Survival of Campylobacter jejuni in Modified Atmosphere Packaged Turkey Roll

1991 ◽  
Vol 54 (3) ◽  
pp. 194-199 ◽  
Author(s):  
RANDALL K. PHEBUS ◽  
FRANCES A. DRAUGHON ◽  
JOHN R. MOUNT
Keyword(s):  
Lactic Acid ◽  
Campylobacter Jejuni ◽  
Co2 Concentration ◽  
Initial Population ◽  
Modified Atmosphere ◽  
Bacterial Populations ◽  
Direct Plating ◽  
Low Co2 ◽  
Co2 Levels ◽  
Storage Temperatures

Survival of Campylobacter jejuni, inoculated into turkey roll slices and stored under seven different atmospheric mixtures, was determined. Turkey roll samples were stored at 4°C for 18 d and at 21°C for 48 h. The effects of various atmospheric mixtures on aerobic, psychrotrophic, and lactic acid bacterial populations were also determined throughout storage. Campylobacter jejuni was inactivated under all atmospheric gas mixtures tested throughout storage. Increasing CO2 concentration inside the package from 0% to 100% CO2 resulted in a lower rate of inactivation of C. jejuni at both storage temperatures. Increases in CO2 concentrations provided greater inhibition of aerobic and psychrotrophic populations as compared to low CO2 levels. The effect of CO2 on survival of C. jejuni and growth rate of aerobic, psychrotrophic, and lactic acid bacteria was more pronounced at 4°C. Campylobacters were isolated from inoculated turkey roll held under all atmospheres by enrichment procedures on the 18th day and 48th hour of storage at 4 and 21°C, respectively, with an initial population of log 6.0 Campylobacter s/g. However, no Campylobacters were isolated by 18 d of storage at 4°C by direct plating.

Survival of lactic acid and chlorine dioxide treated Campylobacter jejuni under suboptimal conditions of pH, temperature and modified atmosphere

2010 ◽  
Vol 141 ◽  
pp. S140-S146 ◽  
Author(s):  
Nada Smigic ◽  
Andreja Rajkovic ◽  
Dennis Sandris Nielsen ◽  
Nils Arneborg ◽  
Henrik Siegumfeldt ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Campylobacter Jejuni ◽  
Chlorine Dioxide ◽  
Modified Atmosphere

scholarly journals Efficacy of Lactic Acid and Modified Atmosphere Packaging against Campylobacter jejuni on Chicken during Refrigerated Storage

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 109 ◽  
Author(s):  
Elena Gonzalez-Fandos ◽  
Naiara Maya ◽  
Alba Martínez-Laorden ◽  
Iratxe Perez-Arnedo
Keyword(s):  
Lactic Acid ◽  
Acid Solution ◽  
Campylobacter Jejuni ◽  
Modified Atmosphere Packaging ◽  
Modified Atmosphere ◽  
Distilled Water ◽  
Water Control ◽  
Lactic Acid Solution ◽  
Modified Atmospheres ◽  
Chicken Legs

The present study was conducted to evaluate the combined effect of lactic acid washing and modified atmospheres packaging on the counts of Campylobacter jejuni on chicken legs stored at 4 °C. In experiment 1, inoculated chicken legs were washed with either 1% or 2% lactic acid solution for 5 min or distilled water (control). The treatment with 2% lactic acid reduced C. jejuni counts 1.42 log units after treatment (day 0). In experiment 2, inoculated samples were packaged under different conditions: air, 100%N2, vacuum, 20%CO2/80%N2, or 40%CO2/60%N2. C. jejuni counts were higher in samples packaged under vacuum or atmospheres containing CO2 than in air. In experiment 3, inoculated chicken legs were washed with a 2% lactic acid solution for 5 min or distilled water (control). Samples were packaged under different conditions: air, vacuum, 20%CO2/80%N2, or 40%CO2/60%N2. C. jejuni counts were lower in samples treated with lactic acid than in samples non-treated. However, C. jejuni counts were higher in chicken legs treated with lactic acid and packaged in modified atmospheres than in those treated and packaged in air. Immersion of chicken legs in a solution containing 2% lactic acid can reduce C. jejuni counts on fresh chicken packaged in modified atmosphere.

Sensitivity and Resistance of Listeria monocytogenes ATCC 19115, Scott A, and UAL500 to Nisin

1991 ◽  
Vol 54 (11) ◽  
pp. 836-840 ◽  
Author(s):  
LINDA J. HARRIS ◽  
HENRY P. FLEMING ◽  
TODD R. KLAENHAMMER
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Food Systems ◽  
Initial Population ◽  
Medium Ph ◽  
Direct Plating ◽  
Plating Method

Listeria monocytogenes ATCC 19115, Scott A, and UAL500 were evaluated for sensitivity to nisin (0 to 50 μg/ml) using a direct plating method. Nisin (10 μg/ml) decreased an initial population of L. monocytogenes (109 CFU per ml) by 6- to 7-log cycles. Sensitivity to nisin was enhanced by addition of 2% NaCl or by reduction of the medium pH from 6.5 to 5.5 with either hydrochloric or lactic acid. Mutants resistant to 50 μg/ml nisin were detected at frequencies of 10−6 to 10−8. Nisin-resistant L. monocytogenes mutants should be expected to arise when nisin is used as an antimicrobial in food systems.

scholarly journals Modeling the Growth/No-Growth Boundaries of Postprocessing Listeria monocytogenes Contamination on Frankfurters and Bologna Treated with Lactic Acid

2008 ◽  
Vol 75 (2) ◽  
pp. 353-358 ◽  
Author(s):  
Yohan Yoon ◽  
Patricia A. Kendall ◽  
Keith E. Belk ◽  
John A. Scanga ◽  
Gary C. Smith ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Model Performance ◽  
Bacterial Populations ◽  
Response Data ◽  
Acceptable Model ◽  
And Storage ◽  
Storage Temperatures ◽  
Dipping Time

ABSTRACT This study developed models to predict lactic acid concentration, dipping time, and storage temperature combinations determining growth/no-growth interfaces of Listeria monocytogenes at desired probabilities on bologna and frankfurters. L. monocytogenes was inoculated on bologna and frankfurters, and 75 combinations of lactic acid concentrations, dipping times, and storage temperatures were tested. Samples were stored in vacuum packages for up to 60 days, and bacterial populations were enumerated on tryptic soy agar plus 0.6% yeast extract and Palcam agar on day zero and at the end point of storage. The combinations that allowed L. monocytogenes increases of ≥1 log CFU/cm2 were assigned the value of 1 (growth), and the combinations that had increases of <l log CFU/cm2 were given the value of 0 (no growth). These binary growth response data were fitted to logistic regression to develop a model predicting probabilities of growth. Validation with existing data and various indices showed acceptable model performance. Thus, the models developed in this study may be useful in determining probabilities of growth and in selecting lactic acid concentrations and dipping times to control L. monocytogenes growth on bologna and frankfurters, while the procedures followed may also be used to develop models for other products, conditions, or pathogens.

Changes in Microbial Parameters and Gas Composition During Modified Atmosphere Storage of Fresh Pork Loin Cuts

1991 ◽  
Vol 54 (10) ◽  
pp. 778-783 ◽  
Author(s):  
LYNN M. MCMULLEN ◽  
MICHAEL E. STILES
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Storage Life ◽  
Microbial Load ◽  
Modified Atmosphere ◽  
Packaging Film ◽  
Brochothrix Thermosphacta ◽  
Pork Loin ◽  
Atmosphere Storage ◽  
Storage Temperatures

The storage life of modified atmosphere packaged pork loin cuts in 40% CO2 and 60% N2 was determined at −1, 4.4, and 10°C in three packaging films with oxygen transmission rates (OTR) of 0.0, 12.6, and 26.5 ml/m2/24 h at 23°C, 0% relative humidity and 1 atm pressure. The pork loin cuts were “commercially” or “aseptically” prepared. Gas atmosphere of the packages, microbial load, and pH were monitored throughout storage. The principal factor influencing change in the headspace gases under the conditions of these studies was gas transmission through the packaging film. A 100-fold difference in initial microbial load between commercially and aseptically prepared meat cuts resulted in a 2-week difference in storage life at both −1 and 4.4°C. Spoilage at each of the three storage temperatures could be attributed to the growth of different groups of bacteria and was influenced by package type. At −1°C, Brochothrix thermosphacta was the predominating microflora of samples stored in plastic film with an OTR of 26.5; lactic acid bacteria predominated on samples stored in foil packs with 0.0 and 12.6 OTR. At 4.4°C, lactic acid bacteria predominated, and at 10°C, Enterobacteriaceae predominated, regardless of packaging film. Under commercial packaging conditions in foil laminate packages with 0.0 or 12.6 OTR, storage life of pork cuts was 5 or 8 weeks at 4.4 or −1°C, respectively. This result was not definitive because of a difference among replicates. Samples in replicate 2 had a reduced storage life at each of the three storage temperatures.

scholarly journals Stochasticity in Colonial Growth Dynamics of Individual Bacterial Cells

2013 ◽  
Vol 79 (7) ◽  
pp. 2294-2301 ◽  
Author(s):  
Konstantinos P. Koutsoumanis ◽  
Alexandra Lianou
Keyword(s):  
Kinetic Parameters ◽  
Single Cells ◽  
Growth Curves ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Initial Population ◽  
Bacterial Cells ◽  
Stochastic Growth ◽  
Bacterial Populations ◽  
Content Type

ABSTRACTConventional bacterial growth studies rely on large bacterial populations without considering the individual cells. Individual cells, however, can exhibit marked behavioral heterogeneity. Here, we present experimental observations on the colonial growth of 220 individual cells ofSalmonella entericaserotype Typhimurium using time-lapse microscopy videos. We found a highly heterogeneous behavior. Some cells did not grow, showing filamentation or lysis before division. Cells that were able to grow and form microcolonies showed highly diverse growth dynamics. The quality of the videos allowed for counting the cells over time and estimating the kinetic parameters lag time (λ) and maximum specific growth rate (μmax) for each microcolony originating from a single cell. To interpret the observations, the variability of the kinetic parameters was characterized using appropriate probability distributions and introduced to a stochastic model that allows for taking into account heterogeneity using Monte Carlo simulation. The model provides stochastic growth curves demonstrating that growth of single cells or small microbial populations is a pool of events each one of which has its own probability to occur. Simulations of the model illustrated how the apparent variability in population growth gradually decreases with increasing initial population size (N0). For bacterial populations withN0of >100 cells, the variability is almost eliminated and the system seems to behave deterministically, even though the underlying law is stochastic. We also used the model to demonstrate the effect of the presence and extent of a nongrowing population fraction on the stochastic growth of bacterial populations.

scholarly journals Role of Broiler Carcasses and Processing Plant Air in Contamination of Modified-Atmosphere-Packaged Broiler Products with Psychrotrophic Lactic Acid Bacteria

2006 ◽  
Vol 73 (4) ◽  
pp. 1136-1145 ◽  
Author(s):  
Elina Vihavainen ◽  
Hanna-Saara Lundstr�m ◽  
Tuija Susiluoto ◽  
Joanna Koort ◽  
Lars Paulin ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Processing Plant ◽  
Modified Atmosphere ◽  
Production Plant ◽  
Meat Spoilage

ABSTRACT Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmosphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of HindIII restriction fragment length polymorphism (RFLP) patterns of the 16 and 23S rRNA genes as operational taxonomic units in numerical analyses. Six hundred thirteen LAB isolates from the total of 655 clustered in 29 groups considered to be species specific. Sixty-four percent of product isolates clustered either with Carnobacterium divergens or with Carnobacterium maltaromaticum type strains. The third major product-associated cluster (17% of isolates) was formed by unknown LAB. Representative strains from these three clusters were analyzed for the phylogeny of their 16S rRNA genes. This analysis verified that the two largest RFLP clusters consisted of carnobacteria and showed that the unknown LAB group consisted of Lactococcus spp. No product-associated LAB were detected in broiler carcasses sampled at the beginning of slaughter, whereas carnobacteria and lactococci, along with some other specific meat spoilage LAB, were recovered from processing plant air at many sites. This study reveals that incoming broiler chickens are not major sources of psychrotrophic spoilage LAB, whereas the detection of these organisms from the air of the processing environment highlights the role of processing facilities as sources of LAB contamination.

scholarly journals A Clean-In-Place Type Sanitation Method Validation for a Benchtop Meat Grinder

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
C. E. Rayfield ◽  
R. Jadeja ◽  
S. Billups
Keyword(s):  
Lactic Acid ◽  
Foodborne Pathogens ◽  
Peracetic Acid ◽  
Deionized Water ◽  
Cross Contamination ◽  
Direct Plating ◽  
Water Ice ◽  
E Coli ◽  
Different Types ◽  
Low Levels

ObjectivesThis research is designed to validate a novel clean-in-place type antimicrobial ice-based meat grinder sanitation method.Materials and MethodsFour different types of antimicrobial ice were prepared from peracetic acid (PAA, 350 mg/L) and combination PAA with 2% FreshFX® (PAAF), 2% Paradigm® (PAAP) and 2% lactic acid (PAAL). The grinders were inoculated by processing 400 g beef trim containing 400 μL of E. coli O157:H7 or S. Typhimurium DT 104 suspensions at 8.4 to 8.7 (high inoculation) and 5.3 to 5.5 (low inoculation) log CFU/mL. Each meat grinder was then treated by processing 1000 g of antimicrobial ice and 500 mL of corresponding antimicrobial solution. At the end of each treatment, 400 g un-inoculated beef was processed through the meat grinder, and the resulting ground beef was then analyzed for the presence of target pathogens by direct plating and after enrichment. Efficacies of antimicrobial ice-based treatments were compared with 1000 g deionized water ice + 500 mL deionized water (DI), and no treatment (NT) controls.ResultsAll antimicrobial ice treatments were able to reduce cross-contamination to non-detectable levels from the meat grinders inoculated at the low levels of pathogens, but after enrichment, target pathogens were detected in all the samples. Recoveries from the meat grinder inoculated with high levels of pathogens ranged from 5.95 to 3.50 log CFU/g and 5.86 to 3.46 log CFU/g for E. coli O157:H7 and S. Typhimurium DT 104, respectively. All antimicrobial ice treatments were significantly (p ≤ 0.05) more effective in reducing cross-contamination in comparison of NT and DI controls. The microbial reductions achieved by different antimicrobial ice treatments were not significantly (p ≤ 0.05) different from each other.ConclusionThe antimicrobial ice-based meat grinder sanitation technique could effectively reduce foodborne pathogens from meat grinders without needing meat grinder disassembly.

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