Inactivation of Listeria monocytogenes Scott A on Artificially Contaminated Frankfurters by High-Pressure Processing

2000 ◽  
Vol 63 (5) ◽  
pp. 662-664 ◽  
Author(s):  
L. A. LUCORE ◽  
T. H. SHELLHAMMER ◽  
A. E. YOUSEF
Keyword(s):  
High Pressure ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Bacterial Population ◽  
Brain Heart Infusion ◽  
High Pressure Processing ◽  
Brain Heart Infusion Agar ◽  
Log Reduction ◽  
Viable Method ◽  
Infusion Agar

Vacuum-packaged frankfurters, inoculated with 24-h cultures of Listeria monocytogenes Scott A (∼109 CFU/ml) by injection into the packages, were held at pressures of 300, 500, and 700 MPa for up to 9 min. L. monocytogenes were washed from the surface of the frankfurter and plated onto brain heart infusion agar. During the time to achieve 300, 500, and 700 MPa (come-up time), L. monocytogenes populations decreased by 1, >3, and >5 logs, respectively. Additional inactivation of L. monocytogenes occurred while the samples were held at 300 and 500 MPa. A 5-log reduction in bacterial population was possible at all pressure treatments; however, pressurization at 700 MPa showed the fastest inactivation with L. monocytogenes reduced from 108 to 102 CFU/package during the come-up time. These results show that high-pressure processing may be a viable method for controlling foodborne pathogens in postprocessed, packaged frankfurters.

High pressure processing of apple juice: the most effective parameters to inactivate pathogens of reference

2020 ◽  
Vol 122 (12) ◽  
pp. 3969-3979 ◽  
Author(s):  
Rodrigo Rodrigues Petrus ◽  
John Joseph Churey ◽  
Randy William Worobo
Keyword(s):  
High Pressure ◽  
Foodborne Pathogens ◽  
Apple Juice ◽  
High Pressure Processing ◽  
Effective Parameters ◽  
Content Type ◽  
E Coli ◽  
Log Reduction ◽  
Save Energy ◽  
Practical Implications

PurposeHigh-acid liquid foods are a substrate in which foodborne pathogens can maintain their viability. In this research an experimental design was conducted to optimize the parameters for high pressure processing (HPP) of apple juice (pH 3.76).Design/methodology/approachJuice was inoculated with cocktails of Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. Pressures ranging from 139 to 561 MPa and dwell times between 39 and 181 s were challenged.FindingsPressures above 400 MPa achieved a greater than 5-log reduction in all pathogen cocktails regardless of the dwell time. L. monocytogenes was more sensitive to HPP at a pressure of 350 MPa and dwell times equal to or beyond 110 s. E. coli O157:H7 and S. enterica exhibited similar resistance; the number of log reductions in the central point (350 MPa/110 s) ranged from 2.2 to 3.7. The first-order mathematical model better fitted experimental data for E. coli O157:H7 and S. enterica. In regard to L. monocytogenes, the second-order model better fitted this pathogen's reduction.Practical implicationsFruit juices are usually high pressure processed at approximately 600 MPa. For pathogenic reduction, the use of milder parameters may save energy and maintenance costs. The results herein exhibited could assist the apple juice industry with more effective applications of HPP.Originality/valueThe findings of this study demonstrate that relatively moderate pressures can be successfully used to assure the safety of apple juice.

Inactivation of Listeria monocytogenes Scott A 49594 in Apple Juice Supplemented with Cinnamon

2002 ◽  
Vol 65 (10) ◽  
pp. 1663-1666 ◽  
Author(s):  
J. YUSTE ◽  
D. Y. C. FUNG
Keyword(s):  
Listeria Monocytogenes ◽  
Apple Juice ◽  
Brain Heart Infusion ◽  
Killing Effect ◽  
Brain Heart Infusion Agar ◽  
Agar Layer ◽  
Infusion Agar ◽  
Enrichment Step

Normal (pH 3.7) and adjusted (pH 5.0) pasteurized apple juice containing cinnamon (0, 0.1, 0.2, and 0.3%) was inoculated with Listeria monocytogenes Scott A 49594 at 104 CFU/ml and stored at 5 and 20°C for 7 days. Counts on tryptic soy agar (TSA), modified Oxford (MOX) medium, and thin agar layer (TAL) were determined at 1 h and 1, 3, and 7 days. The TAL method (MOX medium overlaid with TSA) was used for the recovery of injured cells. In apple juice, both at normal and adjusted pH, with any doses of cinnamon, no L. monocytogenes (a 4.6-log CFU/ml reduction) was detected after 1 h of storage at both temperatures, and no growth occurred at any points of storage. Therefore, cinnamon by itself (regardless of pH) had a pronounced killing effect. A further enrichment step with brain heart infusion agar showed that L. monocytogenes was completely inactivated in apple juice stored at 20°C, except in pH 5.0 samples with 0.1% of cinnamon. The TAL method was as effective as TSA in recovering injured cells of L. monocytogenes. Cinnamon considerably inactivates L. monocytogenes in apple juice and thus enhances the safety of this product.

Inactivation Kinetics and Virulence Potential of Salmonella Typhimurium and Listeria monocytogenes Treated by Combined High Pressure and Nisin

2010 ◽  
Vol 73 (12) ◽  
pp. 2203-2210 ◽  
Author(s):  
JINGYU GOU ◽  
HYEON-YONG LEE ◽  
JUHEE AHN
Keyword(s):  
High Pressure ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Pressure Change ◽  
Weibull Model ◽  
B Value ◽  
High Pressure Processing ◽  
Inactivation Kinetics ◽  
Molecular Characteristics

The aim of this study was to characterize the physiological and molecular changes of Salmonella Typhimurium and Listeria monocytogenes in deionized water (DIW) and nisin solutions (100 IU/g) during high pressure processing (HPP). Strains of Salmonella Typhimurium and L. monocytogenes in DIW or nisin solutions were subjected to 200, 300, and 400 MPa for 20 min. The Weibull model adequately described the HPP inactivation of Salmonella Typhimurium and L. monocytogenes. Salmonella Typhimurium and L. monocytogenes populations were reduced to less than 1 CFU/ml in DIW and nisin solutions under 400 MPa. The highest b value was 5.75 for Salmonella Typhimurium in nisin solution under 400 MPa. L. monocytogenes was more sensitive to pressure change when suspended in DIW than when suspended in nisin. The pressure sensitivity of both Salmonella Typhimurium and L. monocytogenes was higher in DIW solution (141 to 243 MPa) than in nisin solution (608 to 872 MPa). No recovery of HPP-injured cells in DIW and nisin solutions treated at 400 MPa was observed after 7 days of refrigerated storage. The heterogeneity of HPP-treated cells was revealed in flow cytometry dot plots. The transcripts of stn, invA, prfA, and inlA were relatively down-regulated in HPP-treated nisin solution. The combination of high pressure and nisin could noticeably suppress the expression of virulence-associated genes. These results provide useful information for understanding the physiological and molecular characteristics of foodborne pathogens under high-pressure stress.

Effect of Cheese Water Activity and Carbohydrate Content on the Barotolerance of Listeria monocytogenes Scott A

2006 ◽  
Vol 69 (6) ◽  
pp. 1328-1333 ◽  
Author(s):  
PILAR MORALES ◽  
JAVIER CALZADA ◽  
BUENAVENTURA RODRÍGUEZ ◽  
MÁXIMO de PAZ ◽  
PILAR GAYA ◽  
...  
Keyword(s):  
High Pressure ◽  
Listeria Monocytogenes ◽  
Water Activity ◽  
Dry Matter ◽  
High Pressure Processing ◽  
Carbohydrate Content ◽  
Pressure Treatment ◽  
High Pressure Treatment ◽  
Log Reduction ◽  
Fresh Cheese

High-pressure processing is an appropriate technique for improving the microbiological safety of packaged ready-to-eat foods. The effect of high-pressure treatment on Listeria monocytogenes Scott A inoculated into fresh Hispánico-type cheese and ripe Mahón cheese was investigated. A 3.8-log reduction in the counts of L. monocytogenes Scott A in fresh cheese was recorded after 3 min at 400 MPa and 12°C, whereas 18 min under the same conditions was required to obtain a 1-log reduction in ripe cheese. Dry matter values were 48.96% for fresh cheese and 58.79% for ripe cheese, and water activity (aw) values were 0.983 and 0.922, respectively. In dehydrated fresh cheese (58.20% dry matter) in which 5% NaCl was added to achieve a 0.904 aw value, L. monocytogenes Scott A counts were lowered by only 0.4 log after treatment for 10 min at 400 MPa. On the other hand, in a 60:40 mixture of ripe cheese:distilled water with a 0.976 aw value, the reduction under the same conditions was 3.9 log. Within the aw range of 0.945 to 0.965, L. monocytogenes Scott A barotolerance was significantly higher in fresh cheese than in ripe cheese for equivalent aw values. Carbohydrate content was higher in fresh cheese than in ripe cheese. The addition of lactose at a concentration of 5 mg/g to an 85:15 mixture of ripe cheese:distilled water did not influence L. monocytogenes Scott A barotolerance during treatment for 10 min at 400 MPa. Galactose at a concentration of 5 mg/g had a protective effect during high-pressure treatment, and glucose at a concentration of 5 mg/g favored L. monocytogenes Scott A survival during refrigerated storage of pressurized samples at 8°C for 5 days.

scholarly journals Antimicrobial Activity of Oregano Essential Oil Incorporated in Sodium Alginate Edible Films: Control of Listeria monocytogenes and Spoilage in Ham Slices Treated with High Pressure Processing

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3726 ◽  
Author(s):  
Foteini Pavli ◽  
Anthoula A. Argyri ◽  
Panagiotis Skandamis ◽  
George-John Nychas ◽  
Chrysoula Tassou ◽  
...  
Keyword(s):  
High Pressure ◽  
Listeria Monocytogenes ◽  
Essential Oil ◽  
Storage Period ◽  
Edible Films ◽  
High Pressure Processing ◽  
Oregano Essential Oil ◽  
Log Reduction ◽  
Combined Application ◽  
Sensory Analyses

The aim of the study was to evaluate the efficacy of oregano essential oil (OEO) incorporated in Na-alginate edible films when applied to sliced ham inoculated with a cocktail of Listeria monocytogenes strains, with or without pretreatment by high pressure processing (HPP). Microbiological, physicochemical and sensory analyses (in Listeria-free slices) were performed, while, the presence/absence and the relative abundance of each Listeria strain, was monitored by pulsed field gel electrophoresis (PFGE). The OEO incorporation in the films, caused approximately 1.5 log reduction in Listeria population at 8 and 12 °C at the end of the storage period, and almost 2.5 log reduction at 4 °C. The HPP treatment caused 1 log reduction to the initial Listeria population, while levels kept on decreasing throughout the storage for all the tested temperatures. The pH of the samples was higher in the cases where HPP was involved, and the samples were evaluated as less spoiled. Furthermore, the presence of OEO in the films resulted in color differences compared to the control samples, whilst the aroma of these samples was improved. In conclusion, the combined application of HPP and OEO edible films on the slices, led to a significant reduction or absence of the pathogen.

Searching for high pressure processing parameters for Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes reduction in Concord grape juice

2019 ◽  
Vol 122 (1) ◽  
pp. 170-180 ◽  
Author(s):  
Rodrigo Petrus ◽  
John Churey ◽  
Randy Worobo
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Grape Juice ◽  
Processing Parameters ◽  
High Pressure Processing ◽  
Content Type ◽  
Log Reduction ◽  
Concord Grape

Purpose High pressure processing (HPP) has been widely used for high-acid (pH<4.6) juices. The purpose of this study was to investigate optimal parameters aimed at achieving 5-log reduction of the pathogens of reference in Concord grape juice (pH 3.39). Design/methodology/approach Grape juice was inoculated with five strain cocktails of Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes. In total, 11 trials were carried out based on a Central Composite Rotational Design (CCRD). The pressure (P), ranging from 319 to 531 MPa, and dwell time (t), from 35 to 205 s, were tested. The performance of the combinations (P × t) was evaluated by pathogen challenge microbiological assays. Findings E. coli O157:H7 was more resistant to HPP than S. enterica. L. monocytogenes did not grow in unprocessed juice (before HPP). Findings demonstrated that moderate pressures (~400 MPa) and short dwell times (~2 min) were effective in achieving a greater than 5-log reduction in the pathogens of reference. Practical implications Because the maintenance costs of equipment exponentially increase with pressure beyond 600 MPa, significant reductions in process pressure are highly desirable. Originality/value The results of this study can supplement the dearth of information on the applicability of high pressure as a Concord grape juice processing technology in terms of the pathogens inactivation. Furthermore, the use of a cocktail of five strains of pathogens inoculated in Concord grape juice to challenge different HPP parameters has not been reported.

Inactivation of Bacterial Pathogens in Human Milk by High-Pressure Processing†

2008 ◽  
Vol 71 (1) ◽  
pp. 109-118 ◽  
Author(s):  
S. VIAZIS ◽  
B. E. FARKAS ◽  
L. A. JAYKUS
Keyword(s):  
High Pressure ◽  
Human Milk ◽  
Capillary Tube ◽  
Bacterial Pathogens ◽  
High Pressure Processing ◽  
Viral Pathogens ◽  
Promising Alternative ◽  
Log Reduction ◽  
Long Time ◽  
Thermal Pasteurization

Low-temperature, long-time (LTLT) pasteurization assures the safety of banked human milk; however, heat can destroy important nutritional biomolecules. High-pressure processing (HPP) shows promise as an alternative for pasteurization of breast milk. The purpose of this study was to investigate the efficacy of HPP for inactivation of selected bacterial pathogens in human milk. Human milk was inoculated with one of five pathogens (108 to 109 CFU/ml), while 0.1% peptone solution solutions with the same levels of each organism were used as controls. The samples were subjected to 400 MPa at 21 to 31°C for 0 to 50 min or to 62.5°C for 0 to 30 min (capillary tube method) to simulate LTLT pasteurization. Tryptic soy agar and selective media were used for enumeration. Traditional thermal pasteurization resulted in inactivation (&gt;7 log) of all pathogens within 10 min. In human milk and in peptone solution, a 6-log reduction was achieved after 30 min of HPP for Staphylococcus aureus ATCC 6538. After 30 min, S. aureus ATCC 25923 was reduced by 8 log and 6 log in human milk and peptone solution, respectively. Treatments of 4 and 7 min resulted in an 8-log inactivation of Streptococcus agalactiae ATCC 12927 in human milk and peptone solution, respectively, while Listeria monocytogenes ATCC 19115 required 2 min for an 8-log inactivation in human milk. Escherichia coli ATCC 25922 was inactivated by 8 log after 10 min in peptone solution and by 6 log after 30 min in human milk. These data suggest that HPP may be a promising alternative for pasteurization of human milk. Further research should evaluate the efficacy of HPP in the inactivation of relevant viral pathogens.

scholarly journals Population-Wide Survey of Salmonella enterica Response to High-Pressure Processing Reveals a Diversity of Responses and Tolerance Mechanisms

2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Sandeep Tamber
Keyword(s):  
High Pressure ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
High Pressure Processing ◽  
Food Preservation ◽  
Iodide Uptake ◽  
Membrane Fatty Acid Composition ◽  
Content Type ◽  
Pressure Resistance ◽  
Treatment Sensitivity

ABSTRACTHigh-pressure processing is a nonthermal method of food preservation that uses pressure to inactivate microorganisms. To ensure the effective validation of process parameters, it is important that the design of challenge protocols consider the potential for resistance in a particular species. Herein, the responses of 99 diverseSalmonella entericastrains to high pressure are reported. Members of this population belonged to 24 serovars and were isolated from various Canadian sources over a period of 26 years. When cells were exposed to 600 MPa for 3 min, the average reduction in cell numbers for this population was 5.6 log10CFU/ml, with a range of 0.9 log10CFU/ml to 6 log10CFU/ml. Eleven strains, from 5 serovars, with variable levels of pressure resistance were selected for further study. The membrane characteristics (propidium iodide uptake during and after pressure treatment, sensitivity to membrane-active agents, and membrane fatty acid composition) and responses to stressors (heat, nutrient deprivation, desiccation, and acid) for this panel suggested potential roles for the cell membrane and the RpoS regulon in mediating pressure resistance inS. enterica. The data indicate heterogeneous and multifactorial responses to high pressure that cannot be predicted for individualS. entericastrains.IMPORTANCEThe responses of foodborne pathogens to increasingly popular minimal food decontamination methods are not understood and therefore are difficult to predict. This report shows that the responses ofSalmonella entericastrains to high-pressure processing are diverse. The magnitude of inactivation does not depend on how closely related the strains are or where they were isolated. Moreover, strains that are resistant to high pressure do not behave similarly to other stresses, suggesting that more than one mechanism might be responsible for resistance to high pressure and the mechanisms used may vary from one strain to another.

Sign in / Sign up

Export Citation Format

Share Document