± 0.5 days (P < 0.001), and lowered the maximum growth rate (μmax) from 0.54 ± 0.06 to 0.49 ± 0.04 log(CFU/ml)/day (P < 0.001), compared with the control. Diacetate was ineffective alone, but in combination with lactate, synergistically increased λ to 6.6 ± 1.6 days (P < 0.001) and decreased μmax to 0.34 ± 0.05 log(CFU/ml)/day (P < 0.001). Monte Carlo simulations provided further evidence for synergy between diacetate and lactate by predicting signficantly slower growth to nominal endpoints for the combination of inhibitors. This study shows potassium lactate and sodium diacetate have significant synergistic effects on both λ and μmax of L. monocytogenes at refrigeration temperature in broth, and justifies combining these inhibitors, at effective levels, in food product formulations.

Growth of Listeria monocytogenes in a Model High-Moisture Cheese on the Basis of pH, Moisture, and Acid Type

2020 ◽  
Vol 83 (8) ◽  
pp. 1335-1344
Author(s):  
SARAH K. ENGSTROM ◽  
CHRISTIE CHENG ◽  
DENNIS SEMAN ◽  
KATHLEEN A. GLASS
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Ph Value ◽  
Growth Parameters ◽  
Growth Curves ◽  
Lag Phase ◽  
High Moisture ◽  
Contrast Model ◽  
Acid Type

ABSTRACT High-moisture, low-acid cheeses have been shown to support Listeria monocytogenes growth during refrigerated storage. Prior studies suggest that organic acids vary in their antilisterial activity and that cheeses of lower pH delay growth longer than those of higher pH; however, no standard pH value for Listeria control in cheese exists. The objective of this research was to create a predictive model to include the effects of acid type, pH, and moisture on the growth of L. monocytogenes in a model cheese system. Cream, micellar casein, water, lactose, salt, and acid (citric, lactic, acetic, or propionic) were combined in 32 formulations targeting 4 pH values (5.25, 5.50, 5.75, and 6.00) and two moisture levels (50 and 56%). Each was inoculated with 3 log CFU/g L. monocytogenes (five-strain mixture) after which 25-g samples were vacuum sealed and stored 8 weeks at 4°C. Triplicate samples were enumerated on modified Oxford agar weekly in duplicate trials. Model cheeses formulated with acetic and propionic acids inhibited growth (i.e., no observed increase in L. monocytogenes populations over 8 weeks) at pH ≤5.75, while those formulated with lactic acid inhibited growth at pH 5.25 only. In contrast, all model cheeses formulated with citric acid supported growth. Resulting growth curves were fitted for lag phase and growth rate before constructing models for each. The pH and acid type were found to significantly affect both growth parameters (P < 0.05), while moisture (50 to 56%) was not statistically significant in either model (P ≥ 0.05). The effects of acetic and propionic acid were not significantly different. In contrast, model cheeses made with citric acid had significantly shorter lag phases than the other acids tested, but growth rates after lag were statistically similar to model cheeses made with lactic acid. These data suggest propionic ∼ acetic > lactic > citric acids in antilisterial activity within the model cheese system developed and can be used in formulating safe high-moisture cheeses. HIGHLIGHTS

Effect of pH, Acidulant, Time, and Temperature on the Growth and Survival of Listeria monocytogenes

1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Malic Acid ◽  
Incubation Temperature ◽  
Growth And Survival ◽  
Ph Values

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).

Sodium Benzoate Inhibits Growth of or Inactivates Listeria monocytogenes

1988 ◽  
Vol 51 (7) ◽  
pp. 525-530 ◽  
Author(s):  
MOUSTAFA A. EL-SHENAWY ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Incubation Period ◽  
Sodium Benzoate ◽  
The Other ◽  
Complete Inhibition ◽  
Initial Population ◽  
Limited Growth ◽  
Complete Inactivation ◽  
Low Concentrations ◽  
Slight Growth

The ability of Listeria monocytogenes to grow or survive was determined using tryptose broth at pH 5.6 or 5.0, supplemented with 0, 0.05. 0.1, 0.15. 0.2. 0.25 or 0.3% sodium benzoate, and incubated at 4,13,21 or 35°C. The bacterium grew in benzoate-free controls under all conditions except at 4°C and pH 5.0. At pH 5.6 and 4°C, after 60 d, L. monocytogenes (initial population ca. 103/ml) was inactivated by 0.2, 0.25 and 0.3% sodium benzoate. Other concentrations of benzoate permitted slight growth during the first 36 d of incubation followed by a decrease in populations of the pathogen. At pH 5.0 and 4°C, from 0.15 to 0.3% benzoate completely inactivated the pathogen in 24 to 30 d, whereas the other concentrations caused a gradual decrease in the population during the 66-d incubation period. At 13°C and pH 5.6, L. monocytogenes grew (more at lower than higher concentrations of benzoate) in the presence of all concentrations of benzoate except 0.25 or 0.3%, which prohibited growth throughout a 264-h incubation period. Reducing the pH to 5.0 minimized growth at the two low concentrations of benzoate and caused slight decreases in population at the other concentrations of benzoate. At 21 and 35°C and pH 5.6, appreciable growth of L. monocytogenes occurred in the presence of 0.2% or less sodium benzoate, whereas higher concentrations were inhibitory, permitting little if any growth by the pathogen. Reducing the pH to 5.0 allowed limited growth of the pathogen at 21 and 35°C when the medium contained 0.05 or 0.1% sodium benzoate. Higher concentrations caused either complete inhibition or inhibition plus partial or complete inactivation of the pathogen during incubations of 117 h at 21°C or 78 h at 35°C.

scholarly journals Growth of Listeria monocytogenes in Thawed Frozen Foods

2017 ◽  
Vol 80 (3) ◽  
pp. 447-453 ◽  
Author(s):  
Ai Kataoka ◽  
Hua Wang ◽  
Philip H. Elliott ◽  
Richard C. Whiting ◽  
Melinda M. Hayman
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Growth Rates ◽  
Storage Temperature ◽  
Growth Parameters ◽  
Quadratic Model ◽  
Lag Phase ◽  
Frozen Foods ◽  
Phase Duration ◽  
Primary Model

ABSTRACT The growth characteristics of Listeria monocytogenes inoculated onto frozen foods (corn, green peas, crabmeat, and shrimp) and thawed by being stored at 4, 8, 12, and 20°C were investigated. The growth parameters, lag-phase duration (LPD) and exponential growth rate (EGR), were determined by using a two-phase linear growth model as a primary model and a square root model for EGR and a quadratic model for LPD as secondary models, based on the growth data. The EGR model predictions were compared with growth rates obtained from the USDA Pathogen Modeling Program, calculated with similar pH, salt percentage, and NaNO2 parameters, at all storage temperatures. The results showed that L. monocytogenes grew well in all food types, with the growth rate increasing with storage temperature. Predicted EGRs for all food types demonstrated the significance of storage temperature and similar growth rates among four food types. The predicted EGRs showed slightly slower rate compared with the values from the U.S. Department of Agriculture Pathogen Modeling Program. LPD could not be accurately predicted, possibly because there were not enough sampling points. These data established by using real food samples demonstrated that L. monocytogenes can initiate growth without a prolonged lag phase even at refrigeration temperature (4°C), and the predictive models derived from this study can be useful for developing proper handling guidelines for thawed frozen foods during production and storage.

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