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.

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.

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.

scholarly journals Impact of Innovative Technologies on the Content of Vitamin C and Its Bioavailability from Processed Fruit and Vegetable Products

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Monika Mieszczakowska-Frąc ◽  
Karolina Celejewska ◽  
Witold Płocharski
Keyword(s):  
High Pressure ◽  
Vitamin C ◽  
Electric Fields ◽  
New Technologies ◽  
High Pressure Processing ◽  
Food Preservation ◽  
Fruit And Vegetable ◽  
Negative Effects ◽  
Minimal Processing ◽  
Processing Technologies

Nowadays, thermal treatments are used for extending the shelf-life of vegetable and fruit products by inactivating microorganisms and enzymes. On the other hand, heat treatments often induce undesirable changes in the quality of the final product, e.g., losses of nutrients, color alterations, changes in flavor, and smell. Therefore, the food industry is opening up to new technologies that are less aggressive than thermal treatment to avoid the negative effects of thermal pasteurization. Non-thermal processing technologies have been developed during the last decades as an alternative to thermal food preservation. Processing changes the structure of fruit and vegetables, and hence the bioavailability of the nutrients contained in them. In this review, special attention has been devoted to the effects of modern technologies of fruit and vegetable processing, such as minimal processing (MPFV), high-pressure processing (HPP), high-pressure homogenization (HPH), ultrasounds (US), pulsed electric fields (PEF), on the stability and bioavailability of vitamin C.

scholarly journals Unravelling the Molecular Mechanisms Underlying the Protective Effect of Lactate on the High-Pressure Resistance of Listeria monocytogenes

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 677
Author(s):  
Cristina Serra-Castelló ◽  
Ilario Ferrocino ◽  
Anna Jofré ◽  
Luca Cocolin ◽  
Sara Bover-Cid ◽  
...  
Keyword(s):  
High Pressure ◽  
Protective Effect ◽  
Molecular Mechanisms ◽  
Rna Extraction ◽  
Meat Products ◽  
High Pressure Processing ◽  
Membrane Properties ◽  
Short Exposure ◽  
Cooked Ham ◽  
Pressure Resistance

Formulations with lactate as an antimicrobial and high-pressure processing (HPP) as a lethal treatment are combined strategies used to control L. monocytogenes in cooked meat products. Previous studies have shown that when HPP is applied in products with lactate, the inactivation of L. monocytogenes is lower than that without lactate. The purpose of the present work was to identify the molecular mechanisms underlying the piezo-protection effect of lactate. Two L. monocytogenes strains (CTC1034 and EGDe) were independently inoculated in a cooked ham model medium without and with 2.8% potassium lactate. Samples were pressurized at 400 MPa for 10 min at 10 °C. Samples were subjected to RNA extraction, and a shotgun transcriptome sequencing was performed. The short exposure of L. monocytogenes cells to lactate through its inoculation in a cooked ham model with lactate 1h before HPP promoted a shift in the pathogen’s central metabolism, favoring the metabolism of propanediol and ethanolamine together with the synthesis of the B12 cofactor. Moreover, the results suggest an activated methyl cycle that would promote modifications in membrane properties resulting in an enhanced resistance of the pathogen to HPP. This study provides insights on the mechanisms developed by L. monocytogenes in response to lactate and/or HPP and sheds light on the understanding of the piezo-protective effect of lactate.

Impact of high pressure processing on microbiological, nutritional and sensory properties of food: a review

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ajith Amsasekar ◽  
Rahul S. Mor ◽  
Anand Kishore ◽  
Anupama Singh ◽  
Saurabh Sid
Keyword(s):  
High Pressure ◽  
Food Quality ◽  
High Pressure Processing ◽  
Microbial Inactivation ◽  
Sensory Properties ◽  
Process Conditions ◽  
Processed Food ◽  
Content Type ◽  
Food Properties ◽  
The Impact

Purpose The increased demand for high-quality, nutritionally rich processed food has led to non-thermal food processing technologies like high pressure processing (HPP), a novel process for microbial inactivation with minimal loss of nutritional and sensory properties. The purpose of this paper is to highlight the impact of HPP on the microbiological, nutritional and sensory properties of food. Design/methodology/approach Recent research on the role of HPP in maintaining food quality and safety and the impact of process conditions with respect to various food properties have been explored in this paper. Also, the hurdle approach and the effectiveness of HPP on food quality have been documented. Findings HPP has been verified for industrial application, fulfilling the consumer demand for processed food with minimum nutrition loss at low temperatures. The positive impact of HPP with other treatments is known as the hurdle approach that enhances its impact against microorganism activity and minimizes the effects on nutrition and sensory attributes. Originality/value This paper highlights the impact of HPP on various food properties and a good alternative as non-thermal technology for maintaining shelf life, sensory properties and retention of nutrients.

Inactivation of Yersinia pseudotuberculosis 197 and Francisella tularensis LVS in Beverages by High Pressure Processing

2009 ◽  
Vol 72 (1) ◽  
pp. 165-168 ◽  
Author(s):  
JOSEPH E. SCHLESSER ◽  
BRIAN PARISI
Keyword(s):  
High Pressure ◽  
Francisella Tularensis ◽  
Orange Juice ◽  
Yersinia Pseudotuberculosis ◽  
Hold Time ◽  
Skim Milk ◽  
High Pressure Processing ◽  
Pressure Treatment ◽  
Log Reduction ◽  
Pressure Resistance

In 2003, the U.S. Department of Health and Human Services announced a new research program to develop technologies and strategies to prevent and minimize potential food safety and security threats. The threat of terrorist attacks against the nation's food supplies has created the need to study microorganisms not typically associated with foodborne illness. High-pressure processing has been proposed as a treatment to reduce Yersinia pestis and Francisella tularensis LVS levels in beverages. The objectives of this work were to determine the pressure resistance of Y. pseudotuberculosis 197 (surrogate for Y. pestis) and F. tularensis LVS (vaccine strain). For each bacterium, samples of ultrahigh-temperature pasteurized skim milk and pasteurized reduced-acid orange juice (pH ca. 4.2) were inoculated at a minimum level of 5 log CFU/ml. Ten-milliliter samples of the inoculated product were vacuum sealed in polyester pouches and subjected to pressures of 300 and 500 MPa for holding times ranging from 30 s to 6 min. One set of trials was performed at an initial temperature of 10°C and another at 25°C. Processed samples were immediately plated and enumerated. A pressure treatment of 300 MPa at 25°C for less than 6 min was not sufficient to achieve a 5-log reduction of Y. pseudotuberculosis 197 or F. tularensis LVS in milk. However, a pressure treatment of 500 MPa was effective at hold times as low as 30 s. Overall, F. tularensis LVS demonstrated less pressure resistance than Y. pseudotuberculosis 197. Based on these findings, a high-pressure process designed to inactivate 5 log CFU of Y. pseudotuberculosis 197 per ml and F. tularensis LVS in orange juice or milk should be set at or above 500 MPa with a hold time of 2 min or greater.

scholarly journals Poultry Body Temperature Contributes to Invasion Control through Reduced Expression of Salmonella Pathogenicity Island 1 Genes in Salmonella enterica Serovars Typhimurium and Enteritidis

2015 ◽  
Vol 81 (23) ◽  
pp. 8192-8201 ◽  
Author(s):  
Bryan Troxell ◽  
Nicholas Petri ◽  
Caitlyn Daron ◽  
Rafaela Pereira ◽  
Mary Mendoza ◽  
...  
Keyword(s):  
Body Temperature ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Pathogenicity Island ◽  
Avian Host ◽  
Content Type ◽  
Poultry Products ◽  
Epithelial Cell Layer

ABSTRACTSalmonella entericaserovars Typhimurium (S. Typhimurium) and Enteritidis (S. Enteritidis) are foodborne pathogens, and outbreaks are often associated with poultry products. Chickens are typically asymptomatic when colonized by these serovars; however, the factors contributing to this observation are uncharacterized. Whereas symptomatic mammals have a body temperature between 37°C and 39°C, chickens have a body temperature of 41°C to 42°C. Here,in vivoexperiments using chicks demonstrated that numbers of viableS. Typhimurium orS. Enteritidis bacteria within the liver and spleen organ sites were ≥4 orders of magnitude lower than those within the ceca. When similar doses ofS. Typhimurium orS. Enteritidis were given to C3H/HeN mice, the ratio of the intestinal concentration to the liver/spleen concentration was 1:1. In the avian host, this suggested poor survival within these tissues or a reduced capacity to traverse the host epithelial layer and reach liver/spleen sites or both.Salmonellapathogenicity island 1 (SPI-1) promotes localization to liver/spleen tissues through invasion of the epithelial cell layer. Followingin vitrogrowth at 42°C, SPI-1 genessipC,invF, andhilAand the SPI-1rtsAactivator were downregulated compared to expression at 37°C. Overexpression of thehilAactivatorsfur,fliZ, andhilDwas capable of inducinghilA-lacZat 37°C but not at 42°C despite the presence of similar levels of protein at the two temperatures. In contrast, overexpression of eitherhilCorrtsAwas capable of inducinghilAandsipCat 42°C. These data indicate that physiological parameters of the poultry host, such as body temperature, have a role in modulating expression of virulence.

Effects of High Pressure, Subzero Temperature, and pH on Survival of Listeria monocytogenes in Buffer and Smoked Salmon

2008 ◽  
Vol 71 (8) ◽  
pp. 1612-1618 ◽  
Author(s):  
M. RITZ ◽  
F. JUGIAU ◽  
M. FEDERIGHI ◽  
N. CHAPLEAU ◽  
M. de LAMBALLERIE
Keyword(s):  
High Pressure ◽  
Listeria Monocytogenes ◽  
Differential Resistance ◽  
High Pressure Processing ◽  
Food Preservation ◽  
Subzero Temperature ◽  
Freezing Process ◽  
Pressure Treatment ◽  
Bacterial Cells ◽  
Smoked Salmon

High pressure processing is a novel food preservation technology, applied for over 15 years in the food industry to inactivate spoilage and pathogenic microorganisms. Many studies have shown the differential resistance of bacterial cells to high pressure. Listeria monocytogenes is a bacterium able to grow at refrigerated temperature and to survive for a long time in minimally processed foods such as raw smoked fish. The freezing process does not cause significant decline of L. monocytogenes. The phase diagram of water under pressure permits a pressure treatment under subzero temperature, without the disadvantages of freezing for food quality. The aim of this study was to estimate if combined effects of pressure and subzero temperature could increase the destruction of L. monocytogenes in buffer and in smoked salmon. We investigated effects of high pressure processing (100, 150, and 200 MPa) combined with subzero temperatures (−10, −14, and −18°C) and pH (7.0 and 4.5). Results showed that the most effective high-pressure treatment to inactivate L. monocytogenes was 200 MPa, −18°C, and pH 4.5. The relevance of pressure holding time and the synergistic effect of pressure coupled with the subzero temperature to inactivate bacteria are highlighted. Modifications of physical properties (color and texture) were a lightening of color and an increase of toughness, which might be accepted by consumers, since safety is increased.

Temperature Effects on the Antimicrobial Efficacy of Condensed Smoke and Lauric Arginate against Listeria and Salmonella

2014 ◽  
Vol 77 (6) ◽  
pp. 934-940 ◽  
Author(s):  
JODY M. LINGBECK ◽  
PAOLA CORDERO ◽  
CORLISS A. O'BRYAN ◽  
MICHAEL G. JOHNSON ◽  
STEVEN C. RICKE ◽  
...  
Keyword(s):  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Storage Temperature ◽  
Antimicrobial Properties ◽  
Food Preservation ◽  
Lauric Arginate ◽  
Serovar Typhimurium ◽  
Serotype 1 ◽  
Serotype 4B ◽  
Incubation Temperatures

Condensed smoke or liquid smoke (LS) and lauric arginate (LAE) are antimicrobials used in food preservation. They have demonstrated abilities to reduce or inhibit pathogenic and spoilage organisms. Few studies, however, have reported on the effectiveness of LS or LAE over the range of temperatures typically encountered in food marketing channels. Therefore, the effects of temperature on the antimicrobial properties of two commercial LS fractions, an LS derived from pecan shells, and LAE against two common foodborne pathogens, Listeria and Salmonella, were investigated. The MICs of the three LS samples and LAE were measured at 4, 10, and 37°C for Listeria monocytogenes strains 2045 (Scott A, serotype 4b) and 10403S (serotype 1/2a) and two strains of Listeria innocua, a well-established surrogate, and at 10, 25, and 37°C for Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Heidelberg. The MICs for LS against Listeria ranged from 3 to 48% (vol/vol), with higher MICs seen with lower temperatures. The MICs for LS on Salmonella ranged from 3 to 24%. Values for LAE ranged between 0.004 and 0.07% for both pathogens, and like LS, higher MICs were always associated with lower incubation temperatures. Understanding how storage temperature affects the efficacy of antimicrobials is an important factor that can contribute to lowering the hurdles of use levels and costs of antimicrobials and ultimately improve food safety for the consumer.

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