Inoculated Listeria Monocytogenes Research Articles

Impact of sodium alginate-based film loaded with resveratrol and thymol on the shelf life of cooked sausage and the inoculated Listeria monocytogenes.

In present study, sodium alginate biodegradable films containing different concentrations of resveratrol (RES: 0.002% and 0.004%) or thymol (THY: 0.5% and 1%) and their combinations were prepared, and evaluated for their effects on spoilage-related microbial profile, lipid oxidation, sensory properties, and protective effects against Listeria monocytogenes in beef mortadella sausage during 40 days storage at 4°C. The release rate of phenolic compounds was determined by the Folin-Ciocalteu test. To assess the shelf life of the product, changes in total viable count (TVC), lactic acid bacteria count (LAB), psychrotrophic bacteria count (PTC), pH levels, thiobarbituric acid reactive substances (TBARS) levels, and sensory characteristics (taste, color, odor, and overall acceptability) were evaluated. For the sensory evaluation, a panel of 70 semi-trained judges was selected according to their initial performance. Samples wrapped with sodium alginate films containing 1% THY (alone or combined with different concentrations of RES) exhibited lower bacterial counts compared to other experimental groups at the end of the storage period (6.01-6.35 vs. 6.71-8.17 log10 CFU/g for TVC, 5.37-5.83 vs. 6.07-7.11 log10 CFU/g for LAB, 5.08-5.18 vs. 5.40-7.23 log10 CFU/g for PTC, and 6.53-6.92 vs. 7.23-9.01 log10 CFU/g for inoculated L. monocytogenes). Sodium alginate films containing the combination of 0.004% RES and different concentrations of THY showed higher antioxidant effects than other experimental groups (TBARS values of 1.68-1.99 vs. 2.23-3.80 mg MDA/kg sample). The sodium alginate film containing 0.004% RES + 1% THY exhibited the highest antimicrobial and antioxidant activities and highest sensory scores among all treatments. These findings highlight the potential application of the sodium alginate film containing a combination of RES and THY as an active packaging material with natural preservatives in the meat products industry. This application can effectively extend the shelf life and enhance the microbial safety of clean-label cooked sausages during refrigerated storage.

Impact of Sodium Alginate-Based Film Loaded With Resveratrol and Thymol on the Shelf Life of Cooked Sausage and the Inoculated Listeria Monocytogenes

Impact of Sodium Alginate-Based Film Loaded With Resveratrol and Thymol on the Shelf Life of Cooked Sausage and the Inoculated Listeria Monocytogenes

High pressure processing at the early stages of ripening enhances the safety and quality of dry fermented sausages elaborated with or without starter culture

To study the quality of chorizo de León dry fermented sausages (DFS), high pressure processing (HPP) applied at the early stages of ripening and the use of a functional starter culture were evaluated as additional safety measures. Furthermore, the ability to control the populations of artificially inoculated Listeria monocytogenes and Salmonella Typhimurium was investigated and the evolution of microbial communities was assessed by amplicon 16S rRNA metataxonomics. The use of HPP and the starter culture, independently or combined, induced a reduction of Listeria monocytogenes of 1.5, 4.3 and > 4.8 log CFU/g respectively, as compared to control. Salmonella Typhimurium counts were under the detection limit (<1 log) in all treated end-product samples. Both additional measures reduced the activity of undesirable microbiota, such as Serratia and Brochothrix, during the production of DFS. Moreover, the starter culture highly influencedthe taxonomic profile of samples.No adverse sensory effects were observed, and panelists showed preference for HPP treated DFS. In conclusion, this new approach of applying HPP at the early stages of ripening of DFS in combination with the use of a defined starter culture improved the safety and quality of the meat product.

Applying gelatine:chitosan film loaded with nanoemulsified garlic essential oil/α‐tocopherol as active packaging of sliced Omega‐3‐rich mortadella

SummaryThe effect of using gelatine:chitosan (G:Ch) based films as carriers of nanoemulsified garlic essential oil/α‐tocopherol (0.4% v/v) on the shelf‐life and sensory acceptance of sliced omega‐3‐rich mortadella stored at 6 ± 1 °C for 7 days, was investigated. Three treatments were evaluated: mortadella packed with active (T1) and passive films (T2) and without (T3) films. T1 presented the highest effectiveness against the inoculated Listeria monocytogenes and Pseudomonas aeruginosa and retarded spoilage bacteria growth. The colour coordinates, pH and Aw of T1 were affected by the active film. TBARs values from T2 and T3 overcame the threshold of 1.0 mg MDA kg−1 sample at day 5. Panellists scored all sensory attributes between 6 (slightly liked) and 7 (moderately liked) within all treatments. The active G:Ch films developed has the potential to be used as good preservative carrier in sliced mortadella during refrigerated storage, and thus, this product can be processed without synthetic preservative.

Characterization of novel probiotic nanocomposite films based on nano chitosan/ nano cellulose/ gelatin for the preservation of fresh chicken fillets

In this study, nano cellulose-nano chitosan-gelatin films containing Lactobacillus casei (L. casei) and Bacillus coagulans (B. coagulans) GBI-30, 6086, and a combination of them were produced. The refrigerated fillets were examined for inoculated Listeria monocytogenes (1 × 105 cfu/g), microbial and chemical properties for 14 days. According to the results, with the addition of probiotic bacteria to the nanocomposite films (NF), elongation-to-break and tensile strength decreased significantly; significantly (P < 0.05) increased were observed in the thickness and brightness of the films, and no significant effect (P > 0.05) was observed about moisture and solubility. There was a significant negative association between probiotic survival and storage period, with B. coagulans (6.35 log CFU/g) having a greater survival rate than L. casei (6.01 log CFU/g) (P < 0.05). The analysis of fillets indicated that probiotic film slowed down the increasing trend of oxidative and microbial spoilage indices compared to the control group (P < 0.05). The best results were observed at the end of the storage time in NF + L. casei + B. coagulans. Therefore, it seems that NF probiotics can improve the quality and shelf life of chicken fillets during the refrigerated storage which could be a method of using probiotics in chicken fillets.

Quality and safety aspects in fermentation of winged kelp (Alaria esculenta) and sugar kelp (Saccharina latissima) by the natural microbiota with or without addition of a Lactiplantibacillus plantarum starter culture

Nourishment of the growing human population requires new and alternative food sources, preferable produced without occupying new land areas. Cultivation of seaweed presents an opportunity, however, a major obstacle is sustainable preservation. Fermentation has been used for centuries to preserve vegetables, e.g., to produce kimchi based on cabbage. This study investigated changes in the microbiota, characteristics (pH, organic acids and water soluble carbohydrates) and food safety of raw shredded Alaria esculenta and Saccharina latissima during fermentation by the natural microbiota with or without addition of a Lactiplantibacillus plantarum starter culture. The Lb. plantarum fermented products retained a high Shannon diversity index, indicating a partially unsuccessful fermentation. Lb. plantarum performed better in A. esculenta causing pH to drop to below 4.6, a critical limit for control of growth of Clostridium botulinum, within 2 days compared to 7 days for S. latissima. Natural fermentation by the endogenous microbiota resulted in unsafe products with high final pH values (4.8–5.2), presence of unwanted organic acids, such as butyric acid, and in the case of A. esculenta sustenance of inoculated Listeria monocytogenes. Fermentation of A. esculenta and S. latissima by Lb. plantarum is a promising preservation method. However, future work is needed to optimise the process, by investigation of the use of different starter cultures, seaweed pre-treatments (blanching, freezing, etc.) and adjuvants (i.e., addition of sugars, minerals and similar) to promote growth of the starter culture and ensure the fermented products are safe to eat.

Alginate Coating and Electrolyzed Oxidizing Water: Their Antimicrobial Effects against Inoculated Listeria Monocytogenes on Salmon Fillets

Introduction: This study was conducted to evaluate to investigate the inhibitory effect of alginate coating and EOW on listeria monocytogenes in fish samples during 12 days in cold storage condition (at 4˚c). Methods: First, fish fillets were inoculated with listeria monocytogenes, and they were divided into different groups. Then, treated samples including control (no coating), distilled water, alginate, EOW, alginate coating along with EOW were stored at refrigeration temperature. The fillets were kept at 4° C, and the bacterial count was performed on days: 0, 2, 4, 8, and 12. Results: Both individual and combined use of alginate and electrolyzedoxidizing water can significantly inhibit the growth of listeria monocytogenes inoculated compared to control samples, so that the maximum reduction in EOW & alginate treatment (1.37 log CFU / g) was observed. Conclusion: According to the obtained results, it is recommended to use alginate coating along with electrolysis water in fish to improve safety against listeria monocytogenes.

Impact of gelatin nanogel coating containing thymol and nisin on the microbial quality of rainbow trout fillets and the inoculated Listeria monocytogenes

This study aimed to assess the effects of edible gelatin nanogel coating containing thymol and nisin on the inhibition of microbial flora and inoculated Listeria monocytogenes in fish fillets during a 12-day storage period at the temperature of 4°C. Data were collected and analysed on several factors of microbiological change, including total viable count, total psychrophilic count, lactic acid bacteria and hydrogen sulphide-producing bacteria count, and the inhibitory effects of the coating on inoculated Listeria monocytogenes were determined during 3-day intervals. The highest reduction rate of total viable bacteria (0.95 log CFU/g), total psychrophilic (0.92 log CFU/g), Hydrogen sulfide producing bacteria (0.66 log CFU/g), lactic acid bacteria (0.95 log CFU/g) and L. monocytogenes count (0.65 log CFU/g) were observed in gelatin nanogel containing thymol and nisin in comparison with control samples. Furthermore, the separate use of these compounds led to the significant growth inhibition of the bacteria compared with the control. Therefore, it was concluded that the gelatin nanogel coating without an antimicrobial agent could not be effective in bacterial growth control, and the added thymol and nisin would be beneficial in the preservation of foods such as fish and its products.

Inhibition of Listeria monocytogenes growth in turkey fillets by alginate edible coating with Trachyspermum ammi essential oil nano-emulsion

The objective of this study was to determine the chemical composition and antibacterial activity of Trachyspermum ammi essential oil (TAEO). Moreover, the present study comparatively investigated TAEO in the forms of emulsion and Nano-emulsion in alginate-based edible coatings against inoculated Listeria monocytogenes in turkey fillets during 12 days in cold storage (at a temperature of 4 ± 1 °C). Alginate solutions with two levels of TAEO (in emulsion and Nano-emulsion forms) were prepared in this study. The bacterial count was performed on days 0, 1, 2, 4, 8, and 12. Based on the obtained results of the current study, a comparison of different treatments with the blank samples (without any coating) showed that the highest considerable result was observed in the samples with Nano-emulsion coating (P < 0.05). Nano-emulsion loaded alginate coating prevented the growth of listeria in turkey fillets even after 12 days of cold storage. According to the findings of this study, the application of alginate edible coatings containing TAEO, especially in Nano-form, can be very effective in controlling the growth of L. monocytogenes, as a foodborne pathogen, during storage; therefore, it is a good choice to be applied in the meat industry.

High‐pressure treatment of silver pomfret ( Pampus argenteus ): Inactivation of Listeria monocytogenes , impact on amino acid profile, and changes during storage in fatty acid compositions

The objective of this work was to optimize a suitable high-pressure (HP) condition to inactivate artificially inoculated Listeria monocytogenes in silver pomfret (Pampus argenteus) fish medium by employing a wide range of pressure levels (225–550 MPa) and holding times (5–30 min). The optimized HP conditions (375 MPa/20 min) were subsequently employed in pomfret fish. Glycine and glutamic acid were the predominant amino acids in pomfret fish. The HP treatment increased the total amino acids from 5.89 to 6.92 mmol/g (p < .05), while there was no significant change in the free amino acids. The change in the fatty acid profiles of silver pomfret fillet processed after high-pressure (HP) treatment was assessed over 30 days at 4°C and 60 days at −20°C storage. The HP treatment did not influence the fatty acid profiles; however, the storage significantly influenced both saturated and polyunsaturated fatty acids (p < .05). Practical applications The application of high-pressure treatment has been successfully employed to various fish species. However, the intensity of pressure and the holding time varied widely among species and the nutrient profile. Therefore, each fish needs special attention. Applying 375 MPa for 20 min to the silver pomfret fillets resulted in complete inactivation of the pathogen with insignificant changes in the quality and fatty acid profiles. The index of coronary heart disease, namely, atherogenicity index and thrombogenicity index, changed insignificantly after the pressurization. Storage of pressure-treated fillets decreases the PUFA content significantly. These results could promote applications of pressurized pomfret fillets in the fish industry.

Effect of corn starch coating incorporated with nanoemulsion of Zataria multiflora essential oil fortified with cinnamaldehyde on microbial quality of fresh chicken meat and fate of inoculated Listeria monocytogenes.

The present study compared the effects of corn starch coatings incorporated with Zataria multiflora essential oil (ZEO) and cinnamaldehyde (CIN) in conventional, nanoemulsion (NZEO) and fortified nanoemulsion (NZEOC) forms, on specific spoilage microorganisms of chicken meat and on the fate of inoculated Listeria monocytogenes during 20days storage at 4 ± 1°C. Based on the results of GC-MS analysis of ZEO, carvacrol (36.62%) was the most important compound of essential oil. Samples coated with the starch solution containing nanoemulsions had better antimicrobial activities than conventional forms. Also, NZEOC treatment had the best antimicrobial properties at the end of storage with the following results: Total viable count (7.96 log10 CFU/g), Psychrotrophic count (7.29 log10 CFU/g), Lactic acid bacteria (6.51 log10 CFU/g), Enterobacteriaceae count (6.98 log10 CFU/g), Mold and yeast count (5.16 log10 CFU/g) and inoculated L. monocytogenes (6.51 log10 CFU/g). Furthermore, the addition of CIN-ZEO during nanoemulsion formation (NZEOC) increased the antimicrobial properties of the samples compared to individual addition of NZEO and CIN (NZEO + CIN) to the starch solution. Therefore, corn starch coating containing NZEOC is recommended as a natural preservative to enhance the microbial stability of poultry meat.

Treatment of beef with gaseous ozone: Physicochemical aspects and antimicrobial effects on heterotrophic microflora and listeria monocytogenes

The treatment of beef with gaseous ozone (GO) was analyzed and the physicochemical characteristics (texture, lipid oxidation, surface color) and food safety (microbial growth of heterotrophic microflora and inoculated Listeria monocytogenes) were evaluated.Transient changes in ozone concentration within the chamber were mathematically modeled using a non-stationary mass balance. Ozone pulses were applied and treatment intensities were evaluated in each case. GO treatment prolonged refrigerated storage of vacuum packed beef. Long periods of exposure to ozone (>10 min) negatively affected the red color and oxidative rancidity. The most effective treatments to control microbial flora were ozone pulses ranging between 5 and 10 min duration every 30 min for 5 h using 280 mg O3 m−3; these treatments allowed the reduction of more than 1 logarithmic cycle the counts of the natural flora in beef (lactic acid bacteria, mesophilic and enterobacteriaceae), maintaining oxidative stability and adequate physicochemical parameters. Additionally these low doses of GO decreased the counts of inoculated L. monocytogenes (102 CFU g tissue−1) to values below the detection limit for 16 days at 4 °C limiting its growth during refrigerated storage. The use of GO in beef products allows the control of microbial growth during refrigerated storage maintaining high quality parameters.

High-pressure processing and storage temperature on Listeria monocytogenes, microbial counts and oxidative changes of two traditional dry-cured meat products

The effects of high hydrostatic pressure (HHP) processing (600 MPa, 8 min, 16 °C) and storage temperature (4 °C and 18 °C) on experimentally inoculated Listeria monocytogenes (L. monocytogenes), mesophilic aerobic plate counts (APC) and yeast and mould (YM) populations in Iberian dry-cured “salchichón” (DCS) and dry-cured loin (DCL) during 120 days of storage were studied. Tocopherol contents, fatty acid profile, instrumental colour and lipid and protein oxidation were evaluated. HHP treatment reduced L. monocytogenes population by >3 log10 in both DCS and DCL. HHP and storage temperature affected APC differently in both products, whereas YM were significantly decreased by HHP, mostly at 18 °C. Lipid and protein oxidation were promoted, mainly in DCS, and the colour was affected in a minor extent. Despite these effects on oxidation, these results suggest that HHP treatment at 600 MPa for 8 min in both products allowed to control L. monocytogenes below the microbiological limit established by the food safety regulations.

Antimicrobial kinetics of nisin and grape seed extract against inoculated Listeria monocytogenes on cooked shrimps: Survival and residual effects

The antimicrobial effects of nisin (2000 IU/mL) and grape seed extract (GSE, 1%) against Listeria monocytogenes (SSA184, SSA97 and LM10) inoculated on cooked shrimps (Litopenaeus vannamei) were investigated. Notable reductions (1.7–1.9 log CFU/g reduction) of L. monocytogenes were observed after 15-min treatment of combined nisin and GSE while SSA184 showed the highest susceptibility to the activity of nisin and GSE as compared to other strains. The atomic force microscopy results indicated that greater morphological changes were found in combination treated cells of SSA184, whose width (0.47 μm) and height (0.25 μm) were decreased while the surface roughness (10.12 nm) was increased significantly (P < 0.05). Residual nisin and GSE further inhibited the listerial growth during storage (0.4–0.8 log CFU/g increment). Based on the fitting goodness, Weibull and Baranyi models were verified as the best ones to describe inactivation kinetics of L. monocytogenes and growth dynamics during storage, respectively. Additionally, the colour of cooked shrimpsafter combined treatment were not negatively affected and even protected during storage. In conclusion, the antimicrobial treatment of combined nisin and GSE could be a potential antilisterial strategy for shrimps.

Effect of Eryngium caeruleum essential oil on microbial and sensory quality of minced fish and fate of Listeria monocytogenes during the storage at 4°C

AbstractThe present study investigated in vitro antimicrobial activity of Eryngium caeruleum essential oil (EEO) against five foodborne pathogenic bacteria based on microdilution and disk diffusion methods. Moreover, its effects on specific spoilage microorganisms, inoculated Listeria monocytogenes, and its sensory changes in minced fish were evaluated during 12 days of storage at refrigeration temperature. The results showed that Staphylococcus aureus and Escherichia coli were the most sensitive and the most resistant bacteria with a minimum inhibitory concentration of 0.125 and 1 mg/ml, as well as inhibition zones of 15.66 and 11.66 mm, respectively. Regarding the antimicrobial effect of EEO on the microbial profile and inoculated L. monocytogenes, treating with 0.4% EEO caused a significant decrease in the studied microorganisms when compared to the control group (p &lt; 0.05). In addition, considering the sensory evaluation, the best scores were observed for the samples treated with 0.2% and 0.4% EEO. However, none of the groups obtained acceptable scores until the final day of storage except for the color attribute. In general, sensory evaluation and its correlation with microbial counting indicated that the treatment with 0.4% EEO was able to preserve the microbial quality of the minced fish at refrigeration temperature without any undesirable sensory effects.

Quality and Safety of Fresh Chicken Fillets after High Pressure Processing: Survival of Indigenous Brochothrix thermosphacta and Inoculated Listeria monocytogenes.

The effect of high-pressure processing (HPP) on Listeria monocytogenes, the indigenous microbiota and the shelf-life of chicken fillets was evaluated. Chicken fillets were inoculated with different inocula (2, 4, and 6 log CFU/g) of a 4-strain cocktail of L. monocytogenes, vacuum-packed, processed or not with HPP (500 MPa/10 min) and stored at 4 °C and 12 °C. Total viable counts (TVC), L. monocytogenes, Pseudomonas spp., Brochothrix thermosphacta, lactic acid bacteria (LAB), Enterobacteriaceae and yeasts/molds were determined along with the pH and sensory analysis. Pulsed-field gel electrophoresis (PFGE) was used to monitor the succession of indigenous Brochothrix isolates and inoculated Listeria strains. The main spoilage microorganism of HPP-treated samples was B. thermosphacta detected after 3 days of storage. HPP decreased the inoculated Listeria population. For the low and medium inoculum case it was detected throughout the shelf-life at both temperatures in populations near to the detection limit or after enrichment. In the high inoculum case, the pathogen decreased ≥5-log cycles after HPP, while increased subsequently to 1.6 and 4.5 log CFU/g at 4 °C and 12 °C, respectively, by the end of the shelf-life. PFGE showed that Brochothrix isolates exhibited a significant diversity among control samples, whereas this was limited for the HPP-treated samples. The survival and distribution of different Listeria strains depended on the initial inoculum and storage temperature. In conclusion, HPP increased the shelf-life (for 5 and 4 days, at 4 °C and 12 °C, respectively) and enhanced the safety of chicken meat.

Necroptosis mediators RIPK3 and MLKL suppress intracellular Listeria replication independently of host cell killing.

RIPK3, a key mediator of necroptosis, has been implicated in the host defense against viral infection primary in immune cells. However, gene expression analysis revealed that RIPK3 is abundantly expressed not only in immune organs but also in the gastrointestinal tract, particularly in the small intestine. We found that orally inoculated Listeria monocytogenes, a bacterial foodborne pathogen, efficiently spread and caused systemic infection in Ripk3-deficient mice while almost no dissemination was observed in wild-type mice. Listeria infection activated the RIPK3-MLKL pathway in cultured cells, which resulted in suppression of intracellular replication of Listeria Surprisingly, Listeria infection-induced phosphorylation of MLKL did not result in host cell killing. We found that MLKL directly binds to Listeria and inhibits their replication in the cytosol. Our findings have revealed a novel functional role of the RIPK3-MLKL pathway in nonimmune cell-derived host defense against Listeria invasion, which is mediated through cell death-independent mechanisms.

Fate of inoculated Listeria monocytogenes on yellow onions (Allium cepa) under conditions simulating food service and consumer handling and storage

Recalls and cases of listeriosis have been associated with the presence of Listeria monocytogenes in fresh-cut refrigerated or frozen onions or associated processing environments. The survival or growth of L. monocytogenes on the outer surface of whole onions and in diced onion was evaluated during simulated retail or consumer storage. Whole and diced yellow onions (Allium cepa) were inoculated with a 6-strain cocktail of L. monocytogenes collected either from agar plates or from broth culture. Marked circles (3.3 cm in diameter) on the outer papery skin of whole onions were spot inoculated (10 μl) at 7 log CFU per circle, dried for 30 min and then stored at 4 or 23 °C for up to 8 weeks. The marked circles or “disks” of the outermost skin layer were excised for sampling. Diced onions were inoculated at 3 log CFU/g and then stored in closed containers at 4 or 10 °C for 28 or 21 days, respectively, or at 23 °C for 38 h. Populations of L. monocytogenes were determined by plating each sample onto both tryptic soy agar and modified Oxford or CHROMagar Listeria agars. At 4 °C, populations of L. monocytogenes on whole onion declined from initial pre-drying levels of 6–7 log CFU/disk to mean levels of 2.39 ± 1.14 log CFU/disk at week 8; at 23 °C, populations declined to below the limit of detection by plating (<0.40 log CFU/disk) and by enrichment in 3, 9, and 12 of 12 samples at weeks 2, 3, and 4, respectively. No significant change in L. monocytogenes populations was observed in diced onion during 28 days of storage at 4 °C. A maximum rate of change of 0.0081 log CFU/g/day; a mean L. monocytogenes population of 6.86 ± 0.44 log CFU/g was observed at 17 days of storage at 10 °C. At 23 °C calculated lag times of 4.7 and 8.6 h, maximum rates of change of 0.15 and 0.16 log CFU/g/h, and maximum L. monocytogenes populations of 6.24 ± 0.07 and 6.10 ± 0.03 log CFU/g after 38 h of storage were observed in diced onion inoculated with agar and broth cultures, respectively. Diced onions support the growth of L. monocytogenes at 10 and 23 °C but not at 4 °C.

Effects of High Pressure Processing and Hot Water Pasteurization of Cooked Sausages on Inactivation of Inoculated Listeria monocytogenes, Natural Populations of Lactic Acid Bacteria, Pseudomonas spp., and Coliforms and Their Recovery during Storage at 4 and 10°C

The study investigated the effects of high pressure processing (HPP; 600 MPa for 3 min) and hot water (HW; 75°C for 15 min) pasteurization on the inactivation of inoculated Listeria monocytogenes, natural populations of lactic acid bacteria, Pseudomonas spp., and coliforms in vacuum-packaged cooked sausages and their recovery during storage at 4 and 10°C for 35 days. Cooking sausages to an internal temperature of 72°C resulted in a >6-log reduction in numbers of inoculated L. monocytogenes. Storage at 4°C resulted in no significant difference ( P > 0.05) in L. monocytogenes numbers in sausages pasteurized by either HPP or HW compared with unpasteurized control. However, at 10°C, L. monocytogenes numbers in unpasteurized control sausages increased to about 7 log CFU/g by day 35, whereas in HPP-pasteurized sausages, numbers remained below the detection limit for up to 21 days and then increased to 4.5 log CFU/g by day 35. HW pasteurization resulted in inhibition of L monocytogenes to below the detection limit throughout the 35-day storage at 10°C. Natural lactic acid bacteria populations were significantly reduced by HPP and HW pasteurization and continued to be significantly lower at the end of the 35-day storage. Unlike most studies that focus on HPP or HW treatment of postcooking surface contamination of meat with Listeria, this study examined the combined effect of cooking, HPP, and HW on raw meat with a high contamination level. This scenario is important in countries where raw meat supply and in-store refrigeration are a challenge. The results suggest that HPP and HW pasteurization could be used to successfully enhance the safety and shelf life of cooked sausages and that HW pasteurization (75°C) was more effective than HPP (600 MPa) to control L. monocytogenes.

Effects of alginate coating incorporated with Bunium persicum essential oil and Lactoperoxidase system on inoculated Listeria monocytogenes in chicken breast fillets

Effects of alginate coating incorporated with Bunium persicum essential oil and Lactoperoxidase system on inoculated Listeria monocytogenes in chicken breast fillets