scholarly journals Growth Potential of Listeria monocytogenes in Chef-Crafted Ready-to-Eat Fresh Cheese-Filled Pasta Meal Stored in Modified Atmosphere Packaging

2019 ◽  
Vol 82 (9) ◽  
pp. 1546-1552
Author(s):  
MARCELLO TREVISANI ◽  
ALESSANDRA DE CESARE ◽  
SILVA VITALI ◽  
ROCCO MANCUSI ◽  
FEDERICA BOVO ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Modified Atmosphere Packaging ◽  
Growth Potential ◽  
Modified Atmosphere ◽  
Initial Growth ◽  
Maximum Cell Density ◽  
The Difference

ABSTRACT This study evaluated the growth of lactic acid bacteria (LAB) in a fresh, filled-pasta meal, stored in modified atmosphere packaging and the influence of lactic acid (LA) and pH on the growth of Listeria monocytogenes (Lm). Samples were taken from three lots manufactured by a local catering company and stored at both 6 and 14°C. LAB numbers, LA concentration, pH, and the presence of Lm were evaluated at 1, 4, 6, 8, 10, 12, and 14 days of shelf life and the undissociated LA concentration ([LA]) was calculated. The LAB maximum cell density was greater in the products stored at 14°C than those stored at 6°C (10.1 ± 1.1 versus 5.6 ± 1.5 log CFU/g) and [LA] at 14 days was 9 to 21 ppm at 6°C and 509 to 1,887 ppm at 14°C. Challenge tests were made to evaluate the interference of LAB and [LA] on Lm growth. Aliquots of the samples (25 g) were inoculated at 1 to 10 days of shelf life and incubated at 9°C for 7 days, and the difference between Lm numbers at the end and at the beginning of the test (δ) was calculated. Logistic regression was used to model the probability of growth of Lm as a function of LAB and [LA]. The products inoculated at 1 day of shelf life had δ values between 4.2 and 5.6 log CFU/g, but the growth potential was progressively reduced during the shelf life. Lm growth was never observed in the products stored at 14°C. In those stored at 6°C, it grew only in the samples with LAB <5.7 log CFU/g. LAB interaction might thus inhibit the growth of Lm in temperature-abused products and limit its growth in refrigerated products. Logistic regression estimated that the probability of Lm growth was <10% if LAB was >6.6 log CFU/g or log[LA] was >2.2 ppm. The growth or inactivation kinetic of Lm was investigated with a homogenate of three samples with LAB numbers close to the maximum population density. After an initial growth, a subsequent reduction in the number of Lm was observed. This means that the maximum numbers of Lm might not be detected at the end of the product shelf life.

Influence of argon modified atmosphere packaging on the growth potential of strains of Listeria monocytogenes and Escherichia coli

Food Control ◽  
2016 ◽  
Vol 59 ◽  
pp. 513-523 ◽  
Author(s):  
Victoria Heinrich ◽  
Marija Zunabovic ◽  
Lisa Nehm ◽  
Johannes Bergmair ◽  
Wolfgang Kneifel
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Modified Atmosphere Packaging ◽  
Growth Potential ◽  
Modified Atmosphere

scholarly journals Growth Potential of Listeria monocytogenes on Refrigerated Spinach and Rocket Leaves in Modified Atmosphere Packaging

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1211
Author(s):  
Paul Culliney ◽  
Achim Schmalenberger
Keyword(s):  
Listeria Monocytogenes ◽  
Modified Atmosphere Packaging ◽  
Growth Curves ◽  
High Growth ◽  
Food Product ◽  
Growth Potential ◽  
Modified Atmosphere ◽  
Visual Appearance ◽  
Iceberg Lettuce ◽  
Duration Of Storage

Minimally processed ready-to-eat (RTE) vegetables are increasingly consumed for their health benefits. However, they also pose a risk of being ingested with food-borne pathogens. The present study investigated the ability of RTE spinach and rocket to support the growth of Listeria monocytogenes as previous studies provided contradicting evidence. Findings were compared to growth on iceberg lettuce that has repeatedly been shown to support growth. Products were inoculated with a three-strain mix of L. monocytogenes at 10 and 100 cfu g−1 and stored in modified atmosphere (4 kPa O2, 8 kPa CO2) at 8 °C over 7–9 days. Spinach demonstrated the highest growth potential rate of 2 to 3 log10 cfu g−1 over a 9-day period with only marginal deterioration in its visual appearance. Growth potential on rocket was around 2 log10 cfu g−1 over 9 days with considerable deterioration in visual appearance. Growth potential of iceberg lettuce was similar to that of rocket over a 7-day period. Growth curves fitted closely to a linear growth model, indicating none to limited restrictions of growth over the duration of storage. The high growth potentials of L. monocytogenes on spinach alongside the limited visual deterioration highlight the potential risks of consuming this raw RTE food product when contaminated.

scholarly journals Development of a scientific study for accessing the criteria under Commission Regulation (EC) 2073/2005 on traditional Slovak sheep cheese "bryndza"

2011 ◽  
Vol 29 (No. 1) ◽  
pp. 31-34
Author(s):  
L. Cabanová ◽  
O. Škuntová ◽  
D. Matisová ◽  
M. Pipová
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Laboratory Tests ◽  
Growth Potential ◽  
Life Study ◽  
Physico Chemical ◽  
Commission Regulation ◽  
The Difference ◽  
Microbiological Analyses ◽  
Positive Results

A scientific shelf-life study for Listeria monocytogenes in the typical Slovak cheese "bryndza" was performed in accordance with the requirements of the Commission Regulation (EC) 2073/2005. Based on the previous positive findings of L. monocytogenes in the final products, the producer decided to perform laboratory tests, the results of which would allow him a different evaluation of these positive results. Both the physico-chemical (pH, a<sub>w)</sub> and microbiological examinations of "bryndza" cheese stored at 5.8&ndash;6.2&deg;C were performed every two days till the end of the product shelf-life (7 days). Microbiological analyses were performed after artificial contamination of the final product with a mixture of three L. monocytogenes strains. The growth potential of L. monocytogenes was calculated as the difference in the counts of this bacterium between the last day and the first day of the test. The Slovak traditional "bryndza" cheese has been found not to support the growth of L. monocytogenes. Thus, the counts of L. monocytogenes must not exceed 50 CFU/g at the beginning and 20 CFU/g at the end of the product shelf-life in order to ensure its safety for the consumer.

Combined Effect of Natural Essential Oils, Modified Atmosphere Packaging, and Gamma Radiation on the Microbial Growth on Ground Beef

2008 ◽  
Vol 71 (6) ◽  
pp. 1237-1243 ◽  
Author(s):  
M. TURGIS ◽  
J. HAN ◽  
J. BORSA ◽  
M. LACROIX
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Essential Oils ◽  
Shelf Life ◽  
Pathogenic Bacteria ◽  
Combined Treatment ◽  
Modified Atmosphere Packaging ◽  
Ground Beef ◽  
Aerobic Bacteria ◽  
Modified Atmosphere

Selected Chinese cinnamon, Spanish oregano, and mustard essential oils (EOs) were used in combination with irradiation to evaluate their ability to eliminate pathogenic bacteria and extend the shelf life of medium-fat-content ground beef (23% fat). Shelf life was defined as the time when the total bacterial count reached 107 CFU/g. The shelf life of ground beef was determined for 28 days at 4°C after treatment with EOs. The concentrations of EOs were predetermined such that sensory properties of cooked meat were maintained: 0.025% Spanish oregano, 0.025% Chinese cinnamon, and 0.075% mustard. Ground beef samples containing EOs were then packaged under air or a modified atmosphere and irradiated at 1.5 kGy. Ground beef samples (10 g) were taken during the storage period for enumeration of total mesophilic aerobic bacteria, Escherichia coli, Salmonella, total coliforms, lactic acid bacteria, and Pseudomonas. Mustard EO was the most efficient for reducing the total mesophilic aerobic bacteria and eliminating pathogenic bacteria. Irradiation alone completely inhibited the growth of total mesophilic aerobic and pathogenic bacteria. The combination of irradiation and EOs was better for reducing lactic acid bacteria (mustard and cinnamon EOs) and Pseudomonas (oregano and mustard EOs). The best combined treatment for extending the shelf life of ground beef for up to 28 days was EO plus irradiation (1.5 kGy) and modified atmosphere packaging.

scholarly journals Growth potential of Listeria monocytogenes in veal tartare

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Simone Stella ◽  
Cristian Bernardi ◽  
Erica Tirloni
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Shelf Life ◽  
Challenge Test ◽  
Growth Potential ◽  
Daily Maximum ◽  
Initial Concentration ◽  
Spoilage Bacteria ◽  
Sampling Times

In the present study the growth potential of Listeria monocytogenes in veal tartare was evaluated. A challenge test was performed on three tartare batches at 8°C, aiming to evaluate the growth potential of the pathogen. The data indicated the absence of a significant growth (δ<0.5 log cfu/g) during the entire period. When considering intermediate sampling times, an increase of 0.56 log cfu/g was detected after five days of storage in one of the batches. Microflora of veal tartare was dominated by lactic acid bacteria, that increased gradually during the trial, reaching counts up to 7 Log CFU/g in two of the three batches considered. Spoilage bacteria were present (especially Pseudomonas spp., yeasts and Enterobacteriaceae) but in very low counts and with a limited increase during the period considered. Finally, daily maximum tolerable L. monocytogenes counts were calculated to highlight the maximum acceptable load to avoid the overcoming of the legal limit of 100 CFU/g: a total increase of 0.95 log cfu/g in 12 days of shelf-life was estimated, obtaining a “safety initial concentration” at t0 of 10 CFU/g of the pathogen.

Botulism Challenge Studies of a Modified Atmosphere Package for Fresh Mussels: Inoculated Pack Studies

2012 ◽  
Vol 75 (6) ◽  
pp. 1157-1166 ◽  
Author(s):  
C. R. NEWELL ◽  
LI MA ◽  
MICHAEL DOYLE
Keyword(s):  
Lactic Acid ◽  
Botulinum Toxin ◽  
Shelf Life ◽  
Storage Temperature ◽  
Modified Atmosphere Packaging ◽  
Toxin Production ◽  
Modified Atmosphere ◽  
Gas Composition ◽  
Plate Counts ◽  
Sampling Times

A series of botulism challenge studies were performed to determine the possibility of production of botulinum toxin in mussels (Mytilus edulis) held under a commercial high-oxygen (60 to 65% O2), modified atmosphere packaging (MAP) condition. Spore mixtures of six strains of nonproteolytic Clostridium botulinum were introduced into mussel MAP packages receiving different packaging buffers with or without the addition of lactic acid bacteria. Dye studies and package flipping trials were conducted to ensure internalization of spores by packed mussels. Inoculated mussel packages were stored at normal (4°C) and abusive (12°C) temperatures for 21 and 13 days, respectively, which were beyond the packaged mussels' intended shelf life. Microbiological and chemical analyses were conducted at predetermined intervals (a total of five sampling times at each temperature), including total aerobic plate counts, C. botulinum counts, lactic acid bacterial counts, package headspace gas composition, pH of packaging buffer and mussel meat, and botulinum toxin assays of packaging buffer and mussel meat. Results revealed that C. botulinum inoculated in fresh mussels packed under MAP packaging did not produce toxin, even at an abusive storage temperature and when held beyond their shelf life. No evidence was found that packaging buffers or gas composition influenced the lack of botulinum toxin production in packed mussels.

Combined Effects of Modified Atmosphere Packaging and Thymol for Prolonging the Shelf Life of Caprese Salad

2007 ◽  
Vol 70 (3) ◽  
pp. 722-728 ◽  
Author(s):  
ANTONIO BEVILACQUA ◽  
MARIA ROSARIA CORBO ◽  
MILENA SINIGAGLIA
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Shelf Life ◽  
Modified Atmosphere Packaging ◽  
Lag Phase ◽  
Modified Atmosphere ◽  
Combined Effects ◽  
Mozzarella Cheese ◽  
Natural Microflora ◽  
Kinetics Of

The aim of this study was to investigate the influence of packaging atmosphere and a thymol dipping solution on the shelf life of caprese salad. Caprese salad was prepared with sliced tomatoes and mozzarella cheese. The samples were pretreated by dipping in a 400-ppm thymol solution and then packaged under air or under a modified atmosphere (65% N2, 30% CO2, and 5% O2). Changes in natural microflora of mozzarella and tomato, the O2 and CO2 in the head space, pH, and sensory characteristics were monitored during storage. The combination of the thymol dip and the modified atmosphere decreased the coliform populations in caprese salad from 5.65 to 4.23 log CFU·g−1 and extended the shelf life from 3.77 to 12 days. A decrease in the concentration of Pseudomonadaceae from 7.03 to 5.09 log CFU·g−1 was observed, and the lag phase was prolonged to approximately 3 days. The combination of the modified atmosphere and thymol did not affect the growth kinetics of lactic acid bacteria and enterococci, thus preserving the function of mozzarella cheese in the salad.

scholarly journals Effects of Modified Atmosphere Packaging on the Microbiological Properties of Fresh Common Carp (Cyprinus carpio L.)

2010 ◽  
Vol 79 (9) ◽  
pp. S93-S100 ◽  
Author(s):  
Katarína Hudecová ◽  
Hana Buchtová ◽  
Iva Steinhauserová
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Common Carp ◽  
Cyprinus Carpio ◽  
Modified Atmosphere Packaging ◽  
Coliform Bacteria ◽  
Modified Atmosphere ◽  
E Coli ◽  
Air Control ◽  
Microbiological Properties

The aim of this study was to compare the growth rate of total viable counts (TVC), psychrotrophic viable counts (PVC), coliform bacteria and E. coli in portions of fresh common carp (Cyprinus carpio L.) under two different modified atmosphere packaging (experimental MAP1: 70% N2/30% CO2; experimental MAP2: 80% O2/20% CO2) and air (control samples) stored at +4 ± 0.5 °C, and to determine their shelf life. The presence of pathogens (Salmonella spp. and Listeria monocytogenes) was also surveyed in this study. A total of 360 portions from 90 common carp were examined. Laboratory analyses were performed on storage day 0 (production day) and days 3, 7 and 10. As compared to air packaging, the numbers of TVC and PVC were significantly lower (p < 0.001) in both modified atmosphere packaging (MAP) on storage days 7 and 10; coliform bacteria were significantly lower only on day 7. E. coli counts in fresh carp during storage were generally low, showing levels of < 1 log cfu/g. Salmonella spp. and Listeria monocytogenes were not detected in any of the examined samples. All the strains of Listeria spp. were identified as Listeria innocua. According to TVC values and sensory changes, the shelf life of carp portions was determined as 6 days in MAP1, 8 days in MAP2 and 3 days in air.

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