scholarly journals Analysis of the Bioprotective Potential of Different Lactic Acid Bacteria Against Listeria monocytogenes in Cold-Smoked Sea Bass, a New Product Packaged Under Vacuum and Stored at 6 ± 2°C

2021 ◽  
Vol 12 ◽  
Author(s):  
Lucilla Iacumin ◽  
Giorgia Cappellari ◽  
Michela Pellegrini ◽  
Marco Basso ◽  
Giuseppe Comi
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Storage Temperature ◽  
Enrichment Culture ◽  
Starter Culture ◽  
Sea Bass ◽  
New Product ◽  
Fish Products ◽  
Smoked Fish ◽  
Different Strains

The aim of the work was to monitor the presence of Listeria monocytogenes in cold-smoked fish products (trout, salmon, and sea bass) marketed in Italy. Cold-smoked sea bass is a new product that has not yet been commercialized and was collected from the production facility. Monitoring data have shown that cold-smoked products can be contaminated by L. monocytogenes, the presence of which has been highlighted mainly by enrichment culture (presence in 25 g). The isolated Listeria were serotyped and belonged mainly to low-virulence serotypes (1/2c), followed by serotypes 1/2a, 1/2b, and 4b. Furthermore, considering the ability of L. monocytogenes to grow in these products due to their chemical–physical characteristics (pH > 6.0, Aw > 0.97) and long shelf life at 4°C, an additional aim was to verify the activity of different bioprotective starters, including Lactilactobacillus sakei (LAK-23, Sacco srl, Via Alessandro Manzoni 29/A, 22071 Cadorago, CO, Italy), Carnobacterium spp., Lacticaseibacillus casei (SAL 106), and Lacticaseibacillus paracasei (SAL 211), in cold-smoked sea bass. All starters were bacteriocin producers. For this experiment, smoked sea bass samples were intentionally inoculated with a mixture of three different strains of L. monocytogenes and of each starter culture. After inoculation, the smoked sea bass were vacuum-packed and stored at 6 ± 2°C for 60 days, simulating the typical abuse storage temperature of markets and home refrigerators. At 0, 15, 30, 45, and 60 days, the sea bass samples were analyzed to evaluate the effectiveness of the starters against L. monocytogenes. Listeria monocytogenes growth was prevented only by the addition of the LAK-23 starter. Indeed, at the end of the shelf life, the amount of L. monocytogenes observed was similar to that in the inoculum. Consequently, the use of this starter can allow the inclusion of cold-smoked sea bass or smoked fish products in category 1.3 of Regolamento CE 2073/2005, which are products that do not support the growth of this microorganism. Finally, the activity of the LAK-23 starter did not produce an off flavor or off odor in the smoked sea bass.

scholarly journals Effect of Potassium Lactate and a Potassium Lactate–Sodium Diacetate Blend on Listeria monocytogenes Growth in Modified Atmosphere Packaged Sliced Ham

2007 ◽  
Vol 70 (10) ◽  
pp. 2297-2305 ◽  
Author(s):  
L. A. MELLEFONT ◽  
T. ROSS
Keyword(s):  
Listeria Monocytogenes ◽  
Organic Acid ◽  
Shelf Life ◽  
Storage Temperature ◽  
Modified Atmosphere ◽  
Acid Salt ◽  
Potassium Lactate ◽  
Sodium Diacetate ◽  
Potential Inhibitors ◽  
And Storage

Two commercially available organic acid salts, potassium lactate (PURASAL HiPure P) and a potassium lactate–sodium diacetate blend (PURASAL Opti.Form PD 4), were assessed as potential inhibitors of Listeria monocytogenes growth in modified atmosphere packaged (MAP) sliced ham in challenge studies. The influence of the initial inoculation level of L. monocytogenes (101 or 103 CFU g−1) and storage temperature (4 or 8°C) was also examined. The addition of either organic acid salt to MAP sliced ham strongly inhibited the growth of L. monocytogenes during the normal shelf life of the product under ideal refrigeration conditions (4°C) and even under abusive temperature conditions (i.e., 8°C). During the challenge studies and in the absence of either organic acid salt, L. monocytogenes numbers increased by 1,000-fold after 20 days at 8°C and 10-fold after 42 days at 4°C. Both organic acid salt treatments were found to be listeriostatic rather than listericidal. The addition of either organic acid salt to the MAP ham also reduced the growth of indigenous microflora, i.e., aerobic microflora and lactic acid bacteria. The influence of these compounds on the risk of listeriosis in relation to product shelf life is discussed.

Prevalence and Numbers of Listeria monocytogenes in Various Ready-to-Eat Foods over a 5-Year Period in Estonia

2019 ◽  
Vol 82 (4) ◽  
pp. 597-604 ◽  
Author(s):  
JULIA KOSKAR ◽  
TOOMAS KRAMARENKO ◽  
KADRIN MEREMÄE ◽  
MAIU KUNINGAS ◽  
JELENA SÕGEL ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Risk Groups ◽  
Food Samples ◽  
Safety Criterion ◽  
Fish Products ◽  
Product Categories ◽  
Salted Fish ◽  
Smoked Fish ◽  
High Prevalence ◽  
Fish Product

ABSTRACT The prevalence and numbers of Listeria monocytogenes in various categories of ready-to-eat (RTE) food products taken from retail outlets and food industries over a 5-year period are presented. A total of 30,016 RTE food samples were analyzed for L. monocytogenes prevalence, and 3.6% were found to be positive. The highest prevalence was found for RTE fish and fish products (11.6%), especially for lightly salted and cold-smoked fish products. The overall prevalence of L. monocytogenes in other food categories was low, within the range of 0 to 3.9%. In addition, 14,342 RTE food samples were analyzed to determine the numbers of L. monocytogenes. A food safety criterion of 100 CFU/g was exceeded for 0.3% of RTE food samples. Samples most often exceeding the legal safety limit were from the RTE salted and cold-smoked fish product categories. High prevalence, 28.6 and 26.5%, respectively, and high numbers of L. monocytogenes among salted fish and cold-smoked fish products indicate a risk of listeriosis, especially for susceptible risk groups. The results of the current study can be used at both the national and the international levels to update the perception of the L. monocytogenes risk deriving from RTE foods. HIGHLIGHTS

Antilisterial Activity of a Carnobacterium piscicola Isolated from Brazilian Smoked Fish (Surubim [Pseudoplatystoma sp.]) and Its Activity against a Persistent Strain of Listeria monocytogenes Isolated from Surubim

2005 ◽  
Vol 68 (10) ◽  
pp. 2068-2077 ◽  
Author(s):  
VIRGÍNIA F. ALVES ◽  
ELAINE C. P. DE MARTINIS ◽  
MARIA TERESA DESTRO ◽  
BIRTE FONNESBECH VOGEL ◽  
LONE GRAM
Keyword(s):  
Listeria Monocytogenes ◽  
Freshwater Fish ◽  
Random Amplified Polymorphic Dna ◽  
Model Systems ◽  
Fish Products ◽  
Tropical Regions ◽  
Smoked Fish ◽  
Smoked Salmon ◽  
Carnobacterium Piscicola

Data on the prevalence and growth of Listeria monocytogenes in lightly preserved fish products from subtropical and tropical regions are very scarce. Our research describes L. monocytogenes that was detected in 5% of the packages of cold-smoked surubim, a native Brazilian freshwater fish that we analyzed, and shows that the strains isolated were of the same random amplified polymorphic DNA subtype as the strains that were isolated from the same factory 4 years earlier. A bacteriocinogenic strain of Carnobacterium piscicola (strain C2), isolated from vacuum-packed cold-smoked surubim, and two C. piscicola strains, isolated from vacuum-packed, cold-smoked salmon, were capable of limiting or completely inhibiting the growth of an L. monocytogenes (strain V2) isolated from surubim in fish peptone model systems incubated at 10°C. Mono-cultures of L. monocytogenes reached 108 CFU/ml (g), whereas the growth of L. monocytogenes was completely inhibited by C. piscicola C2. The bacteriocinogenic C. piscicola A9b+ and its nonbacteriocinogenic mutant A9b− reduced maximum Listeria levels by 2 to 3 log units. Both bacteriocinogenic C. piscicola strains prevented listerial growth in cold-smoked fish juices (surubim and salmon). Although the carnobacteria grew poorly on cold-smoked surubim at 10°C, the strains were able to reduce maximum Listeria counts by 1 to 3 log units in an artificially inoculated product (surubim). We conclude that Brazilian smoked fish products harbor L. monocytogenes and should be stabilized against the growth of the organism. C. piscicola C2 has the potential for use as a bioprotective culture in surubim and other lightly preserved fish, but further studies are required to optimize its effect.

scholarly journals Identification and serotyping of Listeria monocytogenes, isolated from various salmon products, sold in retail market in Lithuania

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Ineta Simonavičienė ◽  
Gintarė Zakariene ◽  
Aušra Lozoraitytė ◽  
Gintarė Zaborskienė ◽  
Gediminas Gerulis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Multiplex Pcr ◽  
Local Market ◽  
Microbiological Analysis ◽  
Retail Market ◽  
Fish Products ◽  
Smoked Fish ◽  
Smoked Salmon ◽  
Study Results ◽  
Fish Product

Cold smoked salmon products (belly flaps, pieces, fillet, and loin) obtained from the retail market in Lithuania were tested for the presence of L. monocytogenes. It was found that contamination of the cold smoked fish products with Listeria spp. depends on the type of the product. Contamination with listeria in salmon belly flaps was 7.5 times higher than in the loin (P<0.05), 1.8 times higher than in the pieces (P<0.05) and 30 times higher than in the fillet (P<0.05). Microbiological analysis showed that 32.5% (P<0.05) of the fish product samples were infected with L. monocytogenes, while multiplex PCR confirmed 31.25% positive samples (P<0.01). According to the study results, L. monocytogenes strains were divided into two serotypes: 4b (94.6%) and 1/2a (5.4%). High contamination of the products with Listeria spp. showed that cold smoked salmon products, sold in local market, can be a reason of human listeriosis in Lithuania.

Safety-Based Shelf Life Model for Frankfurters Based on Time To Detect Listeria monocytogenes with Initial Inoculum below Detection Limit

2009 ◽  
Vol 72 (9) ◽  
pp. 1878-1884 ◽  
Author(s):  
AMIT PAL ◽  
THEODORE P. LABUZA ◽  
FRANCISCO DIEZ-GONZALEZ
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Storage Temperature ◽  
Selective Medium ◽  
Inoculum Size ◽  
Quantitative Risk Assessment ◽  
Batch Size ◽  
Inoculum Level ◽  
Initial Inoculum ◽  
Life Model

The growth of Listeria monocytogenes inoculated on frankfurters at four inoculum levels (0.1, 0.04, 0.01, and 0.007 CFU/g) was examined at 4, 8, and 12°C until the time L. monocytogenes populations reached a detectable limit of at least 2 CFU/g. A scaled-down assumption was made to simulate a 25-g sample from a 100-lb batch size in a factory setting by using a 0.55-g sample from a 1,000-g batch size in a laboratory. Samples of 0.55 g were enriched in PDX-LIB selective medium, and presumptive results were confirmed on modified Oxford agar. Based on the time to detect (TTD) from each inoculum level and at each temperature, a shelf life model was constructed to predict the detection or risk levels reached by L. monocytogenes on frankfurters. The TTD increased with reductions in inoculum size and storage temperature. At 4°C the TTDs (±standard error) observed were 42.0 ± 1.0, 43.5 ± 0.5, 50.7 ± 1.5, and 55.0 ± 3.0 days when the inoculum sizes were 0.1, 0.04, 0.01, and 0.007 CFU/g, respectively. From the same corresponding inoculum sizes, the TTDs at 8°C were 4.5 ± 0.5, 6.5 ± 0.5, 7.0 ± 1.0, and 8.5 ± 0.5 days. Significant differences (P &lt; 0.05) between TTDs were observed only when the inoculum sizes differed by at least 2 log. On a shelf life plot of ln(TTD) versus temperature, the Q10 (increase in TTD for a 10°C increase in temperature) values ranged from 24.5 to 44.7 and with no significant influence from the inoculum densities. When the observed TTDs were compared with the expected detection times based on the data obtained from a study with an inoculum size of 10 to 20 CFU/g, significant deviations were noted at lower inoculum levels. These results can be valuable in designing a safety-based shelf life model for frankfurters and in performing quantitative risk assessment of listeriosis at low and practical contamination levels.

Fate of Listeria monocytogenes, Salmonella Typhimurium DT104, and Escherichia coli O157:H7 in Labneh as a Pre- and Postfermentation Contaminant

2000 ◽  
Vol 63 (5) ◽  
pp. 608-612 ◽  
Author(s):  
MOHSEN S. ISSA ◽  
ELLIOT T. RYSER
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Storage Temperature ◽  
Starter Culture ◽  
Salt Content ◽  
Health Concern ◽  
Escherichia Coli O157 ◽  
E Coli

Commercially pasteurized milk (∼2% milkfat) was heated at 85 to 87°C/30 min, inoculated to contain 2,000 to 6,000 CFU/ml of Listeria monocytogenes, Salmonella Typhimurium DT104, or Escherichia coli O157:H7, cultured at 43°C for 4 h with a 2.0% (wt/wt) commercial yogurt starter culture, stored 12 to 14 h at 6°C, and centrifuged to obtain a Labneh-like product. Alternatively, traditional salted and unsalted Labneh was prepared using a 3.0% (wt/wt) starter culture inoculum, similarly inoculated after manufacture with the aforementioned pathogens, and stored at 6°C and 20°C. Throughout fermentation, Listeria populations remained unchanged, whereas numbers of Salmonella increased 0.33 to 0.47 logs during the first 2 h of fermentation and decreased thereafter. E. coli populations increased 0.46 to 1.19 logs during fermentation and remained that these levels during overnight cold storage. When unsalted and salted Labneh were inoculated after manufacture, Salmonella populations decreased &gt;2 logs in all samples after 2 days, regardless of storage temperature, with the pathogen no longer detected in 4-day-old samples. Numbers of L. monocytogenes decreased from 2.48 to 3.70 to &lt;1.00 to 1.95 logs after 2 days with the pathogen persisting up to 15 days in one lot of salted/unsalted Labneh stored at 6°C. E. coli O157:H7 populations decreased from 3.39 to 3.7 to &lt;1.00 to 2.08 logs during the first 2 days, with the pathogen no longer detected in any 4-dayold samples. Inactivation rates for all three pathogens in Labneh were unrelated to storage temperature or salt content. Unlike L. monocytogenes that persisted up to 15 days in Labneh, rapid inactivation of Salmonella Typhimurium DT104 and E. coli O157:H7 suggests that these emerging foodborne pathogens are of less public health concern in traditional Labneh.

scholarly journals Application of Liquid Smoke from Coconut Shell in Tandipang (Dussumeiria Acutta) Smoked Fish To Extend Shelf Life

2020 ◽  
Vol 12 (2) ◽  
pp. 315
Author(s):  
Dyah Ayu Rakhmayeni ◽  
Tatty Yuniarti ◽  
Sukarno Sukarno
Keyword(s):  
Activation Energy ◽  
Shelf Life ◽  
Room Temperature ◽  
Plate Count ◽  
Fish Products ◽  
Smoked Fish ◽  
Liquid Smoke ◽  
Quality Degradation ◽  
Total Plate Count ◽  
Different Temperatures

Highlightaw on smoked tandipang fish analyzed.Peroxide value on smoked tandipang fish analyzed.TPC on smoked tandipang fish analyzed.The shelf life of liquid smoked tandipangfish stored at 27o C was obtained the value of t = 23.2 in units of weeks or 5.8 months of storage.AbstractFumigation using liquid smoke produces smoked fish products with a smoky flavor character and can increase shelf life. The research objective was to determine the shelf life of the tandipang fish which was processed using liquid smoking. The test was carried out by storing smoked fish in an incubator at different temperatures 30 °C, 40 °C, and 50 °C with three replications for 5 weeks (35 days). The samples prepared at each temperature were kept in an incubator for five weeks. The parameters tested for estimating shelf life are using the test data aW (activity water), peroxide number, and TPC (total plate count). The three parameters are selected by one parameter to calculate the shelf life of liquid smoked tandipang fish which is considered to greatly affect the quality degradation during storage. The aw parameter is used to determine the shelf life because it has a high R2 value with an activation energy of 86972.75 J / mol.K. Estimation of shelf life of liquid cured fish at room temperature using aw parameter is 23.2 weeks or 5.8 months.

Time temperature integrators for monitoring the shelf life of ready-to-eat chilled smoked fish products

2019 ◽  
Vol 22 ◽  
pp. 100403 ◽  
Author(s):  
Marianna Giannoglou ◽  
Anna-Maria Evangelopoulou ◽  
Nikolas Perikleous ◽  
Christina Baclori ◽  
Theofania Tsironi ◽  
...  
Keyword(s):  
Shelf Life ◽  
Fish Products ◽  
Smoked Fish

Fate of Listeria monocytogenes, Pathogenic Yersinia enterocolitica, and Escherichia coli O157:H7 gfp+ in Ready-to-Eat Salad during Cold Storage: What Is the Risk to Consumers?

2017 ◽  
Vol 80 (2) ◽  
pp. 204-212 ◽  
Author(s):  
Karin Söderqvist ◽  
Susanne Thisted Lambertz ◽  
Ivar Vågsholm ◽  
Lise-Lotte Fernström ◽  
Beatrix Alsanius ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Yersinia Enterocolitica ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Chicken Meat ◽  
Leafy Vegetables ◽  
Escherichia Coli O157 ◽  
Pathogenic Yersinia

ABSTRACT In this study, we investigated the fate of Listeria monocytogenes, pathogenic Yersinia enterocolitica, and Escherichia coli O157:H7 gfp+ inoculated in low numbers into ready-to-eat baby spinach and mixed-ingredient salad (baby spinach with chicken meat). Samples were stored at recommended maximum refrigerator temperature (8°C in Sweden) or at an abuse temperature (15°C) for up to 7 days. Mixed-ingredient salad supported considerable growth when stored at 15°C during shelf life (3 days), with populations of L. monocytogenes, pathogenic Y. enterocolitica, and E. coli O157:H7 gfp+ increasing from less than 2.0 log CFU/g on day 0 to 7.0, 4.0, and 5.6 log CFU/g, respectively. However, when mixed-ingredient salad was stored at 8°C during shelf life, only L. monocytogenes increased significantly, reaching 3.0 log CFU/g within 3 days. In plain baby spinach, only pathogenic Y. enterocolitica populations increased significantly during storage for 7 days, and this was exclusively at an abuse temperature (15°C). Thus, mixing ready-to-eat leafy vegetables with chicken meat strongly influenced levels of inoculated strains during storage. To explore the food safety implications of these findings, bacterial numbers were translated into risks of infection by modeling. The risk of listeriosis (measured as probability of infection) was 16 times higher when consuming a mixed-ingredient salad stored at 8°C at the end of shelf life, or 200,000 times higher when stored at 15°C, compared with when consuming it on the day of inoculation. This indicates that efforts should focus on preventing temperature abuse during storage to mitigate the risk of listeriosis. The storage conditions recommended for mixed-ingredient salads in Sweden (maximum 8°C for 3 days) did not prevent growth of L. monocytogenes in baby spinach mixed with chicken meat. Manufacturers preparing these salads should be aware of this, and recommended storage temperature should be revised downwards to reduce the risk of foodborne disease.

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