Source: OKLAHOMA STATE UNIVERSITY submitted to
DECONTAMINATION OF FOODBORNE PATHOGENS ON PRODUCE BY ATMOSPHERIC COLD PLASMA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1006562
Grant No.
(N/A)
Project No.
OKL02999
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2015
Project End Date
Sep 30, 2020
Grant Year
(N/A)
Project Director
Ma, L.
Recipient Organization
OKLAHOMA STATE UNIVERSITY
(N/A)
STILLWATER,OK 74078
Performing Department
Entomology And Plant Pathology
Non Technical Summary
With increasing numbers of foodborne illness and outbreaks associated with the consumption of produce in recent years, the presence of foodborne pathogen on produce is a worldwide food safety & human health concern. Decontamination of produce during processing is a critical step in reducing such risk. However, current technologies based on chemical sanitizers (such as chlorine) or physical treatments often show a limited efficiency in eliminating/reducing such risk. Atmospheric cold plasma (ACP) has gained increasing attention as an alternative nonthermal technology for elimination of microorganisms from contaminated objects, such as food surfaces. We propose, in this project, to develop a surface dielectric barrier discharge (SDBD)-based atmospheric cold plasma device for decontamination of human pathogens on produce. In addition, understanding the underlying mechanisms of cold plasma inactivation of human pathogens at molecular level is not only essential for optimizing its killing power but also critical for the regulatory approval of its future applications in a food system. Therefore, we also propose in this project to elucidate the molecular mechanisms of human pathogen inactivation by cold plasma through RNA-seq Analysis. In the end, we hope to construct cold plasma-based decontamination devices for produce decontamination to improve our food safety as well as to extend our understanding the underlying molecular mechanisms of human pathogen inactivation by cold plasma.
Animal Health Component
0%
Research Effort Categories
Basic
40%
Applied
60%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7125010110060%
4027410202040%
Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins; 402 - Engineering Systems and Equipment;

Subject Of Investigation
7410 - General technology; 5010 - Food;

Field Of Science
2020 - Engineering; 1100 - Bacteriology;
Goals / Objectives
Optimization of cold plasma actuator design for decontamination of human pathogens on produce AND elucidation of molecular mechanisms of human pathogen inactivation by cold plasma.
Project Methods
Microbiological analysis including RNA-seq.

Progress 10/01/15 to 09/30/20

Outputs
Target Audience:Academic research communities, fresh produce and food industries, and governmental regulatory officials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided the opportunity for the graduate and undergraduate students to learn many new techniques and experiment with CAP technology which is considered a new promising approach for improving food safety. How have the results been disseminated to communities of interest?Research results have been disseminated to communities of interest by 1) presentations at international, national professional, and growers' association meetings 2) seminars at international and national institutions; 3) publications at peer-reviewed journals and Ph.D. dissertations. What do you plan to do during the next reporting period to accomplish the goals?All of the objectives of this project have been accomplished. However, we would like to expend the CAP application to the control of mycotoxin-producing fungi in food and feed in the near future.

Impacts
What was accomplished under these goals? All of the objectives of this project have been accomplished: 1. Optimization of cold atmospheric plasma (CAP) actuator design for decontamination of human pathogens: the optimized design (asymmetric arrangement of electrodes) of cold plasma actuator induced more turbulent and high-velocity cold plasma flow which in turn resulted in higher killing efficiency of foodborne pathogens at a longer distance than other design. These results have been published in a peer-reviewed journal article; A patent application has been filed for the device; 2. CAP decontamination of foodborne pathogens on produce: The inactivation efficiency of CAP on Salmonella enterica on in-shell pecans and black peppercorns were evaluated. The results revealed that moistening of pecans or black peppercorns prior to treatment achieved an additional 1-log reduction of Salmonella compared to the treatment without moistening. These results, parts have been published in a peer-reviewed journal article and parts are in a submitted article; 3. Elucidation of molecular mechanisms of human pathogen inactivation by CAP through RNA-seq analysis: The morphological and transcriptomic response of Salmonella Enteritidis to CAP treatment were studied through transmission electron microscopy (TEM) and RNA sequencing (RNA-Seq). Among 764 differentially expressed genes with fold changes greater than 1.50 (P ≤ 0.01, FDR ≤ 0.05), 255 were up-regulated (1.50 to 3.23-fold) and 509 were downregulated (-1.50 top -120.67-fold) after CAP treatment. Genes associated with phosphate uptake, cation uptake, osmoregulation, tetrathionate utilization, phage-shock proteins, and DNA damage repair were significantly downregulated after CAP treatment. Differentially expressed metabolic pathways included upregulation of ethanolamine utilization and downregulation of colonic acid and enterobactin biosynthesis. The observed general decrease in stress responses by CAP-treated Salmonella cells could be a result of rapid lipid peroxidation, cytosolic leakage, and cell lysis, as confirmed by TEM. Parts of these results have been submitted for publication and the remaining data is in preparation for additional peer-reviewed journal articles.

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2020 Citation: C. Timmons, K. Pai, and L. Ma. 2020. Morphological and transcriptomic response of Salmonella Enteritidis to cold plasma treatment. Food Control.
  • Type: Journal Articles Status: Submitted Year Published: 2020 Citation: Diaz, C., J. Diaz, C. Somoza, J. Cuellar, C. Timmons, K. Pai, and L. Ma. 2020. Decontamination of Salmonella enterica on low-moisture foods by cold atmospheric plasma. Food Control.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: L. Ma. 2019. Cold Plasma Technology for Food Decontamination. Oral Presentation. Mexico Association for Food Protection Annual Meeting, Sept 13, 2019, Monterrey, Mexico.


Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Academic research communities, fresh produce and food industries, and governmental regulatory officials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided the opportunity for the graduate and undergraduate students to learn and experiment with cold plasma technology which is considered a new promising approach for improving food safety. How have the results been disseminated to communities of interest?Research results have been disseminated to communities of interest by 1) presentations at international and national professional meetings 2) seminars at international and national institutions; 3) publications at peer-reviewed journals and Ph.D. dissertation. What do you plan to do during the next reporting period to accomplish the goals?Optimization of the cold plasma device for decontamination a variety of produce including tree nuts, spices, and seeds. Also, opportunities for extending the application of cold plasma will be explored (such as feed decontamination).

Impacts
What was accomplished under these goals? Postharvest decontamination treatment is a critical step in reducing food safety risks associated with minimally processed produce, such as fruit, vegetable, and tree nuts. However, current technologies based on chemical sanitizers (such as chlorine) not only have limited inactivation efficiency but also consume a tremendous amount of water, a natural resource. The food industry is constantly on the look for new decontamination technology. Cold plasma, as a dry technology, has the capacity to inactivate microbes including foodborne pathogens on produce surface with a minimum usage of water. In this period of time, we had further optimized the moistening conditions of produce prior to cold plasma treatment in which we achieved 4 log reduction of Salmonella on pecan in 5 min (comparing to 10 min without moistening). Additionally, we had conducted a preliminary effort in scaling up the prototype of CAP device for commercial decontamination application.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: L. Ma. 2019. Cold Plasma Technology for Food Decontamination. Oral Presentation. Mexico Association for Food Protection Annual Meeting, Sept 13, 2019, Monterrey, Mexico.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: L. Ma. 2019. Cold Plasma Technology for Feed Decontamination. Oral Presentation. Chinese Toxicology Society Feed Toxicology Committee Annual Meeting, Aug 22, 2019, Shanghai, China. Mexico Association for Food Protection Annual Meeting, Sept 13, 2019, Monterrey, Mexico.
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Diaz, C. 2019. Prevalence, molecular characterization, and inactivation of foodborne pathogens on native pecans. Ph.D. dissertation. Oklahoma State University.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Diaz, C., J. Diaz, C. Somoza, J. Cuellar, C. Timmons, K. Pai, and L. Ma. 2019. Decontamination of Salmonella enterica on low-moisture foods by cold atmospheric plasma. Oral presentation, International Association for Food Protection Annual Meeting, July 21-24, 2019. Louisville, Kentucky.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Diaz, C., J. Diaz, C. Somoza, J. Cuellar, C. Timmons, K. Pai, and L. Ma. 2019. Decontamination of Salmonella enterica on low-moisture foods by cold atmospheric plasma. Oral presentation, Robert Kerr Food & Agricultural Products Center Research Symposium, Feb 26, 2019, Stillwater OK.


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Academic research communities, fresh produce and food industries, and governmental regulatory officials Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided the opportunity for graduate students to learn and experiment with cold plasma technology which is considered a new promising approach for improving food safety. How have the results been disseminated to communities of interest?Research results have been disseminated to communities of interest by 1) presentations at international and national professional meetings 2) seminars at international and national institutions; 3) publications at peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?Optimization of the cold plasma device for decontamination a variety of produce including tree nuts, spices, and seeds. Also, opportunities for extending the application of cold plasma will be explored.

Impacts
What was accomplished under these goals? Postharvest decontamination treatment is a critical step in reducing food safety risk associated with minimally processed produce, such as fruit, vegetable, and tree nuts. However, current technologies based on chemical sanitizers (such as chlorine) not only have limited inactivation efficiency but also consumer a tremendous amount of water, a natural resource. The food industry is constantly on the look for new decontamination technology. Cold plasma, as a dry technology, has the capacity to inactivate microbes including foodborne pathogens on produce surface with minimum usage of water. Using our previously designed cold plasma device evaluation was conducted on the inactivation efficiency cold atmospheric plasma (CAP) on Salmonella enterica on in-shell pecans and black peppercorns. The results revealed that treatment time had a significant effect on the reduction of the pathogen on pecans and black peppercorns. On in-shell pecans, an average of 4.04-log CFU reduction was observed at all distances tested when CAP-treated for 10 minutes. Similarly, 3.63-log CFU reduction was achieved on black pepper at all distances tested when CAP-treated for 10 minutes. Moistening of pecans or black peppercorns prior to treatment achieved an additional 1-log reduction of Salmonella compared to the treatment without moistening.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: K. Pai, C. Timmons, K. Roehm, A. Ngo, S. S. Narayanan, A. Ramachandran, J. Jacob, L. Ma, and S. Madihally. 2018. Investigation of the roles of plasma species generated by surface dielectric barrier discharge. Scientific Reports. 8:16674. DOI: 10.1038/s41598-018-35166-0.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Diaz, C., C. Somoza, J. Cuellar, C. Timmons, K. Pai, and L. Ma. 2018. Decontamination of Salmonella enterica on low-moisture foods by cold atmospheric plasma. Poster presentation, Arkansas Association for Food Protection Annual Conference, Sept 17-20, 2018, Fayetteville, AR.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Diaz, C., C. Somoza, J. Cuellar, C. Timmons, K. Pai, and L. Ma. 2018. Inactivation of Salmonella enterica on in-shell pecans by cold atmospheric plasma. Oral presentation, International Association of Food Protection Annual Meeting, July 8-11, 2018, Salt Lake City, UT
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Diaz, C., J. Diaz, C. Somoza, J. Cuellar, C. Timmons, K. Pai, and L. Ma. 2018. Inactivation of Salmonella on in-shell pecans and black pepper by cold atmospheric plasma. Oral presentation, Robert Kerr Food & Agricultural Products Center Research Symposium, Feb 20, 2018, Stillwater OK.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Academic research communities, fresh produce and food industries, and governmental regulatory officials. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided the opportunity for the graduate students to learn and experiment with cold plasma technology which is considered a new promising approach for improving food safety. How have the results been disseminated to communities of interest?Research results have been disseminated to communities of interest by 1) presentations at international and national professional meetings 2) seminars at international and national institutions; 3) publications at peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?Optimization of the cold plasma device for decontamination a variety of produce including tree nuts, spices, and seeds. Also opportunities for extending the application of cold plasma will be explored.

Impacts
What was accomplished under these goals? Postharvest decontamination treatment is a critical step in reducing food safety risk associated with minimally processed produce, such as fruit, vegetable, and tree nuts.However, current technologies based on chemical sanitizers (such as chlorine) not only have limited inactivation efficiency but also consumer a tremendous amount of water, a natural resource.The food industry is constantly on the look for new decontamination technology.Cold plasma, as a dry technology, has the capacity to inactivate microbes including foodborne pathogens on produce surface with minimum usage of water.We have designed a novel cold plasma device for decontamination of raw produce.We have evaluated the effect of the arrangement of electrodes on the cold plasma flow and inactivation of foodborne pathogen Listeria monocytogenes.Further evaluation was conducted with additional major foodborne pathogens Salmonella enterica and Shiga toxin-producing E. coli.The results revealed that our unique design induced more turbulent and high velocity cold plasma flow which in turn resulted in higher killing efficiency of foodborne pathogens at longer distance than other design.About 3 log reduction of the pathogen was achieved on inoculated pecan in 5 min treatment. A patent application has been filed for the device.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Timmons, K. Pai, J. Jacob, G. Zhang, and L. Ma. 2017. Inactivation of Salmonella enterica, Shiga toxin-producing Escherichia coli, and Listeria monocytogenes by a novel surface discharge cold plasma design. Food Control. DOI: 10.1016/j.foodcont.2017.09.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Hu, L., L.M. Ma, S. Zheng, H. Wang, E. W. Brown, T. S. Hammack, and G. Zhang. 2017. Development of a novel Loop-mediated isothermal amplification (LAMP) assay for the detection of Salmonella ser. Enteritidis from egg products. Poultry Sci. DOI: 10.3382/ps/pew399
  • Type: Book Chapters Status: Published Year Published: 2017 Citation: Ma, M. L., Fletcher. J., Munford, J., Holt, J., and Leach, A. 2017. Decision Tool for Assessing the Likelihood of an Intentional Foodborne Illness Outbreak. In M.L. Gullino, J. Fletcher, J. Stack, and J. Mumford (Eds), Practical Tools for Plant and Food Biosecurity (pp179-208). New York, NY: Springer Publishing.
  • Type: Book Chapters Status: Published Year Published: 2017 Citation: Fletcher, J., Alpas, H., Henry, C., Ma, L. M., Robb, P., Soyer, Y. and Yeni, F. 2017. Foodborne Pathogens on Plants: Vulnerabilities, Risks, Infrastructure, and Future Priorities. In M.L. Gullino, J. Fletcher, J. Stack, and J. Mumford (Eds), Practical Tools for Plant and Food Biosecurity (pp61-76). New York, NY: Springer Publishing.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Academic research communities, fresh produce and food industries, and governmental regulatory officials Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?It has provided the opportunity for the graduate students to participate in scientific conferences. How have the results been disseminated to communities of interest?Research results have been disseminated to communities of interest by 1) presentations at international and national professional meetings 2) seminars at international and national institutions; 3) publications at peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?Continue the work and explore further opportunities.

Impacts
What was accomplished under these goals? The followings have been partially accomplished: 1) Nonthermal atmospheric plasma decontamination of foodborne pathogens has been conducted with glass coverslips and the results confirmed that the novel SDBD cold plasma actuator design can extend cold plasma's biocidal activity to distant surfaces; and 2) Elucidation of molecular mechanisms of human pathogen inactivation by cold plasma through RNA-seq analysis revealed a general decrease in stress responses which could be a result of rapid lipid peroxidation, cytosolic leakage, and cell lysis.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Timmons, C. E. Trees, E. M. Ribot, P. Gerner-Smidt, P. Lafon, S. Lm, and L. Ma. 2016. Multiple-locus variable-number tandem repeat analysis for strain discrimination of non-O157 Shiga toxin-producing Escherichia coli. J. Microbiol. Methods. 125: 70-80.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Timmons, C., K. Pai, and L. M. Ma. 2016. Elucidation of molecular mechanisms of foodborne pathogen inactivation by cold plasma through RNA-seq analysis. Poster presentation, International Association of Food Protection annual meeting, July 31-August 3, 2016, St. Louis, MS.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Hu, L., L.M. Ma, S. Zheng, H. Wang, E. W. Brown, T. S. Hammack, and G. Zhang. 2016. Evaluation of 3M Molecular Detection Assay Salmonella and ANSR Salmonella methods for Rapid Detection of Salmonella from Egg Products. American Society for Microbiology (ASM) 2016, June 16-20, Boston.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Hu, L., L.M. Ma, S. Zheng, T. S. Hammack, and G. Zhang. 2016. Development of a novel Loop-mediated Isothermal Amplification (LAMP) Assay for the Detection of Salmonella ser. Enteritidis. American Society for Microbiology (ASM) 2016, June 16-20, Boston.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Hu, L., L. M. Ma, S. Zheng, H. Wang, E. W. Brown, T. S. Hammack, and G. Zhang. 2016. Comparison of 3M Molecular Detection Assay (MDA) Salmonella and ANSR Salmonella methods with the FDA Bacteriological Analytical Manual (BAM) method for rapid detection of Salmonella from egg products. The International Poultry Scientific Forum. January 25-26, 2016, Atlanta, GA.
  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Timmons, C. 2016. Elucidation of the Molecular Mechanisms of Foodborne Human Pathogen Inactivation by Cold Atmospheric Plasma Through RNA-seq Analysis. (Doctoral). Oklahoma State University.
  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Pai K. K. 2016. Asymmetric Surface Dielectric Barrier Discharge as Novel Method for Biological Decontamination. (Doctoral). Oklahoma State University.