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.

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 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.

scholarly journals High carbon-di-oxide modified atmospheric packaging on quality of ready-to-eat minimally processed fresh-cut iceberg lettuce

2021 ◽  
Author(s):  
Md. Azizul Haque ◽  
Md. Asaduzzaman ◽  
Md. Sultan Mahomud ◽  
Md. Rizvi Alam ◽  
Alin Khaliduzzaman ◽  
...  
Keyword(s):  
Modified Atmosphere Packaging ◽  
Storage Condition ◽  
Modified Atmosphere ◽  
High Carbon ◽  
Modified Atmospheric Packaging ◽  
Iceberg Lettuce ◽  
Microbial Development ◽  
Fresh Cut ◽  
Intact Surface

AbstractFresh-cut lettuce is a very well-known salad for today's routines because it obliges minimal preparation to minimize the loss of health beneficial vitamins, minerals, antioxidants and other phytochemicals. It is a prodigious challenge to serve its consumers fresh. Quality of freshly processed lettuce under high CO2 modified atmosphere packaging (MAP) has been investigated as a realistic alternative technique for its preservation. Storage under high CO2 atmospheric treatments exhibited a significant impact in microbial development, electrolyte leakage, volatile metabolites and sensory quality of fresh-cut iceberg lettuce. This storage condition (MAP 1: 5 kPa O2 and 20 kPa CO2 balanced by N2 at 7 °C for 6 days) inhibited the growth of mesophilic bacteria and yeasts; delayed the enzymatic browning (cut-edges and intact surface) of fresh-cut iceberg lettuce and overall visual quality was also in acceptance limit. The development of off-odors was perceived in high CO2 MAP as a consequence of volatiles (ethanol and acetaldehyde) accumulation which was persisted at an inexcusable level during 6 days of storage periods.

scholarly journals Combined Effect of Dipping in Oxalic or in Citric Acid and Low O2 Modified Atmosphere, to Preserve the Quality of Fresh-Cut Lettuce during Storage

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 988
Author(s):  
Bernardo Pace ◽  
Imperatrice Capotorto ◽  
Michela Palumbo ◽  
Sergio Pelosi ◽  
Maria Cefola
Keyword(s):  
Citric Acid ◽  
Respiration Rate ◽  
Modified Atmosphere Packaging ◽  
Packaging Material ◽  
Combined Effect ◽  
Modified Atmosphere ◽  
Iceberg Lettuce ◽  
Fresh Cut ◽  
Main Factor

Leaf edge browning is the main factor affecting fresh-cut lettuce marketability. Dipping in organic acids as well as the low O2 modified atmosphere packaging (MAP), can be used as anti-browning technologies. In the present research paper, the proper oxalic acid (OA) concentration, able to reduce respiration rate of fresh-cut iceberg lettuce, and the suitable packaging materials aimed to maintaining a low O2 during storage, were selected. Moreover, the combined effect of dipping (in OA or in citric acid) and packaging in low O2 was investigated during the storage of fresh-cut iceberg lettuce for 14 days. Results showed a significant effect of 5 mM OA on respiration rate delay. In addition, polypropylene/polyamide (PP/PA) was select as the most suitable packaging material to be used in low O2 MAP. Combining OA dipping with low O2 MAP using PP/PA as material, resulted able to reduce leaf edge browning, respiration rate, weight loss and electrolyte leakage, preserving the visual quality of fresh-cut lettuce until 8 days at 8 °C.

scholarly journals Growth Potential of Listeria monocytogenes in Three Different Salmon Products

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1048 ◽  
Author(s):  
Corinne Eicher ◽  
Andres Ruiz Subira ◽  
Sabrina Corti ◽  
Arnulf Meusburger ◽  
Roger Stephan ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Challenge Test ◽  
High Growth ◽  
Growth Potential ◽  
High Concentration ◽  
Food Borne ◽  
Smoked Salmon ◽  
Good Manufacturing Practices ◽  
Challenge Tests ◽  
Low Levels

Cold smoked salmon and sushi salmon have been implicated in outbreaks of listeriosis. We performed challenge tests and a durability study with Listeria monocytogenes on different salmon products to determine the growth potential of this important food-borne pathogen. Data from the challenge test showed a significant growth potential of L. monocytogenes on all of the tested salmon products, with faster growth in sushi salmon than in cold smoked salmon. In identical products that were naturally contaminated at low levels, the durability study did not confirm a high growth potential, possibly due to interactions with competing microflora. The injection of sodium lactate (NaL) at a high concentration (30%) into cold smoked salmon significantly reduced the growth potential of L. monocytogenes. In addition to good manufacturing practices, the injection of higher concentrations of NaL may therefore be a useful additional hurdle to prevent growth of L. monocytogenes to high numbers in the tested salmon products.

scholarly journals Effects of Gamma Irradiation, Modified Atmosphere Packaging, and Delay of Irradiation on Quality of Fresh-cut Iceberg Lettuce

HortScience ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 273-277 ◽  
Author(s):  
Xuetong Fan ◽  
Kimberly J.B. Sokorai
Keyword(s):  
Gamma Irradiation ◽  
Modified Atmosphere Packaging ◽  
Visual Quality ◽  
Modified Atmosphere ◽  
Cut Edge ◽  
Quality Deterioration ◽  
Iceberg Lettuce ◽  
Fresh Cut ◽  
Tissue Browning

This study was conducted to investigate the effect of modified atmosphere packaging (MAP) and delay of irradiation application on the quality of cut Iceberg lettuce. Overall visual quality and tissue browning of cut lettuce were evaluated using a scale of 9 to 1, whereas texture was analyzed instrumentally during 14 days of storage at 4 °C. Results showed that irradiation (0.5 and 1.0 kGy) of cut lettuce induced tissue browning when stored in air; however, when cut lettuce was stored in MAP, irradiated lettuce had better appearance than the non-irradiated ones as a result of lower O2 levels in the packages of irradiated samples compared with the levels in control packages. In general, irradiation at doses of 0.5 and 1.0 kGy did not affect firmness of the lettuce. After 14 days of MAP storage, overall visual quality of non-irradiated samples had a score of ≈4, a score below the limit of sales appeal, whereas the two irradiated samples had scores of 6.5 to 7.9, indicating the irradiated samples had a fair to good quality. Delaying irradiation by 1 day after preparation of cut lettuce did not significantly (P > 0.05) affect cut edge browning, surface browning, or overall visual quality compared with lettuce irradiated immediately after preparation. Our results suggest that MAP is essential to minimize quality deterioration caused by irradiation.

Effects of Microbial Inhibitors and Modified Atmosphere Packaging on Growth of Listeria monocytogenes and Salmonella enterica Typhimurium and on Quality Attributes of Injected Pork Chops and Sliced Cured Ham

2006 ◽  
Vol 69 (11) ◽  
pp. 2671-2680 ◽  
Author(s):  
ANDREW R. MICHAELSEN ◽  
JOSEPH G. SEBRANEK ◽  
JAMES S. DICKSON
Keyword(s):  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Modified Atmosphere Packaging ◽  
Inhibitory Effect ◽  
Modified Atmosphere ◽  
High Co2 ◽  
Pork Products ◽  
C Storage ◽  
Potassium Lactate ◽  
High Concentrations

This study was designed to determine the inhibitory effects of modified atmosphere packaging (MAP), both alone and in combination with potassium lactate and sodium diacetate (PLSD), on selected pathogens common to pork products. Effects of the treatments on product quality also were assessed. The hypothesis was that high-CO2 MAP would increase the effectiveness of PLSD for inhibition of pork pathogens. Fresh chops from untreated pork loins and loins that were injected with PLSD were inoculated with Salmonella enterica Typhimurium, and slices of untreated hams and hams that were injected with PLSD were inoculated with Listeria monocytogenes. The samples were subjected to vacuum packaging (VP) or MAP with high concentrations (99.5 to 100%) of CO2. Pathogens were enumerated periodically during storage at 4 and 10°C. Storage of pork chops at 4°C slowed the growth of Salmonella Typhimurium, and there was little difference in pathogen numbers between VP and MAP samples. L. monocytogenes growth on ham slices at 4°C was inhibited for up to 28 days by all of the treatments, but after 28 days, the VP-PLSD treatment had a greater inhibitory effect than did the other treatments. At 10°C, the PLSD and MAP treatments each effectively inhibited the growth of the pathogens on pork chops and ham slices when compared with controls (VP). However, the results obtained with MAP plus PLSD at 10°C were not different from those obtained with either MAP or PLSD alone. Therefore, the hypothesis was not supported; the high-CO2 atmosphere of the MAP did not increase the effectiveness of PLSD for inhibition of pathogens.

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