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.

scholarly journals Efficacy of Cetylpyridinium Chloride against Listeria monocytogenes and Its Influence on Color and Texture of Cooked Roast Beef†

2005 ◽  
Vol 68 (11) ◽  
pp. 2349-2355 ◽  
Author(s):  
M. SINGH ◽  
H. THIPPAREDDI ◽  
R. K. PHEBUS ◽  
J. L. MARSDEN ◽  
T. J. HERALD ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Cetylpyridinium Chloride ◽  
Meat Products ◽  
Plate Count ◽  
Bacterial Populations ◽  
Plate Counts ◽  
Roast Beef ◽  
Aerobic Plate Count

Sliced (cut) and exterior (intact) surfaces of restructured cooked roast beef were inoculated with Listeria monocytogenes, treated with cetylpyridinium chloride (CPC; immersion in 500 ml of 1% solution for 1 min), individually vacuum packaged, and stored for 42 days at 0 or 4°C. Noninoculated samples were similarly treated, packaged, and stored to determine effects on quality (color and firmness) and on naturally occurring bacterial populations, including aerobic plate counts and lactic acid bacteria. Immediately after CPC treatment, regardless of inoculation level, L. monocytogenes populations were reduced (P = 0.05) by about 2 log CFU/cm2 on sliced surfaces and by about 4 log CFU/cm2 on exterior surfaces. Throughout 42 days of refrigerated storage (at both 0 and 4°C), L. monocytogenes populations on CPC-treated samples remained lower (P = 0.05) than those of nontreated samples for both surface types. After 42 days of storage at both 0 and 4°C, aerobic plate count and lactic acid bacteria populations of treated samples were 1 to 1.5 log CFU/cm2 lower (P = 0.05) than those of nontreated samples for both surface types. CPC treatment resulted in negligible effects (P > 0.05) on the color (L*, a*, and b* values) of exterior and sliced roast beef surfaces during storage. For both sliced and exterior surfaces, CPC-treated samples were generally less firm than nontreated samples. CPC treatment effectively reduced L. monocytogenes populations on roast beef surfaces and resulted in relatively minor impacts on color and texture attributes. CPC treatment, especially when applied to products prior to slicing, may serve as an effective antimicrobial intervention for ready-to-eat meat products.

Microbial Safety and Quality Evaluation of UV-Treated, Cold-Pressed Colored and Turbid Juices and Beverages

2018 ◽  
Vol 81 (9) ◽  
pp. 1549-1556 ◽  
Author(s):  
JESSIE USAGA ◽  
RANDY W. WOROBO
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Uv Light ◽  
Processing Unit ◽  
Fruit And Vegetable ◽  
Processing Technologies ◽  
Constant Flow Rate ◽  
Log Reduction ◽  
Nonthermal Processing ◽  
Cold Pressed

ABSTRACT The growing demand for fruit and vegetable juice blends, with improved nutritional and sensory attributes, has prompted the industrial adoption of nonthermal processing technologies, including UV light. Limited studies have explored conditions to overcome the well-known limitations of UV when treating liquid foods with a high content of particles that absorb or scatter UV light. This study addressed the effectiveness of the application of UV light, using a commercial processing unit, to inactivate pathogenic Escherichia coli O157:H7, Salmonella enterica (hereafter Salmonella), and Listeria monocytogenes, as well as spoilage microorganisms, in colored and turbid juices and beverages. The inactivation of cocktails of five strains (or serotypes) of E. coli O157:H7, Salmonella, and L. monocytogenes isolated from fruit- and vegetable-derived products linked to outbreaks was determined in seven colored and turbid cold-pressed juices and beverages. Juices and beverages were UV treated at a constant flow rate of 150 L/h through multiple consecutive passes. The inactivation of aerobic mesophilic bacteria, molds and yeasts, and lactic acid bacteria was also assessed at the cumulative dose that guaranteed a 5-log reduction of the most UV-tolerant pathogen for each product. A 5-log reduction of the three pathogens was achieved in all juices and beverages at a maximum cumulative UV dose of 12.0 ± 0.6 mJ/cm2. The dose required to ensure the targeted reduction varied depending on the tested product and the inoculated pathogen. The reduction of aerobic mesophiles, molds and yeasts, and lactic acid bacteria varied from 0.5 to 3.6, from 0.2 to 2.0, and from 0.5 to 3.6 log CFU/mL, respectively. Thus, the proposed treatment represents a suitable processing alternative to ensure the safety and extend the shelf life of colored and turbid cold-pressed juices and beverages.

Competitive Inhibition of Listeria monocytogenes in Ready-to-Eat Meat Products by Lactic Acid Bacteria†

2002 ◽  
Vol 65 (2) ◽  
pp. 316-325 ◽  
Author(s):  
A. AMÉZQUITA ◽  
M. M. BRASHEARS
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Competitive Inhibition ◽  
Meat Products ◽  
16S Rdna Sequence Analysis ◽  
Bacteriocin Producer ◽  
Cooked Ham ◽  
Significant Difference

Forty-nine strains of lactic acid bacteria (LAB), isolated from commercially available ready-to-eat (RTE) meat products, were screened for their ability to inhibit the growth of Listeria monocytogenes at refrigeration (5°C) temperatures on agar spot tests. The three most inhibitory strains were identified as Pediococcus acidilactici, Lactobacillus casei, and Lactobacillus paracasei by 16S rDNA sequence analysis. Their antilisterial activity was quantified in associative cultures in deMan Rogosa Sharpe (MRS) broth at 5°C for 28 days, resulting in a pathogen reduction of 3.5 log10 cycles compared to its initial level. A combined culture of these strains was added to frankfurters and cooked ham coinoculated with L. monocytogenes, vacuum packaged, and stored at 5°C for 28 days. Bacteriostatic activity was observed in cooked ham, whereas bactericidal activity was observed in frankfurters. Numbers of L. monocytogenes were 4.2 to 4.7 log10 and 2.6 log10 cycles lower than controls in frankfurters and cooked ham, respectively, after the 28-day refrigerated storage. In all cases, numbers of LAB increased by only 1 log10 cycle. The strain identified as P. acidilactici was possibly a bacteriocin producer, whereas the antilisterial activity of the other two strains was due to the production of organic acids. There was no significant difference (P > 0.05) in the antilisterial activity detected in frankfurters whether the LAB strains were used individually or as combined cultures. Further studies over a 56-day period indicated no impact on the quality of the product. This method represents a potential antilisterial intervention in RTE meats, because it inhibited the growth of the pathogen at refrigeration temperatures without causing sensory changes.

Effect of Age of Cook-in-Bag Delicatessen Meats Formulated with Lactate-Diacetate on the Behavior of Listeria monocytogenes Contamination Introduced When Opening the Packages during Storage

2013 ◽  
Vol 76 (7) ◽  
pp. 1274-1278 ◽  
Author(s):  
IFIGENIA GEORNARAS ◽  
DARREN TOCZKO ◽  
JOHN N. SOFOS
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Meat Products ◽  
Potential Effect ◽  
Meat Industry ◽  
Storage Product ◽  
Potassium Lactate ◽  
Yeasts And Molds ◽  
Effect Of Age

This study evaluated the potential effect of age of cook-in-bag ham and turkey breast delicatessen meats formulated with lactate-diacetate on survival and/or growth of Listeria monocytogenes introduced after opening of packages and slicing of product. Commercially prepared cured ham and turkey breast products formulated with potassium lactate and sodium diacetate were stored at 1.7°C unsliced, in their original cook-in-bags, and without postlethality exposure. On days 5, 90, 120, and 180 of storage, product slices (10.2 by 7.6 cm) were surface inoculated (1 to 2 log CFU/cm2) with a 10-strain mixture of L. monocytogenes, vacuum packaged (seven slices per bag), and stored at 4°C for up to 13 weeks. Inoculated levels of L. monocytogenes on both products were 1.4 to 1.5 log CFU/cm2. Irrespective of product age at slicing and inoculation, after 13 weeks of vacuum-packaged storage (4°C), pathogen counts on product slices were 1.5 to 2.3 (ham) and 2.3 to 2.5 (turkey) log CFU/cm2. Overall, the results of the study showed that the age of the cook-in-bag products prior to slicing and inoculation with the pathogen did not (P ≥ 0.05) affect the behavior of L. monocytogenes during vacuum-packaged storage (4°C, up to 13 weeks) of ham and turkey slices. Mean counts of lactic acid bacteria and yeasts and molds, when detected, did not exceed approximately 1 and 2 log CFU/cm2, respectively, among all stored samples. Findings of the study will be useful to the meat industry and risk assessors in their efforts to control L. monocytogenes in ready-to-eat meat products.

Quantifying Nonthermal Inactivation of Listeria monocytogenes in European Fermented Sausages Using Bacteriocinogenic Lactic Acid Bacteria or Their Bacteriocins: A Case Study for Risk Assessment

2006 ◽  
Vol 69 (11) ◽  
pp. 2648-2663 ◽  
Author(s):  
ELEFTHERIOS H. DROSINOS ◽  
MARIOS MATARAGAS ◽  
SLAVICA VESKOVIĆ-MORAČANIN ◽  
JUDIT GASPARIK-REICHARDT ◽  
MIRZA HADŽIOSMANOVIĆ ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Storage Temperature ◽  
Inactivation Kinetics ◽  
Initial Population ◽  
Log Reduction ◽  
Fermented Sausages

Listeria monocytogenes NCTC10527 was examined with respect to its nonthermal inactivation kinetics in fermented sausages from four European countries: Serbia-Montenegro, Hungary, Croatia, and Bosnia-Herzegovina. The goal was to quantify the effect of fermentation and ripening conditions on L. monocytogenes with the simultaneous presence or absence of bacteriocin-producing lactic acid bacteria (i.e., Lactobacillus sakei). Different models were used to fit the experimental data and to calculate the kinetic parameters. The best model was chosen based on statistical comparisons. The Baranyi model was selected because it fitted the data better in most (73%) of the cases. The results from the challenge experiments and the subsequent statistical analysis indicated that relative to the control condition the addition of L. sakei strains reduced the time required for a 4-log reduction of L. monocytogenes (t4D). In contrast, the addition of the bacteriocins mesenterocin Y and sakacin P decreased the t4D values for only the Serbian product. A case study for risk assessment also was conducted. The data of initial population and t4D collected from all countries were described by a single distribution function. Storage temperature, packaging method, pH, and water activity of the final products were used to calculate the inactivation of L. monocytogenes that might occur during storage of the final product (U.S. Department of Agriculture Pathogen Modeling Program version 7.0). Simulation results indicated that the addition of L. sakei strains significantly decreased the simulated L. monocytogenes concentration of ready-to-eat fermented sausages at the time of consumption.

scholarly journals Behavior of Listeria monocytogenes and Other Microorganisms in Sliced Riojano Chorizo (Spanish Dry-Cured Sausage) during Storage under Modified Atmospheres

2021 ◽  
Vol 9 (7) ◽  
pp. 1384
Author(s):  
Elena Gonzalez-Fandos ◽  
Maria Vazquez de Vazquez de Castro ◽  
Alba Martinez-Laorden ◽  
Iratxe Perez-Arnedo
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Potential Risk ◽  
Meat Product ◽  
Meat Products ◽  
Modified Atmosphere ◽  
Microbial Counts ◽  
Modified Atmospheres ◽  
Contamination Levels

Sliced ready-to-eat meat products packaged under modified atmospheres are often marketed since they cover consumer demands. The slicing process could be a potential risk for consumers since contamination with Listeria monocytogenes could occur during this stage. The current study evaluated the behavior of L. monocytogenes and other microorganisms in commercial sliced Riojano chorizo. This meat product was sliced and inoculated with L. monocytogenes (3.5 log CFU/g) before packaging under different atmospheres (air, vacuum, 100% N2, 20% CO2/80% N2 and 40% CO2/60% N2) and stored at 4 °C for up to 60 days. Samples were taken on days 0, 7, 21, 28 and 60 of storage. L. monocytogenes, mesophiles, Enterobacteriaceae, lactic acid bacteria, Micrococcaceae, molds and yeast counts were evaluated. Additionally, water activity, humidity and pH were determined. L. monocytogenes counts decreased in inoculated sliced chorizo during storage. Packaging conditions and day of storage influenced microbial counts. After 60 days, a significant reduction (p ≤ 0.05) in the initial Listeria contamination levels (3.5. log CFU/g) between 1.1 and 1.46 logarithmic units was achieved in the sausages packaged in modified atmosphere. The highest reductions were observed in slices packaged in 40% CO2/60% N2 after 60 days of storage at 4 °C.

scholarly journals Effect of UV-C Irradiation and Lactic Acid Application on the Inactivation of Listeria monocytogenes and Lactic Acid Bacteria in Vacuum-Packaged Beef

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1217
Author(s):  
Giannina Brugnini ◽  
Soledad Rodríguez ◽  
Jesica Rodríguez ◽  
Caterina Rufo
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Quadratic Model ◽  
Meat Color ◽  
Minimal Impact ◽  
Log Reduction ◽  
Combined Application ◽  
Meat Samples ◽  
Uv C

The objective of this study was to test the effect of the combined application of lactic acid (0–5%) (LA) and UV-C light (0–330 mJ/cm2) to reduce Listeria monocytogenes and lactic acid bacteria (LAB) on beef without major meat color (L *, a *, b *) change and its impact over time. A two-factor central composite design with five central points and response surface methodology (RSM) were used to optimize LA concentration and UV-C dose using 21 meat pieces (10 g) inoculated with L. monocytogenes (LM100A1). The optimal conditions were analyzed over 8 weeks. A quadratic model was obtained that predicted the L. monocytogenes log reduction in vacuum-packed beef treated with LA and UV-C. The maximum log reduction for L. monocytogenes (1.55 ± 0.41 log CFU/g) and LAB (1.55 ± 1.15 log CFU/g) with minimal impact on meat color was achieved with 2.6% LA and 330 mJ/cm2 UV-C. These conditions impaired L. monocytogenes growth and delayed LAB growth by 2 weeks in vacuum-packed meat samples throughout 8 weeks at 4 °C. This strategy might contribute to improving the safety and shelf life of vacuum-packed beef with a low impact on meat color.

Metabiotic Effects of Fusarium spp. on Escherichia coli O157:H7 and Listeria monocytogenes on Raw Portioned Tomatoes

2008 ◽  
Vol 71 (7) ◽  
pp. 1366-1371 ◽  
Author(s):  
ANTONIO BEVILACQUA ◽  
FRANCESCA CIBELLI ◽  
DANIELA CARDILLO ◽  
CLELIA ALTIERI ◽  
MILENA SINIGAGLIA
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Fruits And Vegetables ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction ◽  
Death Time ◽  
Storage Temperatures

The metabiotic effects of Fusarium proliferatum, F. avenaceum, and F. oxysporum on Escherichia coli O157:H7 and Listeria monocytogenes in fresh tomatoes were investigated. Tomatoes were preinoculated with the molds and incubated at 15°C for 7 days; then they were inoculated separately with the pathogens, packaged in air and modified atmosphere (5% O2, 30% CO2, and 65% N2), and stored at 4, 8, and 12°C for 9 days. The cell loads of pathogens and lactic acid bacteria and the pH were evaluated periodically. The data were modeled through some different mathematical models to assess the shoulder length, i.e., the time before the beginning of the exponential death phase, the 1-log reduction time (δ), and the pathogen death time (δstand). The preinoculation of tomatoes with the molds enhanced the survival of E. coli O157:H7 by prolonging shoulder length and δ parameters; this effect, however, was not observed for L. monocytogenes. pH values did not undergo significant changes within the storage time, and the lactic acid bacteria increased from 5 to 7 log CFU/g, without significant differences among the storage temperatures or the packaging atmospheres. The results of this research showed that the use of fresh tomatoes colonized by fusaria (even if the contamination is not visible) could increase significantly the risk of outbreaks due to some pathogens that could be on the surface of fruits and vegetables as a result of cross-contamination at home or incorrect postharvest operations.

scholarly journals Effect of lactic acid bacteria on Listeria monocytogenes infection and innate immunity in rabbits

2020 ◽  
Vol 65 (No. 1) ◽  
pp. 23-30 ◽  
Author(s):  
Heping Zhao ◽  
Feike Zhang ◽  
Jun Chai ◽  
Jianping Wang
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Positive Control ◽  
Negative Control ◽  
Listeriolysin O ◽  
Serum Iga ◽  
Probiotic Lactic Acid Bacteria ◽  
Spleen And Lymph Nodes ◽  
Proinflammatory Factors

The present study aimed to investigate the effect of probiotic lactic acid bacteria (LAB) addition on Listeria monocytogenes translocation and its toxin listeriolysin O (LLO), proinflammatory factors, immune organ indexes and serum immunoglobulins in farmed rabbits. Five treatments included negative control (NC), positive control (PC) with L. monocytogenes infection and supplemental LAB at 3.0 × 10<sup>6 </sup>(low-LAB, L-LAB), 3.0 × 10<sup>8</sup> (medium-LAB, M-LAB) and 3.0 × 10<sup>10 </sup>(high-LAB, H-LAB) CFU/kg of diet, respectively. The LAB was a mixture of equal amounts of Lactobacillus acidophilus (ACCC11073), Lactobacillus plantarum (CICC21863) and Enterococcus faecium (CICC20430). A total of 180 weaned rabbits (negative for L. monocytogenes) were randomly assigned to 5 groups with 6 replicates of 6 rabbits each in response to the 5 treatments. L. monocytogenes infection occurred on the first day of feeding trial and dietary LAB supplementation lasted for 14 days. The results showed that on days 7 and 14 post administration, L. monocytogenes in caecum, liver, spleen and lymph nodes was reduced in M-LAB and H-LAB compared to PC (P &lt; 0.05), and linear and quadratic reducing trends were found in liver on day 7 (P ≤ 0.002). On day 14, mucosa LLO mRNA expression and serum TNFα, IL1β and IFNγ were reduced in the three LAB treatments (P &lt; 0.05), and linear and quadratic trends were found on TNFα and IL1β (P ≤ 0.025); indexes of thymus and spleen, serum IgA and IgG were increased in the LAB treatments (P &lt; 0.05). It is concluded that LAB can be used to alleviate L. monocytogenes infection and to improve the immune function of farmed animals.

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