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Tonti M, Verheyen D, Kozak D, Skåra T, Van Impe JFM. Radio frequency inactivation of Salmonella Typhimurium and Listeria monocytogenes in skimmed and whole milk powder. Int J Food Microbiol 2024; 413:110556. [PMID: 38244386 DOI: 10.1016/j.ijfoodmicro.2023.110556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 12/18/2023] [Accepted: 12/30/2023] [Indexed: 01/22/2024]
Abstract
Milk powder is a convenient, shelf-stable food ingredient used in a variety of food products. However, pathogenic bacteria can be present and survive during prolonged storage, leading to outbreaks of foodborne diseases and product recalls. Radio frequency (RF) heating is a processing technology suitable for bulk treatment of milk powder, aiming at microbial inactivation. This study investigates the RF inactivation of Salmonella Typhimurium and Listeria monocytogenes in two types of milk powder; skimmed and whole milk powder. Specifically, the aims were to (i) examine the influence of the powder's composition on bacterial inactivation, (ii) evaluate the response of bacteria with different Gram properties (Gram positive and Gram negative) and (iii) verify the use of Enterococcus faecium as a surrogate for the two microorganisms for the specific RF process. In order to examine exclusively the influence of RF, a non-isothermal temperature profile was used, employing solely different RF energy levels to heat the product to the target temperatures. A log-linear model with a Bigelow-type temperature dependency was fitted to the experimental data. S. Typhimurium was less susceptible to RF treatments in comparison to L.monocytogenes, demonstrating a higher inactivation rate (k) and higher percentage of sublethal injury. A higher k was also observed for both microorganisms in the whole milk powder, indicating that the increased fat content and decreased levels of lactose and protein in the milk powder had an adverse impact on the microbial survival for both pathogens. The surrogate microorganism E. faecium successfully validated the microbial response of the two microorganisms to RF treatments. In general, a low heating rate RF-only process was successful in inactivating the two foodborne pathogens in skimmed and whole milk powder by 4 log(CFU/g).
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Affiliation(s)
- Maria Tonti
- BioTeC+ - Chemical and Biochemical Process Technology and Control, KU Leuven, Gebroeders de Smetstraat 1, 9000 Gent, Belgium; OPTEC, Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium; CPMF(2), Flemish Cluster Predictive Microbiology in Foods - www.cpmf2.be, Belgium.
| | - Davy Verheyen
- BioTeC+ - Chemical and Biochemical Process Technology and Control, KU Leuven, Gebroeders de Smetstraat 1, 9000 Gent, Belgium; OPTEC, Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium; CPMF(2), Flemish Cluster Predictive Microbiology in Foods - www.cpmf2.be, Belgium.
| | - Dmytro Kozak
- BioTeC+ - Chemical and Biochemical Process Technology and Control, KU Leuven, Gebroeders de Smetstraat 1, 9000 Gent, Belgium; OPTEC, Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium; CPMF(2), Flemish Cluster Predictive Microbiology in Foods - www.cpmf2.be, Belgium.
| | | | - Jan F M Van Impe
- BioTeC+ - Chemical and Biochemical Process Technology and Control, KU Leuven, Gebroeders de Smetstraat 1, 9000 Gent, Belgium; OPTEC, Optimization in Engineering Center-of-Excellence, KU Leuven, Belgium; CPMF(2), Flemish Cluster Predictive Microbiology in Foods - www.cpmf2.be, Belgium.
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Carlin CR, Akins-Lewenthal D, Bastin B, Crowley E, McMahon W, Ziebell B. An Alternative Rapid Confirmation Method for Identifying Listeria monocytogenes from a Variety of 125 g Food Samples Within Two Days of a PCR Presumptive Positive. J Food Prot 2024; 87:100193. [PMID: 37967767 DOI: 10.1016/j.jfp.2023.100193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/17/2023]
Abstract
Cultural confirmation following detection of a Listeria monocytogenespresumptive positive can take 3-7 days to finalize; this uncertainty is a point of frustration for food producers needing to make time-sensitive disposition decisions. To address the demand for shortened time-to-results, an alternative L. monocytogenes confirmation method consisting of two components, (i) a secondary screen using a different rapid method, and (ii) concurrent cultural isolation followed by next-day colony identification was evaluated. For the study, four food matrices (hot dogs, peanut butter, frozen vegetables, and multicomponent frozen meals) were inoculated with low levels (0.36-1.39 MPN/125 g) of L. monocytogenes per the AOAC guidelines for a matrix study. Analyses were performed on 125 g test portions and started with a PCR primary screen (Bio-Rad iQ-Check Listeria monocytogenes II). Next, all enriched food samples underwent a secondary screen by bioMérieux's GENE-UP LMO2 Real-Time PCR and VIDAS LMX ELFA along with streaking onto RAPID'L.mono Agar. Presumptive positive L. monocytogenes colonies were identified utilizing a high throughput rapid identification method (Hygiena's BAX System L. monocytogenes Real-Time PCR assay, Neogen's ANSR isothermal nucleic acid amplification assay, and Bruker's MALDI Biotyper). Importantly, this study evaluated multiple commercially available options for the secondary screen (n = 2) and rapid identification (n = 3) to allow for easy adoption by testing laboratories. Overall, there was no statistically significant difference (p ≤ 0.05) between the number of L. monocytogenes-positive 125 g samples obtained by the cultural reference method and the alternative confirmation methods (regardless of which method combinations were evaluated). Additionally, this study supports that, when both the primary and secondary screen methods yield a positive result, the sample could be considered a confirmed positive for L. monocytogenes.
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Affiliation(s)
| | - Deann Akins-Lewenthal
- ConAgra - Center for Research and Development, Conagra Brands, Inc., Six Conagra Drive, Omaha, NE 68102, USA
| | - Benjamin Bastin
- Q Laboratories, 1930 Radcliff Drive, Cincinnati, OH 45204, USA
| | - Erin Crowley
- Q Laboratories, 1930 Radcliff Drive, Cincinnati, OH 45204, USA
| | - Wendy McMahon
- Mérieux NutriSciences, 3600 Eagle Nest Dr., Crete, IL 60417, USA
| | - Bradley Ziebell
- ConAgra - Center for Research and Development, Conagra Brands, Inc., Six Conagra Drive, Omaha, NE 68102, USA.
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3
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Kaur A, Yemmireddy V. Effect of Different Pre-Growth Temperatures on the Survival Kinetics of Salmonella enterica and Listeria monocytogenes in Fresh-Cut Salad during Refrigerated Storage. Foods 2023; 12:4287. [PMID: 38231743 DOI: 10.3390/foods12234287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/14/2023] [Accepted: 11/22/2023] [Indexed: 01/19/2024] Open
Abstract
The effect of the pre-growth temperature of bacterial cultures on their subsequent survival kinetics in fresh-cut produce during refrigerated storage was investigated in this study. Three-strain cocktails of Listeria monocytogenes and Salmonella enterica, cultured at different growth temperatures (4, 21, and 37 °C) were inoculated on fresh-cut mixed salad and on individual produce in the mixed salad. The inoculated samples were stored at 4 °C and 80 ± 2% relative humidity (RH) for up to 72 h and the growth, survival, or death kinetics were determined at regular intervals. The results indicate that depending upon the type of pathogen tested, the pre-growth temperature(s) and the type of produce showed a significant (p ≤ 0.05) effect on the survival kinetics. Among the tested produce, mixed salad showed the highest reduction in L. monocytogenes pre-grown at 37 °C (1.33 log CFU/g) followed by red cabbage (0.56 log CFU/g), iceberg lettuce (0.52 log CFU/g), and carrot (-0.62 log CFU/g), after 72 h, respectively. In the case of Salmonella, carrot showed the highest reduction (1.07 log CFU/g for 37 °C pre-grown culture) followed by mixed salad (0.78 log CFU/g for 37 °C pre-grown culture), cabbage (0.76 log CFU/g for 21 °C pre-grown culture), and lettuce (0.65 log CFU/g for 4 °C pre-grown culture), respectively. Among the tested ComBase predictive models, the Baranyi-Roberts model better fitted the experimental data. These findings indicate that the appropriate selection of pre-growth environmental conditions is critical to better understand the kinetics of foodborne pathogens.
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Affiliation(s)
- Avninder Kaur
- School of Integrative Biological and Chemical Sciences, The University of Texas Rio Grande Valley, 1201 W University Dr, Edinburg, TX 78539, USA
| | - Veerachandra Yemmireddy
- School of Integrative Biological and Chemical Sciences, The University of Texas Rio Grande Valley, 1201 W University Dr, Edinburg, TX 78539, USA
- School of Earth, Environmental and Marine Sciences, The University of Texas Rio Grande Valley, 1201 W University Dr, Edinburg, TX 78539, USA
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Kiel S, Poverenov E. Rechargeable films for protection of dry foods: A sustainable method for covalent grafting of β-cyclodextrin-thymol complex on PET/viscose platform. Food Chem 2023; 412:135560. [PMID: 36708674 DOI: 10.1016/j.foodchem.2023.135560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/27/2022] [Accepted: 01/22/2023] [Indexed: 01/24/2023]
Abstract
Rechargeable materials for the effective protection of dry food products were developed. β-cyclodextrin-thymol inclusion complex was covalently grafted on a solid platform of polyethylene terephthalate-viscose using either traditional cross-linker of epichlorohydrin, or natural cross-linker of citric acid. A correlation between the grafting method and physicochemical properties, loading capacity and release capabilities of the resulted materials was studied. The developed materials demonstrated antimicrobial properties preventing mold propagation in wheat grains. The treated grains showed normal germination abilities verifying that the prepared materials can protect dry food products without using harmful chemicals. The suggested approach can be extended to other applications and active agents. A combination of rechargeable films with natural volatiles can serve as an effective platform for sustainable active materials for food protection and in other fields such as agriculture, cosmetics, and medicine.
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Affiliation(s)
- Stella Kiel
- Argo-Nanotechnology and Advanced Materials Research Center, Department of Food Science, Agriculture Research Organization, The Volcani Institute, Rishon Lezion 7505101, Israel
| | - Elena Poverenov
- Argo-Nanotechnology and Advanced Materials Research Center, Department of Food Science, Agriculture Research Organization, The Volcani Institute, Rishon Lezion 7505101, Israel.
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Alonso VPP, Gonçalves MPMBB, de Brito FAE, Barboza GR, Rocha LDO, Silva NCC. Dry surface biofilms in the food processing industry: An overview on surface characteristics, adhesion and biofilm formation, detection of biofilms, and dry sanitization methods. Compr Rev Food Sci Food Saf 2023; 22:688-713. [PMID: 36464983 DOI: 10.1111/1541-4337.13089] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 11/14/2022] [Accepted: 11/18/2022] [Indexed: 12/09/2022]
Abstract
Bacterial biofilm formation in low moisture food processing (LMF) plants is related to matters of food safety, production efficiency, economic loss, and reduced consumer trust. Dry surfaces may appear dry to the naked eye, however, it is common to find a coverage of thin liquid films and microdroplets, known as microscopic surface wetness (MSW). The MSW may favor dry surface biofilm (DSB) formation. DSB formation is similar in other industries, it occurs through the processes of adhesion, production of extracellular polymeric substances, development of microcolonies and maturation, it is mediated by a quorum sensing (QS) system and is followed by dispersal, leading to disaggregation. Species that survive on dry surfaces develop tolerance to different stresses. DSB are recalcitrant and contribute to higher resistance to sanitation, becoming potential sources of contamination, related to the spoilage of processed products and foodborne disease outbreaks. In LMF industries, sanitization is performed using physical methods without the presence of water. Although alternative dry sanitizing methods can be efficiently used, additional studies are still required to develop and assess the effect of emerging technologies, and to propose possible combinations with traditional methods to enhance their effects on the sanitization process. Overall, more information about the different technologies can help to find the most appropriate method/s, contributing to the development of new sanitization protocols. Thus, this review aimed to identify the main characteristics and challenges of biofilm management in low moisture food industries, and summarizes the mechanisms of action of different dry sanitizing methods (alcohol, hot air, UV-C light, pulsed light, gaseous ozone, and cold plasma) and their effects on microbial metabolism.
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Affiliation(s)
- Vanessa Pereira Perez Alonso
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Maria Paula M B B Gonçalves
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | | | - Giovana Rueda Barboza
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Liliana de Oliveira Rocha
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
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Alves Â, Santos-Ferreira N, Magalhães R, Ferreira V, Teixeira P. From chicken to salad: Cooking salt as a potential vehicle of Salmonella spp. and Listeria monocytogenes cross-contamination. Food Control 2022; 137:108959. [PMID: 35783559 PMCID: PMC9025383 DOI: 10.1016/j.foodcont.2022.108959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/16/2022]
Abstract
Epidemiological studies show that improper food handling practices at home account for a significant portion of foodborne illness cases. Mishandling of raw meat during meal preparation is one of the most frequent hazardous behaviours reported in observational research studies that potentially contributes to illness occurrence, particularly through the transfer of microbial pathogens from the raw meat to ready-to-eat (RTE) foods. This study evaluated the transfer of two major foodborne pathogens, Salmonella enterica and Listeria monocytogenes, from artificially contaminated chicken meat to lettuce via cooking salt (used for seasoning) during simulated domestic handling practices. Pieces of chicken breast fillets were spiked with five different loads (from ca. 1 to 5 Log CFU/g) of a multi-strain cocktail of either S. enterica or L. monocytogenes. Hands of volunteers (gloved) contaminated by handling the chicken, stirred the cooking salt that was further used to season lettuce leaves. A total of 15 events of cross-contamination (three volunteers and five bacterial loads) were tested for each pathogen. Immediately after the events, S. enterica was isolated from all the cooking salt samples (n = 15) and from 12 samples of seasoned lettuce; whereas L. monocytogenes was isolated from 13 salt samples and from all the seasoned lettuce samples (n = 15). In addition, S. enterica and L. monocytogenes were able to survive in artificially contaminated salt (with a water activity of 0.49) for, at least, 146 days and 126 days, respectively. The ability of these foodborne pathogens to survive for a long time in cooking salt, make it a good vehicle for transmission and cross-contamination if consumers do not adopt good hygiene practices when preparing meals. Pathogens may contaminate cooking salt via cross-contamination from unwashed hands. Salmonella enterica and Listeria monocytogenes survive on salt for several weeks. Pathogens are transmitted from contaminated chicken to hands, and then to salt. L. monocytogenes and S. enterica present in lettuce seasoned with contaminated salt.
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7
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Recent development in low-moisture foods: Microbial safety and thermal process. Food Res Int 2022; 155:111072. [DOI: 10.1016/j.foodres.2022.111072] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/17/2022]
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8
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Porto-Fett ACS, McCoy A, Shane LE, Henry E, Osoria M, Shoyer BA, Campano SG, Burson D, Luchansky JB. Fate of Listeria monocytogenes and Shiga Toxin-Producing Escherichia coli on Slices of Beef Bresaola During Refrigerated Storage. MEAT AND MUSCLE BIOLOGY 2022. [DOI: 10.22175/mmb.13918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The viability of multi-strain cocktails of geneticallymarked strains of Listeriamonocytogenes and Shigatoxin-producing Escherichiacoli (STEC) wereseparately monitored on slices of one brand of a commercially-producedbresaola (ca. pH 6.7 and aw 0.899) during extendedrefrigerated storage. Two slices (ca. 8 g each; ca. 10.2 cm wide, ca. 11 cmlong) of bresaola were layered horizontally within a nylon-polyethylene bag.The outer surface of each slice was inoculated (50 µL total; ca. 3.5 logCFU/package)with a rifampicin-resistant (100 mg/ml)cocktail of either L.monocytogenes (fivestrains) or STEC (eight strains). Bags were vacuum-sealed and then stored at 4°or 10°C for 180 or 90 days, respectively. In each of five trials, three bagswere analyzed for pathogen presence at each sampling interval via the USDA-ARSpackage rinse method. In general, levels of L. monocytogenes and STEC decreased by 3.0and 2.4log CFU/package, respectively, after 180 days when bresaola was stored at 4°C.When bresaola was stored at 10°C for 90 days, levels of L. monocytogenes and STEC decreased by 2.4 and 3.1log CFU/package, respectively. Thus, the (brand of) sliced bresaola evaluatedherein did not provide a favorable environment for either persistence oroutgrowth of surface-inoculated cells of L. monocytogenes or STEC.
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Affiliation(s)
- Anna C. S. Porto-Fett
- USDA, ARS, Eastern Regional research Center Food Safety and Interventions Technologies
| | - Ashley McCoy
- University of Nebraska Department of Animal Science
| | - Laura E. Shane
- USDA, ARS, Eastern Regional research Center Food Safety and Interventions Technologies
| | - Elizabeth Henry
- USDA, ARS, Eastern Regional research Center Food Safety and Interventions Technologies
| | - Manuela Osoria
- USDA, ARS, Eastern Regional research Center Food Safety and Interventions Technologies
| | - Bradley A. Shoyer
- USDA, ARS, Eastern Regional research Center Food Safety and Interventions Technologies
| | | | | | - John B. Luchansky
- USDA, ARS, Eastern Regional research Center Food Safety and Interventions Technologies
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Wu X, Chen Q, Yang C, Ning Q, Liu Z. An enhanced visual detection assay for Listeria monocytogenes in food based on isothermal amplified peroxidase-mimicking catalytic beacon. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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10
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Bourdichon F, Betts R, Dufour C, Fanning S, Farber J, McClure P, Stavropoulou DA, Wemmenhove E, Zwietering MH, Winkler A. Processing environment monitoring in low moisture food production facilities: Are we looking for the right microorganisms? Int J Food Microbiol 2021; 356:109351. [PMID: 34500287 DOI: 10.1016/j.ijfoodmicro.2021.109351] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/16/2021] [Accepted: 07/28/2021] [Indexed: 11/27/2022]
Abstract
Processing environment monitoring is gaining increasing importance in the context of food safety management plans/HACCP programs, since past outbreaks have shown the relevance of the environment as contamination pathway, therefore requiring to ensure the safety of products. However, there are still many open questions and a lack of clarity on how to set up a meaningful program, which would provide early warnings of potential product contamination. Therefore, the current paper aims to summarize and evaluate existing scientific information on outbreaks, relevant pathogens in low moisture foods, and knowledge on indicators, including their contribution to a "clean" environment capable of limiting the spread of pathogens in dry production environments. This paper also outlines the essential elements of a processing environment monitoring program thereby supporting the design and implementation of better programs focusing on the relevant microorganisms. This guidance document is intended to help industry and regulators focus and set up targeted processing environment monitoring programs depending on their purpose, and therefore provide the essential elements needed to improve food safety.
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Affiliation(s)
- François Bourdichon
- Food Safety, Microbiology, Hygiene, 16 Rue Gaston de Caillavet, 75015 Paris, France; Facoltà di Scienze Agrarie, Alimentarie Ambientali, Università Cattolica del Sacro Cuore, Piacenza-Cremona, Italy.
| | - Roy Betts
- Campden BRI, Chipping Campden, Gloucestershire, United Kingdom
| | - Christophe Dufour
- Mérieux NutriSciences, 25 Boulevard de la Paix, 95891 Cergy Pontoise, France
| | - Séamus Fanning
- UCD - Centre for Food Safety, University College Dublin, Belfield, Dublin D04 N2E5, Ireland
| | - Jeffrey Farber
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Peter McClure
- Mondelēz International, Bournville Lane, Birmingham B30 2LU, United Kingdom
| | | | | | - Marcel H Zwietering
- Food Microbiology, Wageningen University, PO Box 17, 6700AA, Wageningen, The Netherlands
| | - Anett Winkler
- Cargill Germany GmbH, Cerestar str. 2, D-47809 Krefeld, Germany
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12
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Harada AM, Nascimento MS. Efficacy of dry sanitizing methods on Listeria monocytogenes biofilms. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107897] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Deng LZ, Sutar PP, Mujumdar AS, Tao Y, Pan Z, Liu YH, Xiao HW. Thermal Decontamination Technologies for Microorganisms and Mycotoxins in Low-Moisture Foods. Annu Rev Food Sci Technol 2021; 12:287-305. [PMID: 33317321 DOI: 10.1146/annurev-food-062220-112934] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The contamination risks of microorganisms and mycotoxins in low-moisture foods have heightened public concern. Developing novel decontamination technologies to improve the safety of low-moisture foods is of great interest in both economics and public health. This review summarizes the working principles and applications of novel thermal decontamination technologies such as superheated steam, infrared, microwave, and radio-frequency heating as well as extrusion cooking. These methods of decontamination can effectively reduce the microbial load on products andmoderately destruct the mycotoxins. Meanwhile, several integrated technologies have been developed that take advantage of synergistic effects to achieve the maximum destruction of contaminants and minimize the deterioration of products.
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Affiliation(s)
- Li-Zhen Deng
- College of Engineering, China Agricultural University, 100083 Beijing, China; .,State Key Laboratory of Food Science and Technology, Nanchang University, 330047 Nanchang, China
| | - Parag Prakash Sutar
- Department of Food Process Engineering, National Institute of Technology, Rourkela, Odisha 769008, India
| | - Arun S Mujumdar
- Department of Bioresource Engineering, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, 210095 Nanjing, China
| | - Zhongli Pan
- Department of Biological and Agricultural Engineering, University of California, Davis, California 95616, USA
| | - Yan-Hong Liu
- College of Engineering, China Agricultural University, 100083 Beijing, China;
| | - Hong-Wei Xiao
- College of Engineering, China Agricultural University, 100083 Beijing, China;
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14
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Zhang G, Hu L, Luo Y, Santillana Farakos SM, Johnson R, Scott VN, Curry P, Melka D, Brown EW, Strain E, Bunning VK, Musser SM, Hammack TS. Survey of Salmonella in raw tree nuts at retail in the United States. J Food Sci 2021; 86:495-504. [PMID: 33438200 PMCID: PMC7898309 DOI: 10.1111/1750-3841.15569] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 12/01/2022]
Abstract
Abstract The objective of this survey was to estimate the prevalence, contamination level, and genetic diversity of Salmonella in selected raw, shelled tree nuts (Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts) at retail markets in the United States. A total of 3,374 samples of eight tree nuts were collected from different types of retail stores and markets nationwide between September 2015 and March 2017. These samples (375 g) were analyzed using a modified FDA's BAM Salmonella culture method. Of the 3,374 samples, 15 (0.44%) (95% confidence interval [CI] [0.25, 0.73]) were culturally confirmed as containing Salmonella; 17 isolates were obtained. Among these isolates, there were 11 serotypes. Salmonella was not detected in Brazil nuts (296), hazelnuts (487), pecans (510), pine nuts (500), and walnuts (498). Salmonella prevalence estimates in cashews (510), macadamia (278), and pistachios (295) were 0.20% (95% CI [<0.01, 1.09]), 2.52% (95% CI [1.02, 5.12]), and 2.37% (95% CI [0.96, 4.83]), respectively. The rates of Salmonella isolation from major/big‐chain supermarkets (1381), small‐chain supermarkets (328), discount/variety/drug stores (1329), and online (336) were 0.29% (95% CI [0.08, 0.74]), 0.30% (95% CI [0.01, 1.69]), 0.45% (95% CI [0.17, 0.98]), and 1.19% (95% CI [0.33, 3.02]), respectively. Salmonella prevalence in organic (530) and conventional (2,844) nuts was not different statistically (P = 0.0601). Of the enumerated samples (15), 80% had Salmonella levels ≤0.0092 most probable number (MPN)/g. The highest contamination level observed was 0.75 MPN/g. The prevalence and contamination levels of Salmonella in the tree nuts analyzed were generally comparable to previous reports. Pulsed‐field gel electrophoresis, serotype, and sequencing data all demonstrated that Salmonella population in nuts is very diverse genetically. Practical Application The prevalence, contamination level, and genetic diversity of Salmonella in eight types of tree nuts (3,374 samples collected nationwide) revealed in this survey could help the development of mitigation strategies to reduce public health risks associated with consumption of these nuts.
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Affiliation(s)
- Guodong Zhang
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Lijun Hu
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Yan Luo
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Sofia M Santillana Farakos
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Rhoma Johnson
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Virginia N Scott
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Phillip Curry
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - David Melka
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Eric W Brown
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Errol Strain
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Vincent K Bunning
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Steven M Musser
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
| | - Thomas S Hammack
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5001 Campus Dr., College Park, MD, 20740, U.S.A
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15
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Ly V, Parreira VR, Sanchez-Maldonado AF, Farber JM. Survival and Virulence of Listeria monocytogenes during Storage on Chocolate Liquor, Corn Flakes, and Dry-Roasted Shelled Pistachios at 4 and 23°C. J Food Prot 2020; 83:1852-1862. [PMID: 32556209 DOI: 10.4315/jfp-20-129] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/15/2020] [Indexed: 12/17/2022]
Abstract
ABSTRACT The survival and virulence of Listeria monocytogenes was assessed during storage on three low-moisture foods (LMFs): chocolate liquor, corn flakes, and shelled, dry-roasted pistachios (water activity [aw] of 0.18, 0.27, and 0.20, respectively). The LMFs were inoculated with a four-strain cocktail of L. monocytogenes at 8 log CFU/g, dried, held until the aw stabilized, and then stored at 4°C and 25 to 81% relative humidity (RH) and at 23°C and 30 to 35% RH for at least 336 days. At 4°C, L. monocytogenes remained stable on the LMFs for at least 336 days. At 23°C, L. monocytogenes levels declined on the chocolate liquor, corn flakes, and pistachios at initial rates of 0.84, 0.88, and 0.32 log CFU/g/month, respectively. After 8 months at 23°C, L. monocytogenes levels on the chocolate liquor and corn flakes decreased to below the limit of detection (i.e., 0.48 log CFU/g). Relative populations of each strain were assessed before storage (i.e., day 0) and after 6 and 12 months of storage at 23 and 4°C, respectively. Generally, a decline in the relative level of the serotype 1/2a strain was observed during storage, coupled with the relative increase in other strains, depending on the LMF and storage temperature. The total viable populations of L. monocytogenes determined by the PMAxx quantitative PCR method after >12 months of storage at 4°C were significantly (1.8- to 3.7-log) higher than those obtained by plating on tryptic soy agar with yeast extract. Decreases in the culturable population of L. monocytogenes during storage on the LMFs were the result of both cellular inactivation and transition to a viable-but-nonculturable state. The surviving cells, specifically after long-term storage at 4°C on the chocolate liquor and pistachios, remained infectious and capable of intracellular replication in Caco-2 enterocytes. These results are relevant for predictive modeling used in microbial health risk assessments and support the addition of LMFs to food safety questionnaires conducted during listeriosis outbreaks. HIGHLIGHTS
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Affiliation(s)
- Vivian Ly
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - Valeria R Parreira
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.,(ORCID: https://orcid.org/0000-0002-7073-1955 [V.R.P.])
| | - Alma Fernanda Sanchez-Maldonado
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - Jeffrey M Farber
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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16
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Hasani M, Wu F, Hu K, Farber J, Warriner K. Inactivation of Salmonella and Listeria monocytogenes on dried fruit, pistachio nuts, cornflakes and chocolate crumb using a peracetic acid-ethanol based sanitizer or Advanced Oxidation Process. Int J Food Microbiol 2020; 333:108789. [DOI: 10.1016/j.ijfoodmicro.2020.108789] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 12/28/2022]
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17
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Wambui J, Eshwar AK, Aalto-Araneda M, Pöntinen A, Stevens MJA, Njage PMK, Tasara T. The Analysis of Field Strains Isolated From Food, Animal and Clinical Sources Uncovers Natural Mutations in Listeria monocytogenes Nisin Resistance Genes. Front Microbiol 2020; 11:549531. [PMID: 33123101 PMCID: PMC7574537 DOI: 10.3389/fmicb.2020.549531] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/02/2020] [Indexed: 12/19/2022] Open
Abstract
Nisin is a commonly used bacteriocin for controlling spoilage and pathogenic bacteria in food products. Strains possessing high natural nisin resistance that reduce or increase the potency of this bacteriocin against Listeria monocytogenes have been described. Our study sought to gather more insights into nisin resistance mechanisms in natural L. monocytogenes populations by examining a collection of 356 field strains that were isolated from different foods, food production environments, animals and human infections. A growth curve analysis-based approach was used to access nisin inhibition levels and assign the L. monocytogenes strains into three nisin response phenotypic categories; resistant (66%), intermediate (26%), and sensitive (8%). Using this categorization isolation source, serotype, genetic lineage, clonal complex (CC) and strain-dependent natural variation in nisin phenotypic resistance among L. monocytogenes field strains was revealed. Whole genome sequence analysis and comparison of high nisin resistant and sensitive strains led to the identification of new naturally occurring mutations in nisin response genes associated with increased nisin resistance and sensitivity in this bacterium. Increased nisin resistance was detected in strains harboring RsbUG77S and PBPB3V240F amino acid substitution mutations, which also showed increased detergent stress resistance as well as increased virulence in a zebra fish infection model. On the other hand, increased natural nisin sensitivity was detected among strains with mutations in sigB, vir, and dlt operons that also showed increased lysozyme sensitivity and lower virulence. Overall, our study identified naturally selected mutations involving pbpB3 (lm0441) as well as sigB, vir, and dlt operon genes that are associated with intrinsic nisin resistance in L. monocytogenes field strains recovered from various food and human associated sources. Finally, we show that combining growth parameter-based phenotypic analysis and genome sequencing is an effective approach that can be useful for the identification of novel nisin response associated genetic variants among L. monocytogenes field strains.
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Affiliation(s)
- Joseph Wambui
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Athmanya K Eshwar
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Mariella Aalto-Araneda
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Anna Pöntinen
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Marc J A Stevens
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Patrick M K Njage
- Research Group for Genomic Epidemiology, Division for Global Surveillance, National Food Institute, Technical University of Denmark, Kengens Lyngby, Denmark
| | - Taurai Tasara
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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18
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Charoux CMG, Patange A, Lamba S, O'Donnell CP, Tiwari BK, Scannell AGM. Applications of nonthermal plasma technology on safety and quality of dried food ingredients. J Appl Microbiol 2020; 130:325-340. [PMID: 32797725 DOI: 10.1111/jam.14823] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/20/2020] [Accepted: 08/06/2020] [Indexed: 12/28/2022]
Abstract
Cold plasma technology is an efficient, environmental-friendly, economic and noninvasive technology; and in recent years these advantages placed this novel technology at the centre of diverse studies for food industry applications. Dried food ingredients including spices, herbs, powders and seeds are an important part of the human diet; and the growing demands of consumers for higher quality and safe food products have led to increased research into alternative decontamination methods. Numerous studies have investigated the effect of nonthermal plasma on dried food ingredients for food safety and quality purposes. This review provides critical review on potential of cold plasma for disinfection of dried food surfaces (spices, herbs and seeds), improvement of functional and rheological properties of dried ingredients (powders, proteins and starches). The review further highlights the benefits of plasma treatment for enhancement of seeds performance and germination yield which could be applied in agricultural sector in near future. Different studies applying plasma technology for control of pathogens and spoilage micro-organisms and modification of food quality and germination of dried food products followed by benefits and current challenges are presented. However, more systemic research needs to be addressed for successful adoption of this technology in food industry.
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Affiliation(s)
- C M G Charoux
- Food Chemistry and Technology, Teagasc Food Research Centre, Dublin, Ireland.,UCD School of Biosystems and Food Engineering, University College Dublin, Dublin, Ireland
| | - A Patange
- Food Chemistry and Technology, Teagasc Food Research Centre, Dublin, Ireland
| | - S Lamba
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - C P O'Donnell
- UCD School of Biosystems and Food Engineering, University College Dublin, Dublin, Ireland
| | - B K Tiwari
- Food Chemistry and Technology, Teagasc Food Research Centre, Dublin, Ireland.,UCD School of Biosystems and Food Engineering, University College Dublin, Dublin, Ireland
| | - A G M Scannell
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
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19
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Moussavi M, Frelka JC, Hildebrandt IM, Marks BP, Harris LJ. Thermal Resistance of Foodborne Pathogens and Enterococcus faecium NRRL B-2354 on Inoculated Pistachios. J Food Prot 2020; 83:1125-1136. [PMID: 32084255 DOI: 10.4315/jfp-19-561] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/20/2020] [Indexed: 12/25/2022]
Abstract
ABSTRACT Process control validations require knowledge of the resistance of the pathogen(s) of concern to the target treatment and, in some cases, the relative resistance of surrogate organisms. Selected strains of Escherichia coli O157:H7 (five strains), Listeria monocytogenes (five strains), and Salmonella enterica (five strains) as well as Salmonella Enteritidis phage type (PT) 30 and nonpathogenic Enterococcus faecium NRRL B-2354 were inoculated separately (as individual strains) onto inshell pistachios. The thermal tolerance of each strain was compared via treatment of inoculated pistachios to hot oil (121°C) or hot water (80°C) for 1 min. Survivor curves in hot oil or hot water (0.5 to 6 min, n = 6 to 15) were determined for one or two of the most resistant strains of each pathogen, as well as E. faecium NRRL B-2354 and Salmonella Enteritidis PT 30, and the Weibull model was fit to the data. A pilot-scale air-impingement oven was used to compare the thermal tolerance of E. faecium NRRL B-2354 and Salmonella Enteritidis PT 30 on pistachios with or without a brining pretreatment and at either dry (no steam) or 30% humidity (v/v) oven conditions. No significant difference in the time to a 4-log reduction in hot oil or hot water was predicted for any of the strains evaluated, on the basis of the 95% confidence interval. In the pilot-scale oven, E. faecium NRRL B-2354 was more thermally resistant than Salmonella in a broad set of differing treatments, treatment times, and temperatures. Salmonella is a suitable target pathogen of concern in pistachios for thermal processes because no other pathogen tested was more thermally resistant under the conditions evaluated. E. faecium NRRL B-2354 was at least as thermally resistant as Salmonella under all conditions evaluated, making it a good potential surrogate for Salmonella on pistachios. HIGHLIGHTS
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Affiliation(s)
- Mahta Moussavi
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, California 95616 (ORCID: https://orcid.org/0000-0002-1911-752X [L.J.H.])
| | - John C Frelka
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, California 95616 (ORCID: https://orcid.org/0000-0002-1911-752X [L.J.H.])
| | - Ian M Hildebrandt
- Department of Biosystems and Agricultural Engineering, Michigan State University, 524 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Bradley P Marks
- Department of Biosystems and Agricultural Engineering, Michigan State University, 524 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Linda J Harris
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, California 95616 (ORCID: https://orcid.org/0000-0002-1911-752X [L.J.H.])
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20
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Olaimat AN, Osaili TM, Al-Holy MA, Al-Nabulsi AA, Obaid RS, Alaboudi AR, Ayyash M, Holley R. Microbial safety of oily, low water activity food products: A review. Food Microbiol 2020; 92:103571. [PMID: 32950156 DOI: 10.1016/j.fm.2020.103571] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/17/2020] [Accepted: 06/13/2020] [Indexed: 12/25/2022]
Abstract
Oily, low water activity (OL aw) products including tahini (sesame seed paste), halva (tahini halva), peanut butter, and chocolate, have been recently linked to numerous foodborne illness outbreaks and recalls. This review discusses the ingredients used and processing of OL aw products with a view to provide greater understanding of the routes of their contamination with foodborne pathogens and factors influencing pathogen persistence in these foods. Adequate heat treatment during processing may eliminate bacterial pathogens from OL aw foods; however, post-processing contamination commonly occurs. Once these products are contaminated, their high fat and sugar content can enhance pathogen survival for long periods. The physiological basis and survival mechanisms used by pathogens in these products are comprehensively discussed here. Foodborne outbreaks and recalls linked to OL aw foods are summarized and it was observed that serotypes of Salmonella enterica were the predominant pathogens causing illnesses. Further, intervention strategies available to control foodborne pathogens such as thermal inactivation, use of natural antimicrobials, irradiation and hydrostatic pressure are assessed for their usefulness to achieve pathogen control and enhance the safety of OL aw foods. Sanitation, hygienic design of manufacturing facilities, good hygienic practices, and environmental monitoring of OL aw food industries were also discussed.
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Affiliation(s)
- Amin N Olaimat
- Department of Clinical Nutrition and Dietetics, Faculty of Applied Medical Sciences, The Hashemite University, P.O. Box 150459, Zarqa, 13115, Jordan.
| | - Tareq M Osaili
- Department of Clinical Nutrition and Dietetics, College of Health Science, University of Sharjah, Sharjah, United Arab Emirates; Department of Nutrition and Food Technology, Jordan University of Science and Technology, P.O. Box 3030, Irbid, 22110, Jordan.
| | - Murad A Al-Holy
- Department of Clinical Nutrition and Dietetics, Faculty of Applied Medical Sciences, The Hashemite University, P.O. Box 150459, Zarqa, 13115, Jordan
| | - Anas A Al-Nabulsi
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, P.O. Box 3030, Irbid, 22110, Jordan
| | - Reyad S Obaid
- Department of Clinical Nutrition and Dietetics, College of Health Science, University of Sharjah, Sharjah, United Arab Emirates
| | - Akram R Alaboudi
- Department of Pathology and Public Health, Faculty of Veterinary Medicine, Jordan University of Science and Technology, P.O. Box 3030, Irbid, 22110, Jordan
| | - Mutamed Ayyash
- Department of Food, Nutrition and Health, College of Food and Agriculture, United Arab Emirates University (UAEU), Al Ain, UAE
| | - Richard Holley
- Department of Food Science and Human Nutrition, University of Manitoba, Winnipeg, Manitoba, R2J 3L8, Canada
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21
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Gelda KS, Parreira VR, LaPOINTE G, Farber JM. Examination of the Culturable Microbiota from Low-Moisture Foods Imported into Canada for Antibacterial Activity against Listeria monocytogenes. J Food Prot 2020; 83:686-691. [PMID: 31855471 DOI: 10.4315/jfp-19-489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 12/10/2019] [Indexed: 11/11/2022]
Abstract
ABSTRACT Listeria monocytogenes, a resilient and ubiquitous foodborne pathogen, is associated with a high case-fatality rate in humans. This study investigated the culturable microbiota of low-moisture foods (LMFs) imported into Canada to see how well bacteria isolated from these foods could inhibit or inactivate the growth of L. monocytogenes. Imported LMFs were acquired from various supermarkets in the Greater Toronto Area (Ontario, Canada). The foods included dried apples, bee pollen, cumin seeds, date fruits, fennel seeds, pistachios, raisins, and seaweed. Bacterial strains were isolated from the foods using blood agar and then screened using an in-house-designed growth inhibition plate assay against L. monocytogenes. The inhibitory strains detected were then identified using 16S rRNA sequencing. Diverse bacteria were recovered from the foods; 236 isolates belonging to 122 observed phenotypes were obtained. From the inhibition plate assays, 10 of the 11 imported LMFs harbored inhibitory strains against L. monocytogenes, whereby 48 of the collected isolates (20%) were found to produce a zone of inhibition against this pathogen. The inhibitory strains belonged to six genera (Acinetobacter, Aerococcus, Bacillus, Lysinibacillus, Paenibacillus, and Sporosarcina) and 15 unique species. Among all foods tested, the date fruit microbiota displayed the greatest number and diversity of anti-L. monocytogenes inhibitory strains. Overall, it was found that the culturable microbiota of LMFs, imported into Canada, possess bacterial members that can inhibit the growth of L. monocytogenes. These results could lead to the discovery of either novel antimicrobial metabolites or beneficial anti-L. monocytogenes bacteria that could be added to foods to inactivate and/or control L. monocytogenes. HIGHLIGHTS
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Affiliation(s)
- Krishna S Gelda
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, 50 Stone Road E., Guelph, Ontario, Canada N1G 2W1.,(ORCID: https://orcid.org/0000-0001-8599-4523 [K.S.G.])
| | - Valeria R Parreira
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, 50 Stone Road E., Guelph, Ontario, Canada N1G 2W1
| | - Gisèle LaPOINTE
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, 50 Stone Road E., Guelph, Ontario, Canada N1G 2W1
| | - Jeffrey M Farber
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, 50 Stone Road E., Guelph, Ontario, Canada N1G 2W1
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22
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Assessment of the Antimicrobial Potentiality and Functionality of Lactobacillus plantarum Strains Isolated from the Conventional Inner Mongolian Fermented Cheese Against Foodborne Pathogens. Pathogens 2019; 8:pathogens8020071. [PMID: 31117307 PMCID: PMC6631976 DOI: 10.3390/pathogens8020071] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/07/2019] [Accepted: 05/13/2019] [Indexed: 12/23/2022] Open
Abstract
Lactobacillus plantarum are amongst the diversified lactic acid bacteria (LAB) species which are being utilized abundantly in the food industry. Numerous L. plantarum strains have been reported to produce several antimicrobial compounds. Diacetyl, hydrogen peroxide, organic acids, as well as bacteriocins can also be exemplified by a variable spectrum of actions. The current study was intended to conduct the screening and characterization of antimicrobial prospective of L. plantarum from traditional Inner Mongolian fermented hard cheese. Foodborne pathogens, Salmonella typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus, were examined by using the Oxford cup technique and the mixed culture inhibition assays. The resulting analyses disclosed that L. plantarum KLDS1.0344 indicated broad antimicrobial spectrum against all selected pathogens as compared to other LAB used in this study. Additionally, the decrement of the pathogen population was observed up to 3.47 logs in mixed culture inhibition assays. L. plantarum KLDS 1.0344 acid production was recorded up to 71.8 ± 3.59 °D in mixed culture while antimicrobial particles released in cell free supernatants demonstrated bacteriocin-like characteristics showing substantial pH stability (2.0–6.0), proteolytic enzyme reduced the antibacterial activity (15.2 ± 0.6 mm–20.4 ± 0.8 mm), heat stability (20 min at 120 °C) against selected pathogens. Moreover, the spectrum range of antimicrobial peptides after the partial purification was decreased as compared to the crude bacteriocin-like compound. The SDS-PAGE analysis showed the molecular weight range of partially purified bacteriocin from 12 to 45 kDa. After analyzing the obtained data from the current experimentation showed that the capability of L. plantarum KLDS 1.0344 to oppose the pathogen growth in vitro relies on the occurrence of organic acids along with bacteriocin-like compounds proving L. plantarum KLDS 1.0344 as a potentially appropriate candidate as an alternative bio-control agent against foodborne pathogens.
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