Source: UNIVERSITY OF CALIFORNIA, DAVIS submitted to
AN INTEGRATED APPROACH TO ELIMINATE CROSS-CONTAMINATION DURING WASHING, CONVEYING, HANDLING AND PACKAGING OF FRESH PRODUCE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
1005370
Grant No.
2015-68003-23411
Project No.
CA-D-FST-2282-CG
Proposal No.
2014-06154
Multistate No.
(N/A)
Program Code
A4131
Project Start Date
May 1, 2015
Project End Date
Apr 30, 2023
Grant Year
2019
Project Director
Nitin, N.
Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
Food Science and Technology
Non Technical Summary
Cross contamination of fresh produce during washing, conveying and handling is a critical risk factor that has been associated with major disease outbreaks. The proposed integrated project brings together unique, complementary and synergistic approaches to address this challenge. The project team consists of food microbiologists, engineers, food chemists and process modelers. This team will develop novel processes and technologies aimed at identifying and minimizing the risk of cross-contamination during produce washing, conveying and handling. To reduce the risk of cross-contamination during produce washing, the research plan will quantitatively measure and mathematically model the role of washing conditions on attachment of bacteria to fresh produce from wash water. Based on this fundamental understanding, the research will provide guidelines for the design of fresh produce washing equipment and the flow conditions during washing of produce. To determine optimal concentration of a selected sanitizer in wash water, the research plan will develop a novel process control sensor based on direct measurement of oxidative stress in bacteria. The threshold level of oxidative stress in bacteria will be quantified and correlated with reduction in microbial load in wash water. Success in this research will result in a unique process control tool to reduce the risk of cross contamination of fresh produce and enhance fundamental understanding of oxidative stress resistance of bacteria to sanitizers. To enable rapid detection of pathogens in wash water and fresh produce, the research plan will synergistically combine nanophotonics and bacteriophages to develop a novel point of use device. This approach is based on rapid amplification of bacteriophages upon specific targeting of pathogens and highly sensitive detection of amplified phages on a nanophotonic array. Success in this research will enable rapid detection of pathogens in wash water and produce samples without enrichment and extended culturing of bacteria. To reduce the risk of cross contamination during washing and handling, this research plan will develop an alternative sanitization technology using plasma treated water and validate its efficacy in reducing microbial load in wash water, while preserving the quality of fresh produce. Success in this research will lead to a novel processing technology to improve safety of fresh produce.To reduce the risk of cross contamination during conveying, handling and storage, this research will develop a rechargeable self-decontaminating functions on food contact materials, thus enabling continuous sanitation of food contact surfaces. Success in this research will reduce transfer of bacteria from surfaces to fresh produce. To enable integration of research with education, this project aims to develop a comprehensive educational program aimed at training current and future students in interdisciplinary topics related to food safety, water and surface chemistries, novel processing technologies and biosensors. For successful translation of research to industrial practice, this project will collaborate extensively with industrial partners for both validation and transfer of technologies. These collaborative efforts will be complemented by outreach plans to disseminate knowledge regarding food safety and novel technologies to current professionals in industry. In summary, success of the proposed project will have a significant impact in reducing the incidence of food borne illness resulting from cross-contamination of fresh produce during washing, conveying and handling operations. This impact will be realized based on development and commercialization of innovative technologies and education of current and future professionals.
Animal Health Component
0%
Research Effort Categories
Basic
60%
Applied
30%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7121499202030%
7124099110370%
Goals / Objectives
· Characterize the risk of cross-contamination of fresh produce as a function of flow conditions in a washer and optimize the washer design and process parameters using a combination of experimental and numerical simulation approaches to reduce the risk. · Develop innovative biosensing approaches to rapidly assess the microbial response to sanitation operations.· Develop a point of use biosensor for a rapid detection of bacterial pathogens in wash water· Evaluate novel sanitizers technologies based on plasma treated water for in-situ generation of free radicals in wash water and their comparison with conventional sanitizers on reducing microbial load and produce quality. · Engineer "self-regenerating antimicrobial coatings" for conveyor and storage containers to reduce the risk of cross contamination
Project Methods
1. To develop quantitative understanding of bacterial attachment to fresh produce during washing, the research methods will include standard microbial plate counting, optical imaging, mathematical modeling and statistical analysis. 2. For developing a process control to optimize concentration of sanitizers in wash water, the research approach will utilize magnetic, electronic and optical spectroscopy and imaging approaches. To improve sensitivity of these spectroscopy and imaging approaches, specific contrast media will also be developed that can accurately measure the intracellular oxidative stress in bacteria. The results of oxidative stress measurements will be correlated with reduction in microbial load. 3. To detect pathogens in wash water and fresh produce, the research approach is based on biochemically tagging of secondary phages, nanofabrication of photonic arrays, mathematical modeling and experimental validation of phage entrapment in nanophotonic wells and detection using the photonic arrays. 4. To develop an alternative sanitation approach, non-equilibrium discharge in water (moving or stationary) will be generated by applying 20 kV pulse (for ignition) and supplying 3 kV DC current (to sustain the arc) between two conducting pipes separated by a 2mm gap. The plasma activated water will be tested for washing fresh produce and the data will be analyzed using standard microbiological culturing methods and statistical analysis. 5. Rechargable antimicrobial coatings will be developed based on optimization of polymer design and engineering of chlorine binding monomers. These engineered materials will be tested using a combination of physical, chemical and microbiological testing methods. 6. For the education function to train current and future professional, the proposed research plan will use a combination of formal academic courses, professional workshops and practicum experiences.

Progress 05/01/15 to 04/30/23

Outputs
Target Audience:The target audiences reached by this project includes fresh produce processors, farmers, chemical sanitizer suppliers, fresh produce washing and handling equipment makers, produce marketing boards, diagnostic companies, plasma equipment manufacturers, regulatory agencies, academic faculty and researchers and undergraduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?In the final year of the project extension period, the project partially supported the training of two postdoctoral scholars. These scholars have now been placed in tenure-trackfaculty positions in the US. How have the results been disseminated to communities of interest?The results were disseminated through presentations at meetings, including national meetings for IFT, and IAFP, and intl meetings of food safety and hygiene, ANDPlasma. In addition, Prof. Nitin participated in extension and outreach workshops organized by the postharvest center at UC Davis. These workshops brought ~130-150 participants to the event. At these workshops, we shared our progress in developing novel sanitation and washing methods and provided a review of the current approaches and potential challenges in the fresh produce industry. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The report summarizes the technological advances to address the risk of cross-contamination of fresh produce: Produce washing is a critical control step for preventing cross-contamination. Our team using mathematical modeling and numerical modeling has demonstrated an optimum location for injecting chlorinein a flume used to wash fresh produce to achieve a more uniform distribution of free chlorine in the wash water. This can improve uniformity in chlorine distribution by several folds in a flume washer. In terms of product loading, it was shown thatwhen the distance between the two consecutive produce was less than fourtimes the major produce dimension, the shear washing efficiency of the plume was reduced. Scale up system based on GAT (gliding arc tornado) activated water was developed, and its efficiency in the washing of fresh produce, including romaine lettuce, kale, strawberries etc was evaluated. The GAT plasma-activated fresh produce washing system was scaled up to the level of 40 G of wash water, which is sufficient for initial commercial application. We designed, manufactured, and tested the GAT water treatment plasma system with power levels up to 3 kW. Plasma-activated water provided 2 log reduction of bacteria load on the surface of the fresh produce as well as complete suppression of the fresh produce cross contamination by sterilization of washing water. Recent observations of plasma-activated water (PAW)'s surfactant behavior suggest that the activation of water with non-equilibrium plasma can decrease the surface tension of the water. While the chemical behavior of PAW has been extensively analyzed, to the best of our knowledge, the physical properties of PAW have not been investigated. This suggested change to the surface tension also indicates that the addition of plasma can lead to changes in the physical properties of the water, knowledge of which can expand existing PAW applications and open new ones. In another line of inquiry, we evaluated whether SMD (surface micro discharges of plasma) exposure of lettuce, spinach and kale results in oxidative stress within the plant leaf and whether this stress upregulates the salicylic acid and jasmonic acid pathways to increase the phytochemical content of produce. Cold atmospheric plasma (CAP) is a surface modification technology that has shown extensive promise as a pathogen inactivation technology due to its production of multiple highly reactive products, including reactive oxygen and nitrogen species (RONS). RONS inactivate pathogens via oxidative damage to the cell membrane as well as DNA damage. However, this oxidative damage is not restricted to pathogenic organisms and can result in quality loss in the products treated with CAP. While investigating the interactions of plasma products on leafy greens, we found that plasma treatment triggers a stress response in plant tissue. Spinach, red leaf lettuce, and kale all significantly increased their ROS content following CAP treatment. However, significant differences were observed in flavonoid content in the three different species. After CAP treatment, flavonoid content in spinach leaves treated with 120 W CAP increased significantly (p<0.05), while the opposite effect was observed in kale where all treatments resulted in a significant reduction in flavonoid content. No significant difference in flavonoid content was observed in red leaf lettuce compared to control. Due to the complexity of plasma-generated species as a function of plasma generation conditions, dosimetry of cold atmospheric pressure plasma (CAPP) and plasma-activated water (PAW) is essential for the industrial application of this promising technology, including scale-up of the technology. We have developed a novel biosensing approach using DNA immobilized on a surface sensing pad as a surrogate to evaluate plasma dosimetry. Chemical changes in DNA induced upon exposure to plasma and plasma-activated water were characterized usinginfrared spectroscopy,and the data was analyzed using a machine learning algorithm to predict the decontamination effectiveness of CAPP and PAW. Chitosan-DNA films were developed and treated with CAPP or PAW. Changes in the spectral properties of DNA were characterized with Fourier-transform infrared spectroscopy (FTIR) and correlated to the dosage levels of CAPP and PAW and decontamination efficacy. Using the LightGBM algorithm, both plasma dosage and the inactivation efficacy against bacteria and biofilms were predicted with high accuracy (>89%) based on the spectral features of DNA. In summary, these results illustrate a novel approach for validating the decontamination efficacy ofplasma processing. To translate the halamine-based antimicrobial coatings to field applications to prevent cross-contamination, we have developed a novel approach that uses food-grade biopolymers as a coating material. The key features of these coatings include (a) the use of food-grade compositions to reduce the regulatory barriers; (b) a flexible coating approach that could be applied to a diversity of shapes and materials (knives and conveyor belts); (c) the ability to coat legacy equipment without any surface modifications, (d) ability for repeated applications. The key results demonstrate: Rapid and uniform coating formulations were developed using food-grade biopolymers, including beeswax, gelatin, gelatin/soy protein, and zein, and/or yeast-based microcarriers, including YCs and YCWPs for diverse food-contact and handling surfaces. The mechanical stability of the coating formulations was demonstrated in the simulated processing operations. Rapid inactivation of more than 5 log of inoculated (< 5 min) diverse pathogenic bacteria (E. coli O157:H7 and L. innocua) was demonstrated on diverse stainless steel (SS) and plastic surfaces (PP) in the presence of organic matter. SS and PP surfaces coated with the antimicrobial formulations effectively reduced the risk of cross-contamination of the fresh produce with hazardous bacteria in the simulated fresh produce-handing operation. In field testing, zein-based coating effectively reduced the microbial accumulation on the SS harvesting knife during lettuce harvesting/trimming operations and on the SS fruit sorting table during peach grading operations without affecting the quality of the fresh produce. The zein-based antimicrobial coating also showed strong antiviral activities against various types of viruses, including bacteriophages T4 and T7, and Tulane virus (a surrogate for human norovirus). This is highly promising since our coating can be applied to diverse abiotic surfaces and reduce cross-contamination of a broad spectrum of pathogenic viruses and bacteria. The zein-based antimicrobial coating showed strong potential in reducing the cross-contamination of Enterococcus faecium in dry products. It is noteworthy that our zein-based coating not only can work in a wet environment but also can work in a dry environment. We find this highly promising since there are limited disinfection methods that can be applied to the dry food handling environment.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Zhang, Huanle; Wisuthiphaet, Nicharee; Cui, Hemiao; Nitin, Nitin; Liu, Xin; Zhao, Qing; Spectroscopy Approaches for Food Safety Applications: Improving Data Efficiency Using Active Learning and Semi-supervised Learning, Frontiers in Artificial Intelligence,5,863261, 2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: El-Moghazy, Ahmed Y; Wisuthiphaet, Nicharee; Amaly, Noha; Nitin, Nitin; Enhanced sampling of bacteria and their biofilms from food contact surfaces with robust cationic modified swabs, Cellulose,29,8,4509-4524,2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Yi, Jiyoon; Leveau, Johan HJ; Nitin, Nitin; Role of multiscale leaf surface topography in antimicrobial efficacy of chlorine-based sanitizers, Journal of Food Engineering, 332,111118,2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Doh, Hansol; Nitin, Nitin; Gelatin-based rechargeable antibacterial hydrogel paint coating for reducing cross-contamination and biofilm formation on stainless steel, Food Control, 141,109113,2022.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Nguyen, Cuong Huu; Tikekar, Rohan V; Nitin, Nitin; Combination of high-frequency ultrasound with propyl gallate for enhancing inactivation of bacteria in water and apple juice, Innovative Food Science & Emerging Technologies, 82, 103149, 2022
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Cui, Hemiao; Wang, Qingyang; Rai, Rewa; Salvi, Deepti; Nitin, Nitin; DNA-based surrogates for the validation of microbial inactivation using cold atmospheric pressure plasma and plasma-activated water processing, Journal of Food Engineering,339, 111267,2023
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Kim, Yoonbin; Ma, Luyao; Huang, Kang; Nitin, Nitin; Bio-based antimicrobial compositions and sensing technologies to improve food safety Current Opinion in Biotechnology ,79,102871 2023
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: M Shaji, A Rabinovich, M Surace, C Sales, A Fridman, Physical Properties of Plasma-Activated Water, Plasma 6 (1), 45-57
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: J He, A Rabinovich, D Vainchtein, A Fridman, C Sales, MN Shneider, Effects of plasma on physical properties of water: nanocrystalline-to-amorphous phase transition and improving produce washing, Plasma 5 (4), 462-469
  • Type: Other Status: Published Year Published: 2023 Citation: J He, A Rabinovich, D Vainchtein, A Fridman, C Sales, M Shneider, Theory and modeling of nanocrystalline-amorphous transition in liquids, Drexel Univ., Philadelphia, PA (United States)


Progress 05/01/21 to 04/30/22

Outputs
Target Audience:Target audiences include: Fresh Produce Industry, Food Processing Industry, Academic and Industry Researchers, Regulatory Agencies, Graduate and Undergraduate students Changes/Problems:There were limitations in the recruitment of postdoc scholars due to visa processing delays during pandemic. This delayed some of the research efforts in this period. What opportunities for training and professional development has the project provided?The project during the last year has supported the training of 6 Ph.D. students, 6 postdoctoral researchers, and 5 undergraduate researchers. How have the results been disseminated to communities of interest?The results were disseminated through presentations at meetings, including national meetings forIFT, and IAFP, and intl meetings of food safety and hygiene, Plasmain S. Korea. In addition, Prof. Nitin participated in extension and outreach worships organized by the postharvest center at UC Davis. These workshops brought ~130-150 participants to the event. At these workshops, we shared our progress in developing novel sanitation and washing methods and provided a review of the current approaches and potential challenges in the fresh produce industry. The list of these events is described below: Innovations in Sanitizer Formulations and Process Validation for Fresh Produce Washing, Presenter, Postharvest Short Course, June, 2021, 130 Attendees. J Yi, N Nitin, Antimicrobial Food-Grade Coatings on Hydrophobic Plastics for Reducing Cross-Contamination of Fresh Produce, IAFP 2021. International Conference on Plasma Medicine, ICPM8, A.Fridman, Non Thermal Plasma for Application in Medicine and Fresh Produce Treatment, Seoul, South Korea, 2021. International Symposium on Plasma Bioscience ISPB10, A.Fridman, Washing of Fresh Produce using Plasma Activated Water, Seoul, South Korea, 2021. International Symposium on Plasma Bioscience ISPB11, A.Fridman, Atmospheric Pressure Plasma for Biological Applications, Seoul, South Korea, 2022. AI enabled innovations in food safety, N. Nitin, USDA, ARS, 2022. Biomaterials and biosensing for food safety, N.Nitin, UIUC, Food Science Department, 2022. Innovations in Biomaterials for food quality and safety applications, N. Nitin, Rutgers University, Food Science Department, 2021. Applications of AI in food safety applications in fresh produce, N. Nitin, Data Science symposium, LLNL, Nov, 2021 What do you plan to do during the next reporting period to accomplish the goals? Deployment of numerical models to both predict and improve decontamination of fresh produce. This work builds on our ongoing effort to develop novel sanitizers and their combination with numerical models. Ongoing work in dosimetry measurement is focused on translating measurements to characterize the decontamination process of fresh produce and food contact surfaces including multi-species biofilms using plasma processing. Evaluate translation of the sensing approaches to detect bacteria using field samples and assess portability of the sensing assays. These translational efforts are complemented by ongoing work on improving sensitivity of these pathogen detection assays Translation of atmospheric plasma systems to industrial applications through partnership with fresh produce industry and associated research programs such as Center for produce safety. Evaluate translation of antimicrobial coating during harvesting and postharvest handling. This research will be conducted through on-going partnership with fresh produce industry.

Impacts
What was accomplished under these goals? Characterize the risk of cross-contamination of fresh produce as a function of flow conditions in a washer and optimize the washer design and process parameters:The achievements in this period include: For an industrial scale flume washer, the effect of the ratio of fresh produce and recirculating water on bacteria inactivation was studied numerically. The influence of the locations of chlorine injection ports and multiple chlorine injection ports on resultant chlorine distribution in the flume washer was also investigated. The results showed that injecting chlorine from the side edges of the flume achieved a more uniform distribution of free chlorine in the wash water. It was found that lowmain-flow velocity in the flume with higher injection velocity gave a better distribution of free chlorine in the wash water. In an industrial scale flume washer, the effect of the distance between two adjacent spherical produce on the surface shear stress experienced by the produce was studied numerically. The downstream produce always experienced lower shear stress on the surface compared to the upstream produce when the distance between the two produce was less than four times the produce diameter. Developed numerical simulation models to demonstrate enhancement in efficacy for the inactivation of biofilms using bio-based antimicrobial delivery systems. These numerical models guided the selection of design parameters of these novel bio-based particles. The results of these numerical simulations were validated using experimental measurements. Develop innovative biosensing approaches to rapidly assess the microbial response to sanitation operations:Atmospheric plasma is an emerging technology with significant potential. However, the lack of dosimetry standards and process validation measurements significantly limits the industrial deployment and regulatory approval of this technology. To address this gap, our team has focused on developing a dosimetry sensor for atmospheric plasma processing using a combination of DNA based films and machine learning approaches. Due to complexity of plasma generated reactive species and variability in plasma composition as function of plasma generation condition, there is a need to develop process validation. This study aims to evaluate plasma interactions with DNA- based surrogate using infrared spectroscopy and a gradient boosting decision tree learning algorithm for data analysis to validate the antimicrobial effectiveness of CAPP and PAW. Chitosan-DNA films were developed and treated with CAPP and PAW respectively. Changes in the spectral properties of DNA was characterized with Fourier-transform infrared spectroscopy (FTIR) and correlated to the dosage levels of CAPP and PAW and microbial inactivation efficacy. Using the LightGBM algorithm, both plasma dosage and the inactivation efficacy against bacteria and biofilms were predicted with high accuracy (> 89%) based on changes in the spectral features of DNA. In summary, these results illustrate a novel approach for validating the microbialactivity of plasma processing. Develop a point of use biosensor for a rapid detection of bacterial pathogens in wash water:The significant achievements were Development of a colorimetric biosensing approach that enables sensitive (10 CFU/ml) detection of target bacteria in food systems using a simple visual assay and/or quantitative colorimetric measurements. This approach uses a genetically modified phage and a colorimetric substrate to generate the color change upon phage infection of a target bacteria. One of the unique findings of this research was the sensitivity of this approach to detect bacteria without the need of isolating bacteria from food samples. This isolation step has been identified as one of the key barriers in the field. A highly sensitive electrochemical sensing platform was developed for the detection ofEscherichia coli(E. coli) on fresh leafy vegetables. The sensing platform was assembled based on utilizing genetically engineered bacteriophage T7 encoding with phoA gene as a biorecognition element that can trigger alkaline phosphatase enzyme over-expression upon the target bacterial infection. The alkaline phosphatase over-expression was followed electrochemically using a single-wall carbon nanotube-modified screen-printed electrode. The assembled bacteriophage-based electrochemical sensor is able to provide rapid and accurate detection and quantification of pathogenicE. colion spinach leaves at a concentration range of 1-104 CFU mL−1 within 1 h after a pre-enrichment (4-5 hours). Moreover, the developed biosensor exhibited high specificity toward theE. coliin the presence of other common food bacterial contaminants. On going efforts are to develop novel biosensing strategies and biosensor technologies to address the challenges of sensitivity, sample background and biological variations in field samples. Evaluate novel sanitizers technologies based on plasma treated water for in- situ generation of free radicals in wash water and their comparison with conventional sanitizers on reducing microbial load and produce quality:In the area of reducing microbial load on fresh produce, the significant achievements include: GAT (gliding arc tornado) activated water has been proved efficient in washing of fresh produce, including romaine lettuce, kale, strawberries etc. Plasma activated water provided 2 log reduction of bacteria load on the surface of the fresh produce as well as completely suppression of the fresh produce cross contamination bysterilization of washing water. No visible changes in plasma treated produce were observed. Wash time in most experiments was 1 min. It is important that the achieved produce disinfection and suppression of cross contamination has been demonstrated not only in clean wash water but in water with significant organic load corresponding to commercial application conditions. The GAT plasma-activated fresh produce washing system was scaled up to the level of 40 G of wash water, which is sufficient for initial commercial application. We designed, manufactured and tested the GAT water treatment plasma system with water flow rate through the plasmatron increased to 10 ml/min and power level up to 3 kW. Food safety efficacy was tested with washing of romaine lattice and confirmed above mentioned results from bench scale experiments. In our ongoing efforts in the area of synergistic processing, we have developed two complementary solutions. In our first approach, we successfully combined a novel lipid-modified derivative of vitamin C with mild heat to achieve more than 5 log inactivation of inoculated microbes on model fresh produce systems. With mild heat level used in this study did not significantly influence thecolor and texture of the product. This solution can be easily adapted in the food service industry to reduce the incidence of food-borne illness in the industry. The ongoing efforts are aimed at translating these systems to industrial applications through partnership with the fresh produce industry and associated research programs such as the Center for produce safety. 5. Engineer "self-regenerating antimicrobial coatings" for conveyor and storage containers to reduce the risk of cross contamination:The key results in this period include: Develop halamine food-grade polymeric beads and biopolymer microgels to enhance decontamination of fresh produce and inactivation of biofilms. These approaches address the unmet need to enhance the stability and delivery of chlorine to target bacteria in the presence of organic content. Develop halamine and zwitterion-based antimicrobial and antifouling membranes for the inactivation of viruses and bacterial cells. This approach was demonstrated to be highly effective for the treatment of simulated wash water and can aid in the treatment of recirculating wash water.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: K Huang, J Yi, GM Young, N Nitin, Cell-based carriers incorporated antimicrobial coatings on diverse food contact surfaces for preventing cross-contamination of fresh produce, Food Control 134, 108700, 2022.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: 2. Y Chang, J Bai, H Yu, X Yang, PS Chang, N Nitin, Synergistic inactivation of Listeria and E. coli using a combination of erythorbyl laurate and mild heating and its application in decontamination of peas as a model fresh produce, Food Microbiology 102, 103869, 2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: H Doh, Y Kim, N Nitin, Development of a food grade sanitizer delivery system with chlorine loaded gelatin microgels for enhanced binding and inactivation of biofilms, Food Research International, 111026, 2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: J Tan, J Yi, X Yang, H Lee, N Nitin, M Karwe, Distribution of chlorine sanitizer in a flume tank: Numerical predictions and experimental validation, LWT 155, 112888, 2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: AY El-Moghazy, N Wisuthiphaet, X Yang, G Sun, N Nitin, Electrochemical biosensor based on genetically engineered bacteriophage T7 for rapid detection of Escherichia coli on fresh produce, Food Control, 108811 , 2022
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: 7. Jiyoon Yi, Kang Huang, Nitin Nitin, Modeling bioaffinity?based targeted delivery of antimicrobials to Escherichia coli biofilms using yeast microparticles. Part I: Model development and numerical simulation, Biotechnology and Bioengineering 119, 2022.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: 8. J Yi, K Huang, N Nitin, Modeling bioaffinity?based targeted delivery of antimicrobials to Escherichia coli biofilms using yeast microparticles. Part II: Parameter evaluation and validation, Biotechnology and bioengineering 119 (1), 247-256, 2022.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: H. Cui, R Ovissipour, X Yang, N Nitin, Machine learning analysis of phage oxidation for rapid verification of wash water sanitation, Postharvest Biology and Technology 181, 111654, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: 11. K Huang, X Yang, Y Ma, G Sun, N Nitin, Incorporation of Antimicrobial Bio-Based Carriers onto Poly(vinyl alcohol-co-ethylene) Surface for Enhanced Antimicrobial Activity, ACS Applied Materials & Interfaces 13 (30), 36275-36285, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: J Yi, K Huang, Y Ma, G Sun, GM Young, N Nitin, Antimicrobial N-Halamine incorporated Poly (Vinyl alcohol-co-ethylene) films for reducing cross-contamination of fresh produce, Food Control 124, 107880, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: 13. Y Wu, Y Si, S Liu, N Nitin, G Sun, Chlorine Rechargeable Halamine Biocidal Alginate/Polyacrylamide Hydrogel Beads for Improved Sanitization of Fresh Produce, Journal of Agricultural and Food Chemistry 69 (45), 13323-13330, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: N Wisuthiphaet, X Yang, GM Young, N Nitin, Application of Engineered Bacteriophage T7 in the Detection of Bacteria in Food Matrices, Frontiers in microbiology, 2188, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Y Chang, J Bai, H Yu, PS Chang, N Nitin, Synergistic Inactivation of Bacteria Using a Combination of Erythorbyl Laurate and UV Type-A Light Treatment, Frontiers in microbiology, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: P Tang, AY El-Moghazy, B Ji, N Nitin, G Sun, Unique posture of rose Bengal for fabricating personal protective equipment with enhanced daylight-induced biocidal efficiency, Materials advances 2 (11), 3569-3578, 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: 21. Juzhong Tan and Mukund V. Karwe, Inactivation and Removal of Enterobacter aerogenes Biofilm in a Model Piping System using Plasma-activated Water (PAW), accepted for publication in Innovative Food Science and Emerging Technologies, 69, March 2021
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: 20. Juzhong Tan, Bin Zhou, Yaguang Luo, and Mukund V. Karwe, "Numerical Simulation and Experimental Validation of Bacterial Detachment using a Spherical Produce Model in an Industrial-scale Flume Washer," Food Control, Vol. 30, December, 2021.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: 18. M.Larussi, S.Bekeschaus, A.Fridman ea. Low temperature plasma for biology hygiene and medicine, IEEE transactions on radiation and plasma medical sciences, 12/14 2021.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: A.Rabinovich, G.Nirenberg, S.Kocagoz, A.Fridman, M.Surace, C.Sales, Scaling up of non thermal plasma systems for industrial applications, Plasma Chemistry and Plasma Processing, 42 (1), 35-50, 2022
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Y Ma, N Wisuthiphaet, N Nitin, G Sun, A Novel N-Halamine Biocidal Nanofibrous Membrane for Chlorine Rechargeable Rapid Water Disinfection Applications, ACS Applied Materials & Interfaces 13 (34), 41056-41065 2021


Progress 05/01/20 to 04/30/21

Outputs
Target Audience:Target audiences include: Fresh Produce Industry, Food Processing Industry, Academic and Industry Researchers, Regulatory Agencies, Graduate and Undergraduate students Changes/Problems:The COVID-19 situation has resulted in some delays in both research and outreach and education activities. Due to reduced accessiblity to research labs for most part of the year and limited availability of postdoctoral researcher candidates, we had to delay recruitment of two postdocs for the project. In addition, graduate student research was also impacted by the Covid-19 constraints. We do not anticipate change in overall scope of our goals, however additional time may be required for these goals. Despite the constraints, the team has made significant progress as reflected by the publications in leading journals, filing of patents, extension and outreach activities and also efforts for commercialization of technologies. What opportunities for training and professional development has the project provided?This project has supported the research training of 6 graduate student and 6 postdoctoral scholars during this review period. Through this interdisciplinary training, these researchers are engaged in both laboratory science and outreach activities. In addition, the interactions among the team members have generated significant degree of cross-disciplinary collaborative research. Through industry outreach activities the trainees have received significant exposure to the "real" needs of the industry and also a perspective on the potential pathways for translation of their research towards novel solutions. This project has also supported the educational training of industry participants as described in the outreach activities. How have the results been disseminated to communities of interest?UC Davis, Drexel, and UMD team members attended various conferences such as- IFT Annual Meeting 2020, IAFP Annual Meeting 2020 and PD meeting, and a number of plasma conferences and workshops. The team members participated in various outreach activities despite Covid-19 constraints. Dr. Nitin developed and offered two extension workshop sessions focused on food safety, wash water sanitation and wash equipment design during the pre-cut postharvest workshop and postharvest fresh produce workshop organized by the postharvest center. These sessions were attended by over 100 industrial participants from various sections of fresh produce industry in the US as well asinternational participants. The workshop sessions were evaluated by diverse participants and received greater than 4.5 rating out of 5.0 for most of the categories developedby the external evaluators for these workshops. In addition, one of the technologies developed by Dr. Nitin's lab was licensed by an early stage start up company that has received SBIR funding from both USDA and NSF. Through licensing of this technology and its development, Dr. Nitin has been engaged with diverse group of stakeholders to evaluate industrial the application of this antimicrobial technology. What do you plan to do during the next reporting period to accomplish the goals?For this no-cost extension period, the goals are to: 1. Complete the modeling efforts for a washing process of fresh produce 2. Develop and validation the combination of biological surrogates, spectroscopic analysis and machine learning for predicting plasma dosimetry 3. Advance developments of synergistic processing of fresh produce to improve food safety of food contact surfaces 4. Evalaute the combination of virtual reality and numerical simulation for developing online training

Impacts
What was accomplished under these goals? Characterize the risk of cross-contamination of fresh produce as a function of flow conditions in a washer and optimize the washer design and process parameters using a combination of experimental and numerical simulation approaches to reduce the risk:In this area, we conducted numerical simulation and experiments to investigate the effect of inter produce spacing during the washing process in an industrial flume. Using spherical produce models (40 mm diameter), we experimentally evaluated the effect of center-to-center distance on the efficacy of bacterial detachment from the produce models. Using COMSOL® Multiphysics we numerically simulated the fluid flow in the flume containing spherical produce models submerged in the wash water and calculated the surface shear stress distribution on the produce models. We were able to show that - a) varying the center-to-center distance between produce models from 40 mm to 200 mm increased the average shear stress on the downstream produce models from 264 mPa to 469 mPa, b) the shear stress on the produce models was not significantly different from each other when the distance between the upstream and downstream produce models was at least five times the diameter of the produce, and c) increasing center-to-center distance between produce models increased the number of bacteria that detached from the surface of the downstream produce models, which was consistent with the predicted higher shear stress on the downstream produce model at larger distances. Develop innovative biosensing approaches to rapidly assess the microbial response to sanitation operations: In this area, we have made significant advances with integration of machine learning approaches and biological surrogates to rapidly assess the microbial response to sanitation operations. Using this combination, our results show that the Fourier Transform infrared (FTIR) spectroscopy can detect changes in biochemical properties of biological surrogates induced by chlorine and peroxyacetic acid (PAA). The Gradient Boosting algorithm was employed to develop predictive model using the spectroscopy data to predict both the sanitizer concentration levels andEscherichia coliO157:H7 inactivation. The machine learning model predicted both the effective sanitizer concentration level andbacterialreduction with receiver operating characteristic curve (ROC) values between 0.86 and 0.93operations. We are currently developing these approaches to assess dosimetry of plasma treated water and direct plasma. Develop a point of use biosensor for a rapid detection of bacterial pathogens in wash water:Rapid detection of bacterial pathogens is a critical unmet need for both food and environmental samples such as irrigation water. As a part of the Food safety Modernization Act (FSMA), The Produce Safety rule has established several requirements for testing for the presence of genericEscherichia coliin water, but the current method available for testing (EPA M1603) demands specified multiple colony verification and highly trained personnel to perform these tests. The purpose of the study was to assess a phage induced bacterial lysis using quantitative image analysis to achieve rapid detection ofE.coliat low concentrations within 8 hours. This study aimed to develop a simple yet highly sensitive and specific approach to detect target bacteria in complex matrices. In the study,E.colicells were first enriched in tryptic soy broth (TSB), followed by T7 phage induced lysis, concentration, staining and fluorescent imaging. Image analysis was conducted including image pre-processing, image segmentation and quantitatively analysis of cellular morphological features (area, eccentricity and full width at half maximum). Challenge experiments using realistic matrices, including simulated fresh produce wash water, coconut water and spinach wash water, demonstrated the method can be applied for use in situations that occur in food processing facilities. The results indicatedE.colicells that are lysed by T7 phages demonstrated significantly (P < 0.05) higher extracellular DNA release, altered cellular shape (from rod to circular) and diffused fluorescent signal intensity. Using this biosensing strategy, a sensitivity to detectEscherichia coliat 10 CFU/ml within 8 hours was achieved, both in laboratory medium and in complex matrices. The proposed phage based biosensing strategy enables rapid detection of bacteria and is applicable to analysis of food systems. Furthermore, the steps involved in this assay can be automated to enable detection of target bacteria in food facilities without extensive resources. On-going efforts are being made to further develop devices that enable rapid detection of bacteria at point of use facility. Evaluate novel sanitizers technologies based on plasma treated water for in-situ generation of free radicals in wash water and their comparison with conventional sanitizers on reducing microbial load and produce quality: In the area of reducing microbial load on fresh produce, our results demonstrate plasma activated water can reduce about 2 log CFU/ gof the inoculated bacteria on the surface of romaine lettuce. These results were conducted using pilot scale plasma activated water generator at Drexel University. These results support the overall goal of scale-up of plasma related technologies and their application for the treatment of fresh produce. In addition, we also observed that direct plasma treatment of fresh produce triggered astress response within spinach leaves and further studies are on-going to examinewhether this increased stress results in elevated levels of phytochemicals.In addition to plasma-based antimicrobials, we have continued our discovery and translation of light activated antimicrobial technologies. In this period, we investigated and demonstrated potential of plant-based compounds to enable synergistic inactivation of pathogens including antibiotic resistant bacteria. The results of these studies illustrate that broad class cinnamic acid derivates such as ferulic acid provides rapid inactivation of bacteria in the presence of light. This is to our knowledge the first study that demonstrates the potential of broad class of food grade compounds with synergistic activity. Engineer "self-regenerating antimicrobial coatings" for conveyor and storage containers to reduce the risk of cross contamination: In this area, we have successfully developed and validatedcombination of antimicrobial and antifouling properties using both polymeric and non-woven surfaces. The validation tests were done using both bacterial and viral targets with and without organic content. All these surfaces also demonstrated rechargeable antimicrobial properties. In addition, we also developed photo-activated material antimicrobial coatings that combine photoinactivation with antifouling functions.

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Ma, Yue, Zheng Zhang, Nitin Nitin, and Gang Sun. "Integration of photo-induced biocidal and hydrophilic antifouling functions on nanofibrous membranes with demonstrated reduction of biofilm formation." Journal of colloid and interface science 578 (2020): 779-787.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Zhang, Zheng, Ahmed Y. El-Moghazy, Nicharee Wisuthiphaet, Nitin Nitin, Diego Castillo, Brian G. Murphy, and Gang Sun. "Daylight-Induced Antibacterial and Antiviral Nanofibrous Membranes Containing Vitamin K Derivatives for Personal Protective Equipment." ACS Applied Materials & Interfaces 12, no. 44 (2020): 49416-49430
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Wu, Yuehan, Yang Si, Shilin Liu, Nitin Nitin, and Gang Sun. "Chlorine Rechargeable Halamine Biocidal Alginate/Polyacrylamide Hydrogel Beads for Improved Sanitization of Fresh Produce." Journal of Agricultural and Food Chemistry (2021).
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Ma, Yue, Jiyoon Yi, Bofeng Pan, Nitin Nitin, and Gang Sun. "Chlorine Rechargeable Biocidal N-Halamine Nanofibrous Membranes Incorporated with Bifunctional Zwitterionic Polymers for Efficient Water Disinfection Applications." ACS Applied Materials & Interfaces 12, no. 45 (2020): 51057-51068.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Ma, Yue, Nicharee Wisuthiphaet, Hunter Bolt, Nitin Nitin, Qinghua Zhao, Dong Wang, Behnam Pourdeyhimi, Pierre Grondin, and Gang Sun. "N-Halamine Polypropylene Nonwoven Fabrics with Rechargeable Antibacterial and Antiviral Functions for Medical Applications." ACS Biomaterials Science & Engineering (2021).
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Rapid detection of Escherichia coli using bacteriophage-induced lysis and image analysis, X Yang, N Wisuthiphaet, GM Young, N Nitin, PloS one 15 (6), e0233853
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Inactivation of foodborne pathogens based on synergistic effects of ultrasound and natural compounds during fresh produce washing H Zhang, S Wang, K Goon, A Gilbert, CN Huu, M Walsh, N Nitin, S Wrenn, R. Tikekar, Ultrasonics sonochemistry 64, 104983
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Role of contaminated organic particles in cross-contamination of fresh produce during washing and sanitation, K Huang, Y Tian, J Tan, D Salvi, M Karwe, N Nitin Postharvest Biology and Technology 168, 111283
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Fabrication of Biomimetic Spinach Leaves and the Role of Surface Microstructure on Decontamination Efficacy during the Washing Process J Yi, K Huang, N Nitin, IAFP 2020
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Incorporation of Antimicrobial Bio-based Carriers onto Plastic Surface for Enhanced Antimicrobial Activity, K Huang, X Yang, Y Ma, G Sun, N Nitin IAFP 2020
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Rapid Detection of Pathogenic Bacteria Using Engineered Bacteriophage N Wisuthiphaet, X Yang, G Young, N Nitin, IAFP 2020
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Gilbert A. and Tikekar R. Understanding the Effect of Cold Atmospheric Plasma on Leafy Greens and Escherichia Coli, IFT20 Annual Meeting, Chicago, IL. (Online) Placed 2 nd in Fruits and Vegetables division student competition.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: A signal-on electrochemical aptasensor based on silanized cellulose nanofibers for rapid point-of-use detection of ochratoxin A, AY El-Moghazy, N Amaly, G Istamboulie, N Nitin, G Sun, Microchimica Acta 187 (9), 1-11
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Alexander Fridman, Alexander Rabinovich, Danil Dobrynin "Plasma Simulated NO Generation, Plasma Production of Fertilizers, Plasma Stimulation of Plant Growth", Invited Talk, International Symposium on Plasma Applications, ISPlasma-10, Nagoya (virtual), Japan, March 2021
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Alexander Fridman, Alexander Rabinovich "Plasma Misting in Agriculture", Invited Presentation, International Workshop on Plasma for Agriculture, IWOPA-4, Greifswald, Germany, (virtual), March, 2021.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Targeted Photodynamic Treatment of Bacterial Biofilms Using Curcumin Encapsulated in Cells and Cell Wall Particles, F Dou, K Huang, N Nitin, ACS Applied Bio Materials 4 (1), 514-522
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Screening of antimicrobial synergism between phenolic acids derivatives and UV-A light radiation, EF de Oliveira, X Yang, N Basnayake, CN Huu, L Wang, R Tikekar, N. Nitin, Journal of Photochemistry and Photobiology B: Biology 214, 112081
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Tan, J., Zhou, B., Luo, Y. and Karwe, M.V., 2021. Numerical Simulation and Experimental Validation of Bacterial Detachment using a Spherical Produce Model in an Industrial-scale Flume Washer. Food Control, https://doi.org/10.1016/j.foodcont.2021.108300
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Antimicrobial N-Halamine incorporated Poly (Vinyl alcohol-co-ethylene) films for reducing cross-contamination of fresh produce, J Yi, K Huang, Y Ma, G Sun, GM Young, N Nitin, Food Control 124, 107880
  • Type: Theses/Dissertations Status: Published Year Published: 2021 Citation: Novel Antimicrobial Compositions and Mathematical Models for Reducing Microbial Contamination of Fresh Produce and Food Contact Surfaces, Ji Yoon Yi, PhD Dissertation


Progress 05/01/19 to 04/30/20

Outputs
Target Audience:Target audiences include: Fresh Produce Industry, Food Processing Industry, Academic and Industry Researchers, Regulatory Agencies, Graduate and Undergraduate students Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has supported the research training of 11 graduate students, 7 undergraduates and 8 postdoctoral scholars. Through this interdisciplinary training, these researchers are engaged in both laboratory science and outreach activities. In addition, the interactions among the team members have generated significant degree of cross-disciplinary collaborative research. Through industry outreach activities the trainees have received significant exposure to the "real" needs of the industry and also a perspective on the potential pathways for translation of their research towards novel solutions. This project has also supported the educational training of over 133 graduate students (30 students in year 1, 30 students in year 2; 18 students in year 3; 30 students in year 4; 25 students in year 5) in science communication through a novel course focused on science communication for researchers. How have the results been disseminated to communities of interest?Rutgers, UC Davis, Drexel, and UMD team members attended various conferences such as- IFT Annual Meeting 2019, IAFP Annual Meeting 2019 and PD meeting, Project IAB Meeting, and a number of plasma conferences and workshops. The team members participated in various outreach activities such as guest lecture (2019) in Food Microbiology course at Rutgers where Dr. Karwe talked about applications of cold plasma and surface modifications to reduce cross contamination in produce washing. Audience: undergraduate food science students (40). Dr. Nitin also developed and offered a graduate course on food safety engineering. This course focuses on various thermodynamic and kinetic analysis of microbial adhesion and cross-contamination. In addition, the course also evaluates the thermodynamics basis of advanced food safety processing technologies. Our team has also been actively engaged in transfer of knowledge to stakeholders. The results of our research were presented at two extension workshops organized by the postharvest center at UC Davis. These presentations targeted over 85 industrial participants. In addition, Dr. Nitin also presented at the training workshop for FDA and state food safety inspectors on the emerging food safety technologies including light, ozone, high pressure and plasma processing. This event was attended by 30 inspectors. What do you plan to do during the next reporting period to accomplish the goals? Aim 1: From the numerical simulation, validate the results of pilot scale studies with a commercial scale washing systems. Complete models for inactivation of bacteria in suspension and plant systems and bacterial biofilms using conventional and particle based sanitizers. Aims 2 and 3: Advance validation of edible surrogate markers for predicting efficacy of sanitation on surfaces including food contact surfaces, fresh produce and in wash water. Continuing integration of bacterial detection approaches with electrochemical detection technologies to develop portable detection devices. Aim 4: Continuing efforts to scale-up non-oxidative GlidArc treatment system to 10 ml/min (current 0.1 ml/min) flow rate and provide experimental validation with E.coli, Salmonella, and Listeria in wash water. Scale-up oxidative DBD microdroplet treatment system to 1 m3 or 1,000 liters (currently 100 liters) and provide experimental validation of this system with E.coli, Salmonella, and Listeria on spinach, kale, lettuce, strawberries, and fresh cut baby carrots. ?Aim 5: Evaluate scale up of light or mild heat mediated inactivation of bacteria on fresh produce for a food service application. Industrial translation of antimicrobial surface technologies to demonstrate effectiveness in preventing fresh produce cross-contamination.

Impacts
What was accomplished under these goals? The overall research goal of this project is to reduce/eliminate cross-contamination of fresh produce during a washing process. To achieve this goal, we are developing an integrated approach based on combination of understanding the influence of mechanical aspects of wash systems, developing state of the art biosensing approaches for process validation, and developing novel sanitization technologies such as cold plasma, light activated sanitizers, and self-regenerating antimicrobial materials for food contact surfaces during processing. With this overall goal, the key accomplishments of this project during the period from May, 2019 to Jan, 2020 are categorized into: (a) innovations in antimicrobial and sanitization technologies for fresh produce industry; (b) development of process control and biosensing approaches; and (c) understanding and developing innovative washing solutions. Innovations in antimicrobial and sanitization technologies for fresh produce industry: In this area, our team has developed novel antimicrobial materials; discovered and evaluated translation of synergistic antimicrobial solutions based on food grade compounds and advanced the application and translation of plasma processing technologies. The key achievements are: Combination of bio-based antimicrobial particles with biopolymer to form food- grade antimicrobial compositions that (a) prevent cross-contamination even after extended exposure to contaminating produce; (b) prevent biofilm formation and (c) provide rapid inactivation of surface inoculated for an extended period of time. The potential of these materials to form coatings on diverse food contact surfaces makes this innovation highly relevant for improving safety of fresh produce. This innovation has also resulted in a patent application. Composite halamine materials formed using a combination of fibers and polymers. The presence of both textile fiber and polymer coating enables significant improvement in the total halamine concentration and its accessibility for the inactivation of bacteria compared to polymer films alone. This material demonstrated significant potential to enhance the rate of microbial inactivation and can be integrated with existing applications using polymer surfaces. Combination of anti-fouling and chlorine rechargeable halamine biocidal films and coatings as liners for totes and bins to reduce x-contamination of fresh produce from food contact surface with a high risk of microbial contamination. The combined functionality reduces the fraction of microbes attaching irreversibly to the surface as well as biofilm formation on the surface. Continued investigation on the daylight-induced biocidal chemicals for sanitization of produce with focuses on edible chemicals and preparation of the daylight-induced biocidal polymeric materials with potential applications as fresh produce packaging films and wraps. These results are significant as these materials can be recharged by sunlight and can maintain antimicrobial activity for an extended time. Continued discovery of synergistic interactions between diverse food grade compounds and mild physical stresses such as mild heat and light. In this reporting period we discovered: (a) bioactives that can synergistically inactivate pathogenic microbes in the presence of high protein content during spray drying; (b) bioactives to rapid synergistic inactivation of pathogenic bacteria on diverse fresh produce and (c) bioactive compound that can inactivate diverse biofilms using visible and sunlight. These results are being validated for multi-species biofilms. These results are significant as the levels of inactivation on fresh produce surface, biofilms and protein rich matrixes are significantly higher than achieved with the current sanitation methods. Furthermore, studies were also conducted to evaluate the ability of microbes to adapt to these mild synergistic treatments and potentially develop resistance against these treatments. Discovered and demonstrated that short and medium chain fatty acids are effective in decontaminating produce wash water and reduce the risk of cross-contamination. This result is significant as typically organic acids have been used in combination with chlorine to improve antimicrobial activity. These results may provide an alternative to the use fatty acids to improve decontamination of fresh produce and reduce cross-contamination. For the plasma mediated sanitation of wash water and fresh produce, the key achievements during this period include: (a) 1) scale up to industrial-scale prototype level the dielectric barrier discharge (microsecond DBD) plasma misting system and gliding arc water treatment plasma. We started building DBD microdroplet treatment system for produce disinfection with capacity 1 m3 or 1,000 liters (currently 100 liters). We started designing the GlidArc water treatment plasma system with water flow rate through the plasmatron increased to 10 ml/min (current 0.1 ml/min). Once the system will be ready (1st Q 2020) we'll provide experimental validation of this system with major bacteria of interest for produce safety such as E.coli, or Salmonella, and Listeria on spinach, kale, lettuce, strawberries. In the area of plasma based decontamination technologies, we also explored the antimicrobial effect of water-free surface micro-discharge plasma (SMD) treatment. With ambient air as working gas and 1 min of treatment time, effective bacterial inactivation with >2 logarithmic cycles of E. coli O157:H7 reduction was observed in media and spinach leaves. Because the SMD reactor can be easily scaled up and integrated in existing food processing lines, the SMD is suitable for large?scale raw food processing in centralized facilities. In addition, because this disinfection approach only requires air and electricity, it appears promising for application by end consumers to raw foods. We also characterized the effect of SMD treatment on the bacterial cell morphology of E. coli O157:H7. The key accomplishments for the development of process control and biosensing approaches are: For validation of sanitation, we advanced our "cell mimetic" approach to predict inactivation efficacy of both planktonic cells and biofilms in response to sanitizer. This approach combines development of biomaterial based edible surrogates for assessment of sanitation efficacy combined with spectroscopy and data analytics include machine learning approaches to characterize complex spectroscopic signatures. This innovation has resulted in filing of a patent application in this review period. For detection of bacteria in fresh produce industry, we have developed a comprehensive approach using bacteriophages and advanced imaging and detection technologies. Using this combination, we can detection 10 CFU/ml in 6 hours on fresh produce without prior isolation of bacteria from fresh produce. The detection technologies include: nanoscale electrochemical sensors and the imaging technologies include simple colorimetric sensors as well as fluorescence imaging and quantification. The key accomplishment in quantitative understanding of the washing process are: At pilot plant scale, using COMSOL® Multiphysics numerical simulation model was conducted on a flume, we were able to show - a) higher chlorine injection velocity from the bottom of flume and slower main flow velocity resulted in more uniform distribution of free chlorine and b) Injecting chlorine perpendicular to the sides of the flume washer could achieve more uniform chlorine distribution in the flume compared to injecting chlorine perpendicular to the bottom of the flume.

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: J Yi, K Huang, GM Young, N Nitin, Quantitative analysis and influences of contact dynamics on bacterial cross-contamination from contaminated fresh produce, Journal of Food Engineering 270, 109771, 2020
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: N Wisuthiphaet, X Yang, GM Young, N Nitin, Rapid detection of Escherichia coli in beverages using genetically engineered bacteriophage T7, AMB Express 9 (1), 55, 4, 2019
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: X Yang, R Rai, CN Huu, N Nitin, Synergistic Antimicrobial Activity by Light or Thermal Treatment and Lauric Arginate: Membrane Damage and Oxidative Stress, Applied and environmental microbiology 85 (17), e01033-19, 2019
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: 4. EF de Oliveira, CN Huu, K Stepanian, A Cossu, N Nitin, Enhanced bacterial inactivation in apple juice by synergistic interactions between phenolic acids and mild food processing technologies, Innovative Food Science & Emerging Technologies, 102186, 2019.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: 5. Y Ma, J Li, Y Si, K Huang, N Nitin, G Sun, Rechargeable Antibacterial N-halamine Films with Antifouling Function for Food Packaging Applications, ACS applied materials & interfaces, 4, 2019.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: K Huang, F Dou, N Nitin, Bio-based Sanitizer Delivery System for Improved Sanitation of Bacterial and Fungal Biofilms, ACS applied materials & interfaces, 2019
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: 7. L Tilton, G Das, X Yang, N Wisuthiphaet, IM Kennedy, N Nitin, Nanophotonic Device in Combination with Bacteriophages for Enhancing Detection Sensitivity of Escherichia coli in Simulated Wash Water, Analytical Letters, 1-11, 2019.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: J Cheng, Q Chen, Z Qiao, K Chen, G Fridman, H Ji, A Colorimetric Method for Comparison of Oxidative Strength of DBD Plasma, Sensors and Actuators Reports, 2019
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Z Wang, Q Chen, Y Wei, AA Fridman, G Fridman, HF Ji , Chemistry of Air, N 2, and O 2 Reverse Vortex Gliding Arc Plasma System - Plasma Medicine, 2019
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wang Q.; Buchanan R.; Tikekar R. (2019). Evaluation of adaptive response in E. coli O157:H7 to UV light and gallic acid based antimicrobial treatments. Food Control
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: 11. Luan P.; Bastarrachea L.; Gilbert A; Tikekar R.; Oehrlein G. (2019). Decontamination of raw produce by surface micro-discharge (SMD) and the evaluation of its damage to cellular components. Plasma Processes and Polymers. 16(5), e1800193
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Zhang H. ; Dolan H.; Ding Q.; Wang S.; Tikekar R. (2019). Antimicrobial action of octanoic acid against Escherichia coli O157:H7 during washing of baby spinach and grape tomatoes. Food Research International
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: 13. Ding Q.; Tikekar R. (2019). The synergistic antimicrobial effect of a simultaneous UV-A light and propyl paraben (4-Hydroxybenzoic acid propyl ester) treatment and its application in washing spinach leaves. Journal of Food Process Engineering.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sherman-Woods R.; Tikekar R. (2019). Decontamination of irrigation water using a combined sand filtration and UV-C light treatment. Journal of Food Safety. Published online ahead of print. https://doi.org/10.1111/jfs.12744
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Zhang, Z., Si, Y. and Sun, G., (2019). Photoactivities of Vitamin K Derivatives and Potential Applications as Daylight-Activated Antimicrobial Agents. ACS Sustainable Chemistry & Engineering, 7(22), pp.18493-18504. 2019.


Progress 05/01/18 to 04/30/19

Outputs
Target Audience:The project directly engages students (both undergraduate and graduate) as well as postdoctoral researchers in research activities. During this period 7 undergraduates, 11 graduate students, 8 postdoctoral scholars received training through participation in this project. This project has also supported the educational training of 30 students in science communication through a novel course focused on science communication for researchers. The project has led to development of a SEOP (science education outreach program) section focused on food safety at UC Davis. The team members participated in various outreach activities such as guest lecture (2018) in Food Microbiology course at Rutgers by Dr. Mukund Karwe where Dr. Karwe talked about applications of cold plasma and surface modifications to reduce cross contamination in produce washing. Audience: undergraduate food science students (40). Peer Researchers: The projects team engages peer researchers through publications (17 publications), patents (2 patent applications and one provisional) and several presentations at national and international meetings. In addition, team has been actively engaged in developing collaborative proposals within the team as well as with other peer researchers to expand the research aimed at improving food safety of fresh produce Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has supported the research training of 11 graduate students, 7 undergraduates and 8 postdoctoral scholars. Through this interdisciplinary training, these researchers are engaged in both laboratory science and outreach activities. In addition, the interactions among the team members have generated significant degree of cross-disciplinary collaborative research. Through industry outreach activities the trainees have received significant exposure to the "real" needs of the industry and also a perspective on the potential pathways for translation of their research towards novel solutions. This project has also supported the educational training of over 108 graduate students (30 students in year 1, 30 students in year 2; 18 students in year 3; 30 students in year 4) in science communication through a novel course focused on science communication for researchers. The project has led to development of a SEOP (science education outreach program) section focused on food safety. Rutgers, UC Davis, Drexel, and UMD team members attended various conferences such as- IFT Annual Meeting 2018, IAFP Annual Meeting 2018 and PD meeting, Project IAB Meeting, and a number of plasma conferences and workshops. The team members participated in various outreach activities such as guest lecture (2018) in Food Microbiology course at Rutgers by Dr. Mukund Karwe where Dr. Karwe talked about applications of cold plasma and surface modifications to reduce cross contamination in produce washing. Audience: undergraduate food science students (40) and over five extension workshops focused on fresh produce and food safety by Dr. Tikekar at Univ. of Maryland. How have the results been disseminated to communities of interest?The results were disseminated through research publications, presentations, workshops, lectures and patent applications. What do you plan to do during the next reporting period to accomplish the goals?? These plans are aimed at (a) reducing risk of x-contamination; (b) inactivation of pathogen bacteria if present on a fresh produce and (c) provide tools and methods for the industry to validate sanitation processes and avoid potential recalls due to x-contamination. With these overall goals, our interdisciplinary team is evaluating the mechanics of produce washing and removal of bacteria, developing of sensors to improve validation of sanitation process, advanced non-thermal approaches to enhance inactivation of pathogenic bacteria on fresh produce surface and materials to limit x-contamination of fresh produce from food contact surfaces. Based on this comprehensive approach, this integrated project addresses the un-met needs of the produce industry and also enables approaches that can be applied broadly across diverse sectors of food industry. The specific goals for the Aim 1 (UC Davis and Rutgers) Investigate chlorine injection strategies and flow conditions by COMSOL® to achieve more uniform chlorine distribution. Validate injected chlorine distribution in an industrial scale flume washer at UC Davis. From the numerical simulation, calculate shear stress distribution on moving objects in an industrial scale flume washer. Develop models for inactivation of bacteria in suspension and plant systems and bacterial biofilms using conventional and particle based sanitizers. Key Deliverables: Quantitative information on range of shear experienced by produce in a flume washer, and the effect of flow conditions and sanitizer concentration on microbial detachment and cross contamination. The specific goals for the Aims 2 and 3 are (UC Davis): The research goals for Year 5 are: Development and validation of edible surrogate markers for predicting efficacy of sanitation on surfaces including fresh produce and in wash water. This effort with expand on the earlier research on cell based biosensing approaches and is selected based on the feedback from the advisory board. Simple and scalable approaches to detect bacteria in irrigation streams, wash water and from food contact surfaces using bacteriophages Integrate these detection approaches with electrochemical detection technologies to develop portable detection devices. The plans for the Aim 4 are (Drexel, UC Davis, and University of Maryland): The research goals for Plasma Team in the Year 5 are: In 2019, we plan to continue both research directions and expand them both vertically and horizontally: 1) scale up to larger volume of fresh produce treatment; and 2) expand to different fresh produce types and additional bacteria. Specific plans for 2019 are: Scale-up non-oxidative GlidArc treatment system to 10 ml/min (current 0.1 ml/min) flow rate and provide experimental validation with E.coli, Salmonella, and Listeria in wash water. Scale-up oxidative DBD microdroplet treatment system to 1 m3 or 1,000 liters (currently 100 liters) and provide experimental validation of this system with E.coli, Salmonella, and Listeria on spinach, kale, lettuce, strawberries, and fresh cut baby carrots. For novel antimicrobials (both synergistic antimicrobials and novel delivery approaches) the specific goals are: Expand utilization of spent materials for synergistic antimicrobial activity applications Evaluate scale up of light or mild heat mediated inactivation of bacteria on fresh produce for a food service application. Develop low cost high affinity bio-particles to specifically target bacteria and their biofilms and deliver high payloads of antimicrobial. The specific goals for the Aim 5 are (UC Davis): The specific goals for the "rechargeable antimicrobial coatings" are • Development of antifouling and chlorine rechargeable halamine biocidal films as liners for totes and bins to reduce x-contamination of fresh produce from food contact surface with a high risk of microbial contamination. • Development of chlorine rechargeable halamine porous soft materials as fruit wraps for prolonged storage time and reduced wastes. • Continued investigation on the daylight-induced biocidal chemicals for sanitization of produce with focuses on edible chemicals. • Preparation of the daylight-induced biocidal polymeric materials with potential applications as fresh produce packaging films and wraps. .Training: UC Davis Team: The UC Davis team will have a team of postdoctoral research fellows Drs. Rewa Rai, Jaewoo Bai, Yoonjee Chang Xu Yang, Kang Huang and graduate students Erick Falcao, Yue Ma, Zhang Zheng, Ji-Yoon Ji, Nicharee Wisuthiphaet, Cuong Huu working on Aims 1, 2-3 and 5. Two of these graduate students are supported through fellowships from various national and international organizations. This research team will closely collaborate with research team at Rutgers (Dr, JuzhongTan) for the Aim 1 of this project, Drexel University (PhD student: Pietro Ranieri; MS: 2 students MaharshiTrivedi,VishalManjunatha and 1 research technician: Mykola Kovalenko; Co-op students: 3 students--Gebski, Eric Bruce Hilal, SabrinJohn, and Eric W and University of Maryland a new PhD student) and Dr. Hongchao Zhang (postdoc) for the Aim 4 of this project. The detailed description of the annual commitment for these postdoctoral fellows and students is described in our budget justification document.

Impacts
What was accomplished under these goals? The key accomplishments of this project are summarized in terms of (a) innovations in antimicrobial and sanitization technologies for fresh produce industry; (b) development of process control and biosensing approaches; and (c) understanding and developing innovative washing solutions. Innovations in antimicrobial and sanitization technologies for fresh produce industry: In this area, our team has developed novel antimicrobial materials; discovered and evaluated translation of synergistic antimicrobial solutions based on food grade compounds and advanced the application and translation of plasma processing technologies. The key achievements are: Development of antifouling and chlorine rechargeable halamine biocidal films and coatings as liners for totes and bins to reduce x-contamination of fresh produce from food contact surface with a high risk of microbial contamination. This is motivated by our findings that surface x-contamination is a major food safety risk during handling and processing of fresh produce. The results are highly significant as some of these materials and coatings can also reduce microbial load on fresh produce and eliminate risk of x-contamination over an extended period of time. Developed novel particle based sanitizers that can address limitations of conventional chlorine based sanitizers during washing of fresh produce. The results of this research illustrated that fundamentally activity of conventional sanitizers are limited by transport processes. These novel particle based sanitizers can achieve 5 orders of magnitude improvement in inactivation of bacteria compared to conventional formulations. These results are highly significant as these results can address the unmet need for the fresh produce industry to achieve effective sanitation of fresh produce during washing. Continued investigation on the daylight-induced biocidal chemicals for sanitization of produce with focuses on edible chemicals and preparation of the daylight-induced biocidal polymeric materials with potential applications as fresh produce packaging films and wraps. These results are significant as these materials can be recharged by sunlight and can maintain antimicrobial activity for an extended time. Continued discovery of synergistic interactions between diverse food grade compounds and mild physical stresses such as mild heat and light. In this reporting we illustrated that bioactives extract from spent materials can result in inactivation of 3-4 log of inoculated model pathogenic bacteria on diverse fresh produce including lettuce, spinach and tomatoes. These results are significant as the levels of inactivation on fresh produce surface are significantly higher than achieved with the current sanitation methods including chlorine and the potential to use spent materials for inactivation further reduces the economic barriers to utilize these bioactive extracts for food safety applications Discovered and demonstrated that short and medium chain fatty acids are effective in decontaminating produce wash water and reduce the risk of cross-contamination. This result is significant as typically organic acids have been used in combination with chlorine to improve antimicrobial activity. These results may provide an alternative to the use fatty acids to improve decontamination of fresh produce and reduce cross-contamination. Discovery of oxidative and non-oxidative cold-plasma-based mechanisms of direct fresh produce disinfection during transportation, storage, and handling; and indirect disinfection of fresh produce processing fluids. Using the plasma mister approach, we demonstrated 8-log reduction of E.coli on Petri dishes and 4-log reduction of E.coli on the surface of diverse produce in a 100- liter refrigerated storage unit. The results illustrate that plasma system may be scaled up for a grocery store refrigerators or transportation system and can enhance inactivation of bacteria on model fresh produce. The key accomplishments for the development of process control and biosensing approaches are: For validation of sanitation, we developed a "cell mimetic" approach to assess the response of sanitizer based on spectroscopic analysis. In our published report, we demonstrated the potential of DNA as an edible surrogate for assessment of sanitation efficacy including predicting the free chlorine concentration and inactivation of bacteria. In addition to DNA based approach, we have also evaluated various cellular enzymes and anti-oxidative small molecules to predict sanitation efficacy. Our results have resulted in identification of specific enzymes and design of anti-oxidative encapsulated system to predict sanitation efficacy. Overall, these results are significant as they provide culture-independent assessment of sanitation using edible surrogate markers. For detection of bacteria in fresh produce industry, we have developed two complementary approaches, these approaches provide assessment of specific bacteria based on changes in morphological features of cells induced by phages as well as colorimetric and fluorescence detection using phages. The unique aspects of these approaches is the ability to detect low counts 10-100 cfu/ml in less than 6 hours using simple tools. Thus, the potential to translate these solutions to industrial applications is significant. The key accomplishment in quantitative understanding of the washing process are: At laboratory scale setup, using COMSOL® Multiphysics numerical simulation model and experiments we were able to show - a) Using recirculating chlorinated water to wash fresh produce did not have significant difference in reducing bacteria cross contamination compared to non-recirculating water, b) Organic particles in wash water increased the shear stress induced by fluid flow, and c) Bacterial attachment can take place in presence of shear stress, and d) Injecting chlorine from the sides of the flume washer can achieve more uniform chlorine distribution in the flume. For an industrial scale flume washer, the effect of the ratio of fresh and recirculating water on bacteria inactivation was studied numerically. Using recirculating chlorinated water to wash fresh produce had similar bacteria inactivation compares to using only fresh water after 3 min of washing. The influence of the locations of chlorine injection ports on final chlorine distribution in the flume washer was also investigated. The results showed that injecting chlorine from the side edges of the flume water achieved more uniform distribution of free chlorine in the wash water. Using a simple and an innovative approach, we have assessed the role of leaf- leaf and leaf- surface contact in x-contamination of fresh produce. The results suggest rapid transfer of bacteria from contaminated to non-contaminated leaves, but the % transfer of bacteria from leaf-leaf contact is significantly less than contact of a leaf with a contaminated food contact surface. This result suggests that the risk of x-contamination from contaminated food contact surface may be higher than leaf- leaf transfer.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: M Ovissipour, R Rai, N Nitin, DNA-based surrogate indicator for sanitation verification and predict inactivation of Escherichia coli O157: H7 using vibrational spectroscopy (FTIR),Food Control 100, 67-77, 2019
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: K Huang, N Nitin,Antimicrobial Particle Based Novel Sanitizer for Enhanced Decontamination of Fresh Produce, Appl. Environ. Microbiol., AEM. 02599-18
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: EF de Oliveira, R Tikekar, N Nitin, Combination of aerosolized curcumin and UV-A light for the inactivation of bacteria on fresh produce surfaces, Food Research International 114, 133-139
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: A Cossu, K Huang, M Cossu, RV Tikekar, N Nitin, Fog, phenolic acids and UV-A light irradiation: A new antimicrobial treatment for decontamination of fresh produce, Food microbiology 76, 204-208
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: EL Vonasek, AH Choi, J Sanchez Jr, N Nitin, Incorporating Phage Therapy into WPI Dip Coatings for Applications on Fresh Whole and Cut Fruit and Vegetable Surfaces, Journal of food science 83 (7), 1871-1879
  • Type: Journal Articles Status: Submitted Year Published: 2018 Citation: K Huang, S Wrenn, R Tikekar, N Nitin, Efficacy of decontamination and a reduced risk of cross-contamination during ultrasound-assisted washing of fresh produce Journal of Food Engineering 224, 95-104
  • Type: Journal Articles Status: Submitted Year Published: 2018 Citation: Y Si, Z Zhang, W Wu, Q Fu, K Huang, N Nitin, B Ding, G Sun, Daylight-driven rechargeable antibacterial and antiviral nanofibrous membranes for bioprotective applications, Science advances 4 (3), eaar5931
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: K Huang, Y Tian, D Salvi, M Karwe, N Nitin, Influence of Exposure Time, Shear Stress, and Surfactants on Detachment of Escherichia coli O157:H7 from Fresh Lettuce Leaf Surfaces During Washing Process, Food and Bioprocess Technology 11 (3), 621-633
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: EF de Oliveira, JV Tosati, RV Tikekar, AR Monteiro, N Nitin, Antimicrobial activity of curcumin in combination with light against Escherichia coli O157: H7 and Listeria innocua: Applications for fresh produce sanitation, Postharvest biology and technology 137, 86-94
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: JV Tosati, EF de Oliveira, JV Oliveira, N Nitin, AR Monteiro, Light-activated antimicrobial activity of turmeric residue edible coatings against cross-contamination of Listeria innocua on sausages, Food Control
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2018 Citation: Wang A.; Leong W.-F.; Elias R.; Tikekar R.* (2019) UV-C irradiated gallic acid exhibits enhanced 1 antimicrobial activity via generation of reactive oxidative species and quinone. Food Chemistry (In press)
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: " Microsecond-Pulsed Dielectric Barrier Discharge Plasma-Treated Mist for Inactivation of Escherichia coli In Vitro, P Ranieri, G McGovern, H Tse, A Fulmer, M Kovalenko, G Nirenberg, ... IEEE Transactions on Plasma Science 47 (1), 395-402
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: White paper on the future of plasma science in environment, for gas conversion and agriculture, R Brandenburg, A Bogaerts, W Bongers, A Fridman, G Fridman, BR Locke, ..., Plasma Processes and Polymers, 1700238
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: " Effects of cold plasma treatments on spot-inoculated Escherichia coli O157: H7 and quality of baby kale (Brassica oleracea) leaves, U Shah, P Ranieri, Y Zhou, CL Schauer, V Miller, G Fridman, JK Sekhon, Innovative Food Science & Emerging Technologies
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Polymerization of D-Ribose in Dielectric Barrier Discharge Plasma, Y Li, R Atif, K Chen, J Cheng, Q Chen, Z Qiao, G Fridman, A Fridman, ..., Plasma 1 (1), 144-149
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Optimization of Short-Pulsed Dielectric Barrier Discharge for In-Package Disinfection, P Ranieri, A Mannsberger, C Liu, A Suarez, A Huynh, V Miller, ..., Plasma Medicine 8 (2)


Progress 05/01/17 to 04/30/18

Outputs
Target Audience:The target audiences for our project are fresh produce industry, academicresearchers, government research laboratories Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has supported the research training of11 gradaute students, 4undergraduatesand8 postdoctoral scholars. Through this interdisciplinary training, these researchers are engaged in both laboratory science and out reach activities. In addition, the interactions among the team members have generated significant degree of cross-discplinary collaborative research. Through industry outreach activities the trainees have received significant exposure to the "real" needs of the industry and also a perspective on the potential pathways for translation of their research towards novel solutions. This project has also supported the educational training of over60 graduate students (30students in year 1, 30 students in year 2)in science communication through a novel course focused on science communication for researhers. The project has led to development of a SEOP (science education outreach program) section focused on food safety. Rutgers,UC Davis, Drexel and UMDteam members attended various conferences such as- IFT Annual Meeting 2017, IAFP Annual Meeting 2017 and PD meeting, Project IAB Meeting. The team members participated in various outreach activities such as Undergraduate Food Safety Introduction Session and Elementary School Food Safety Education at Rutgers University, Plasma Engineering Course at Drexel University and Food Safety Engineering graduate course at UC Davis. One M.S. student from Rutgers participated in two poster competitions and won 3rd place in NYIFT Student Poster Competition and 2nd Place in the Food Engineering session at the IFT Annual Meeting in Las Vegas. A team of undergraduate students at UC Davis developed a video to illustrate risk of cross-contamination in fresh produce industry as a part of our outreach and educationaleffort for public. In addition to these activities, following professional development opportunities were provided to broader scientific community and students including middle school students: 1. Organized and hosted the first International Workshop on Plasma Agriculture (IWOPA) at Drexel University, May 15th to May 20th, 2016. Researchers and commercial teams from over 20 countries participated. 2. Organizing the second IWOPA for March 2018 in Nagoya, Japan 3. Incorporating a special Agriculture section in the 7th International Conference on Plasma Medicine (ICPM7), to be hosted by Drexel University, June 17th to June 22nd, 2018. 4. Incorporating a special Agriculture lecture for summer school associated with ICPM7. 5. Salvi, D., Karwe M. V., Ponnusamy, C. (2017) Food Safety Education. Math/science day at Wicoff Elementary School, Plainsboro, NJ, March 17, 2017 6. Salvi, D., Ponnusamy, C. (2017) Food Safety Research and Education. Summer Freshman Workshop at Rutgers University, July 2017 How have the results been disseminated to communities of interest?The results were disseminated to academia and industry researchersthrough journal publications, presentations at conferences and meetings including meetings withindustry advisory board. The results were alsodisseminated to general public through outreach activities such as Picnic day at UCDavisvisit to middle school in NJ, and development of a video by undergradaute students at UC Davis highlighting food safety issues in the food industry and the steps taken by the industry to minimize food safety risks. What do you plan to do during the next reporting period to accomplish the goals? Year 4 Research Plan: These plans are aimed at (a) reducing risk of x-contamination; (b) inactivation of pathogen bacteria if present on a fresh produce and (c) provide tools and methods for the industry to validate sanitation processes and avoid potential recalls due to x-contamination. With these overall goals, our interdisciplinary team is evaluating the mechanics of produce washing and removal of bacteria, developing of sensors to improve validation of sanitation process, advanced non-thermal approaches to enhance inactivation of pathogenic bacteria on fresh produce surface and materials to limit x-contamination of fresh produce from food contact surfaces. Based on this comprehensive approach, this integrated project addresses the un-met needs of the produce industry and also enables approaches that can be applied broadly across diverse sectors of food industry. The specific goals for the Aim 1 (UC Davis and Rutgers) Study the effect of organic load on chlorine transport during produce washing in an industrial scale flume washer. Calculate shear stress distribution on produce surface during produce washing in an industrial scale flume washer and characterize the force of adhesion of microbes to fresh produce Couple fluid flow, chlorine transport, and microbial attachment-detachment kinetics to predict sanitizer and microbial load on produce surface and wash water in an industrial scale flume washer. The specific goals for the Aim 2 and 3 are (UC Davis): Based on the findings of Years 1-3, the research goals for Year 4 are: Testing and validation of bacterial cell mimicking biosensor that can simultaneously assess lipid damage, thiol oxidation and DNA damage induced by sanitizers. This effort with expand on the cell based biosensing approaches developed in years 2 and 3 and is selected based on the feedback from the advisory board. Integration of cell free biosensors with fresh produce and their validations during a washing approach Develop cell free biosensor to assess x-contamination using engineered cell mimicking carrier Simple and scalable approach to detect bacteria in irrigation streams, wash water and from food contact surfaces The plans for the Aim 4 are (Drexel, UC Davis, Univ of Maryland): Based on the findings of Years 1, 2, and 3, research goals for Year 4 are: Continue optimization of plasma systems for produce disinfection: Produce disinfection by direct plasma treatment; Produce disinfection by plasma-treated mist; and Produce disinfection by washing with plasma-treated water. Validate range of antimicrobial properties of these systems. Together with UC Davis validate oxidative properties of all three plasma systems. Analyze specific input of all individual plasma parameters to the sterilization mechanism in each specific condition: Effect of long-living plasma-generated species; Effect of short-living plasma-generated species; and Effect of non-chemical plasma-generated species (ultraviolet radiation, pulsed electric field, shockwaves, etc). For the synergistic combination of antimicrobial compounds and mild physical stress the specific goals are: Evaluate scale up of light mediated inactivation of bacteria on fresh produce for a food service application Discover mechanisms for synergistic activity of the compounds with mild physical stress The specific goals for the Aim 5 are (UC Davis): Based on the results for Years 1-3, the specific goals for the "rechargeable antimicrobial coatings" is Translation of antimicrobial rechargeable films in developing antimicrobial liners for totes and bins to reduce x-contamination of fresh produce from food contact surface with a high risk of microbial contamination Modify antimicrobial rechargeable materials to combine non-fouling and antimicrobial properties Continued development of the green daylight-induced biocidal polymeric materials for sanitization of produce.

Impacts
What was accomplished under these goals? The overall research goal of this project is to reduce/eliminate cross-contamination of fresh produce during a washing process. To achieve this goal, we are developing an integrated approach based on combination of understanding the influence of mechanical aspects of wash systems, developing state of the art biosensing approaches for process validation and novel sanitization technologies such as plasma and light activated sanitizers and self-generating antimicrobial materials for food contact surfaces during processing. With this overall goal the key accomplishments of this project were: Using a combination of numerical simulation and experimental approaches we demonstrated that increased shear stress results in enhanced removal of bacteria, although the removal efficiency is limited to 2 log of bacteria (99% removal of bacteria) with extended washing (20 minutes) under high shear with sanitizer or 2-3 log using the combination of ultrasound and sanitizer. This result is significant for the design of wash systems for fresh produce as removal of spoilage and pathogenic microbes during washing is critical for food safety and extending shelf life of fresh produce. Further studies are on-going to measure the force of adhesion of bacteria on fresh produce. The presence of contaminated organic particles enhances the risk of x-contamination of produce, although these particles also enhance the shear stress on the surface of fresh produce.This result is significant as processors can develop steps to remove suspended particles from the wash water and may reduce the risk of x-contamination During washing of multiple fresh produce samples such as melons or cantaloupes, the results of numerical simulation illustrate that downstream produce experience less shear as compared to upstream produce samples due to shielding of the produce by upstream produce. This result has influence on the throughput of fresh produce in a wash system. Using a simple and an innovative approach, we have assessed the role of leaf- leaf contact in x-contamination of fresh produce. The results suggest rapid transfer of bacteria from contaminated to non-contaminated leaves, but the % transfer of bacteria from leaf-leaf contact is significantly less than contact of a leaf with a contaminated food contact surface. This result suggests that the risk of x-contamination from contaminated food contact surface may be higher than leaf- leaf transfer. To aid in validation of sanitation process for food industry, our team has developed two complementary approaches. The first approach is based on using labeled bacteria for rapid detection of the reaction between bacteria and sanitizer and resulting inactivation of bacteria using ESR spectroscopy (Election spin resonance). This method can be adapted to any surrogate bacteria and provides rapid on site validation of sanitation. In a second approach for validation of sanitation, we are developing a "cell mimetic" approach to assess the response of sanitizer using a visual read-out. In this cell mimetic approach, we have evaluated various cellular enzymes, DNA and antioxidative small molecules to predict sanitation efficacy. Our results have resulted in identification of specific enzymes and design of antioxidative encapsulated system to predict sanitation efficacy. Optimization of the direct dielectric barrier discharge plasma treatment system, plasma misting system and forward vortex gliding arc plasmatron with flow-through sprayer nozzles. Using barrier discharge plasma, we demonstrated removal of most spores from bread surface inside of a double bagging plastic. Using the plasma mister approach, we demonstrated 9-log reduction of E.coli on Petri dishes and 4-log reduction of E.coli on surface of a baby carrot stored in a 100- liter refrigeration unit. The results illustrate that plasma system may be scaled up for a grocery store refrigerators or transportation system and can enhance inactivation of bacteria on model fresh produce. We designed and built 200-liter water recirculation system with a flow rate of up to 50 ml/min through plasma. Initial resting shows ~1 log reduction per hour of operation and further optimization of plasma parameters is ongoing. This pilot scale system can handle large volume of wash water. Performed comparative studies of plasma-treated water versus common anti-microbial additives, such as acetic acid, peracetic acid, hydrogen peroxide, asorbic acid, ethanol, and others. Analyzing properties of the plasma-treated water, such as pH, H2O2, ONOO*, NO3-, NO2-, etc concentration and antimicrobial properties. We are using these as indicators for the most appropriate plasma regimes to inactivate pathogens rapidly but with minimal energy cost and no damage to fresh produce. Evaluation of "self-regenerating antimicrobial coatings and membranes" in rapid and complete inactivation of bacteria with organic load and also biofilms. Development of "chlorine refreshable and reusable biocidal beads" for produce sanitization. These biocidal beads have shown remarkable potential to inactivate microbes on fresh produce surface with short incubation time, significantly better than conventional chlorine based sanitizers. Demonstration of "daylight-activation and storage antibacterial materials", a green sanitizer, for rapid inactivation of foodborne bacterial. This discovery has a potential to develop activatable antimicrobial materials. Demonstrated that synergistic interactions between diverse phenolic compounds (gallic acid, benzoic acid, propyl gallate, curcumin, lactic acid) and mild physical stresses such as heat and UV/vis light can result in inactivation of 3-4 log of inoculated model pathogenic bacteria on diverse fresh produce including lettuce, spinach and tomatoes. Developed a fluorescence based techniques to measure intracellular bacterial pH, uptake of phenolic compounds by bacterial cells and their effect on microbial inactivation.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Non-Equilibrium Plasma Decontamination of E. Coli O157:H7 RifR Using Triple-Jet Double-Dielectric Barrier Discharge Water Misting System, Haley Patel, Lige Zhang, Amogh Sharma, Yuyuan Zhou, Anh Huynh, Mykola Kovalenko, Alexander Fridman, Vandana Miller, Gregory Fridman, Plasma Medicine journal, Special Issue on Plasma Agriculture, 2017
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Liquid-Phase Plasma Chemistry on Transitional Gliding Arc Plasma Treatment of Biofluids, Zhengduo Wang, Qiang Chen, Yen Wei, Hai-Feng Ji, Alexander Fridman, Greg Fridman, Plasma Chemistry and Plasma Processes, 2017
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Yang Si, Jiaying Li, Cunyi Zhao, Yue Deng, Yue Ma, Dong Wang, Gang Sun, Biocidal and Rechargeable N-Halamine Nanofibrous Membranes for Highly Efficient Water Disinfection, ACS Biomater. Sci. Eng., 2017, 3 (5), pp 854862 DOI: 10.1021/acsbiomaterials.7b00111
  • Type: Journal Articles Status: Accepted Year Published: 2018 Citation: Yang Si, Zheng Zhang, Wanrong Wu, Qiuxia Fu, Kang Huang, Nitin Nitin, Bin Ding, Gang Sun, Daylight-driven rechargeable antibacterial and antivirus nanofibrous membranes for bio-protective applications, Science Advances, accepted.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: EF de Oliveira, JV Tosati, RV Tikekar, AR Monteiro, N. Nitin*, Antimicrobial activity of curcumin in combination with light against Escherichia coli O157: H7 and Listeria innocua: Applications for fresh produce sanitation, Postharvest Biology and Technology, 2018
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: JV Tosati, EF de Oliveira, JV Oliveira, N. Nitin, AR Monteiro Light-activated antimicrobial activity of turmeric residue edible coatings against cross-contamination of Listeria innocua on sausages, Food Control, 2018.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: EF de Oliveira, A Cossu, RV Tikekar, N Nitin*, Enhanced Antimicrobial Activity Based on a Synergistic Combination of Sub-Lethal Levels of Stresses Induced by UV-A Light and Organic Acids, Applied and Environmental Microbiology, 00383-17, 2017
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: K Huang, N Nitin*, Enhanced removal of Escherichia coli O157: H7 and Listeria innocua from fresh lettuce leaves using surfactants during simulated washing, Food Control, 2017.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: K Huang, S Wrenn, R Tikekar, N Nitin*, Efficacy of decontamination and a reduced risk of cross-contamination during ultrasound-assisted washing of fresh produce, Journal of Food Engineering, 2017.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: A Cossu, Y Si, G Sun, N Nitin*, Antibiofilm Effect of Poly (Vinyl Alcohol-co-Ethylene) Halamine Film against Listeria innocua and Escherichia coli O157: H7, Applied and environmental microbiology, 2017 (highlighted by American Society of Microbiology and USDA-NIFA).
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: A Cossu, F Dou, GM Young, N Nitin*, Biomarkers of oxidative damage in bacteria for the assessment of sanitation efficacy in lettuce wash water, Applied Microbiology and Biotechnology, 2017.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: K. Huang, Y. Tian, D. Salvi, M.V. Karwe, and N. Nitin (2017). Influence of exposure time, shear stress, and surfactants on detachment of Escherichia coli O157:H7 from fresh lettuce leaf surface during washing process. Food and Bioprocess Technology. https://doi.org/10.1007/s11947-017-2038-5
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Salvi, D. (2017). Understand Produce Contamination. CEP Magazine- An AIChE Publication, May 2017 Issue, pp. 33-39.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Wang Q.; De Oliveira E.; Alborzi S.; Bastarrachea L.; Tikekar R. (2017). On mechanism behind UV-A light enhanced antibacterial activity of gallic acid and propyl gallate against Escherichia coli O157:H7. Scientific Reports. 7:8325.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Ding Q.; Alborzi S. ^; Bastarrachea L.; Tikekar R. (2018). Novel sanitization approach based on synergistic action of UV-A light and benzoic acid: Inactivation mechanism and a potential application in washing fresh produce. Food Microbiology. 72, 39-54.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mechanisms of Biocidal Activity of Dielectric Barrier Discharge Air Jet with Misting, K. Patel, A. Suarez, A. Mannsberger, H. Patel, M. Kovalenko, A. Fridman, V. Miller, G. Fridman, Plasma Medicine 6(3), DOI: 10.1615/PlasmaMed.2017019830, January 2017
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Effect of N 2 /O 2 composition on inactivation efficiency of Escherichia coli by discharge plasma at the gas-solution interface K. Zhigang, P. Thopan, G. Fridman, V. Miller, L. Yu, A. Fridman, Q. Huang, Clinical Plasma Medicine, DOI: 10.1016/j.cpme.2017.05.001, May 2017
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Microsecond Pulsed Dielectric Barrier Discharge Plasma Treated Mist for Sanitation of Fresh Produce, Pietro Ranieri, Gerard McGovern, Henry Tse, Alexander Fulmer, Charles Bailey, Mykola Kovalenko, Gary Nirenberg, Vandana Miller, Alexander Fridman, Alexander Rabinovich, and Gregory Fridman, Plasma Sources, Science, and Technology
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Brar, J., et al. "Non-thermal Plasma Treatment of Flowing Water: A Solution to Reduce Water Usage and Soil Treatment Cost without Compromising Yield." Plasma Medicine 6.3-4 (2017).
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Non-equilibrium Plasma Decontamination of Corn Steep Liquor for Ethanol Production: SO2 removal and Disinfection, Anh Huynh, Thomas Li, Mykola Kovalenko, Ryan Robinson, Alexander Fridman, Alexander Rabinovich, Gregory Fridman, Plasma Medicine journal, Special Issue on Plasma Agriculture, 2017 DOI: 10.1615/PlasmaMed.2016018656
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Oxidation of N-Acetylcysteine (NAC) under Nanosecond-Pulsed Non-Thermal Dielectric Barrier Discharge Plasma, Frank JI, Yingying Li, Arben Kojtari, Gennady Friedman, Ari Brooks, Alexander Fridman , Suresh Joshi, Plasma Medicine journal, Special Issue on Plasma Agriculture, 2017 DOI: 10.1615/PlasmaMed.2016018884


Progress 05/01/16 to 04/30/17

Outputs
Target Audience:The target audiences reached by this project includes fresh produce processors, farmers, chemical sanitizer suppliers, fresh produce washing and handling equipment makers, produce marketing boards, diagnostic companies, plasma equipment manufacturers, regulatory agencies, academic faculty and researchers and undergraduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has supported the research training of 5 gradaute students and 6 postdoctoral scholars. Through this interdisciplinary training, these researchers are engaged in both laboratory science and out reach activities. In addition, the interactions among the team members have generated significant degree of cross-discplinary collaborative research. Through industry outreach activities the trainees have received significant exposure to the "real" needs of the industry and also a perspective on the potential pathways for translation of their research towards novel solutions. This project has also supported the educational training of over 30 graduate students in science communication through a novel course focused on science communication for researhcers. The project has led to development of a SEOP (science education outreach program) section focused on food safety.In this section, interdisciplianry group of undergraduates working closely with the gradaute students selected fromthe project team have developed outreach modules focused on food safety for general public, students in elementary and middle schools. The group during this year presented these modules and activities during the UC Davis picnic day. This event is attended by over 20,000 individuals including kids and families. Similarly, Rutgers team has adapted some of these modules and developed other activities to engage middle school students during their visit to the school program in NJ. The project has supported the First International Workshop on Plasma Agriculture (IWOPA-1) at Drexel Universty on May 15- 20th, 2016 with presentations from this USDA project teams and other scientists from 20+ countries involved in plasma agriculture activities The project has enabled transfer of knowledge between the key industry players and university research teams. This transfer of knowledge has been supported through the semi-annual advisory board updates and the annual advisory board meetings. In addition, these meetings have spurred discussions regarding collaborations among the research team and the industry members. This transfer of knowledge has led to a successful funding of a project by a advisory board industry member to evalaute a novel plasma treatment for their process applications. How have the results been disseminated to communities of interest?The results were disseminated through: 1. Peer reviewed publications 2. Presentations at scientific conferences 3. In-class sessions for training undergraduate and graduate students for science communication beyond academia 4. Collaboration with 4-H program and School -garden to fork programs for incorporating food safety activities in school curiculum 5. Industry advisory board meeting 6. Visit with industrial partners 7. Phone meetings with industry partners to explore collaborations What do you plan to do during the next reporting period to accomplish the goals?Summary of the Proposed Work for Year 3 Aim 1: Rutgers University team will be working on developing the numerical model of bacterial transfer kinetics due to flow of wash water. Specific tasks for year three will include: Numerically model the multiphase fluid flow (wash water as continuous phase, and organic matter as dispersed phase) for the benchtop produce washing process Couple fluid flow with microbial attachment kinetics to predict net accumulation of cell numbers per surface area and cell numbers left in wash water Validate the numerical model with data provided by Dr. Nitin's group from UC Davis Start developing a numerical model for single and multiphase flows in an industrial scale flume washing system. To complement the modeling effort, the experimental studies will be conducted at University of California Davis. These experimental studies at UC Davis will focus on: Detachment and attachment kinetics of microbes from fresh produce under the influence of washing conditions. Under this aim, we will specifically evaluate the role of shear stress, surfactants, soil binding polymers and mechanical agitation to measure the rate of detachment and attachment of microbes to fresh produce. These experiments will provide the data such as kinetic parameters for supporting the modeling efforts proposed above. Evaluate the role of surface properties of food contact surfaces in cross-contamination of fresh produce. Design experiments to experimentally validate the numerical simulation results from the Rutgers team. Key Deliverables: Quantitative information on range of shear, flow conditions and surface on microbial detachment and cross contamination Aim 2: Based on the progress in years 1 and 2, the research goals for Year 3 are: Develop bacterial cell mimicking biosensor that can simultaneously assess lipid damage, thiol oxidation and DNA damage induced by sanitizers. This effort with complement the cell based biosensing approaches developed in year 1 and 2 and is selected based on the feedback from the advisory board. Based on the results of year 2, expand EPR based oxidative stress sensing in gram positive and negative bacteria and characterize differences in stress response of these bacteria Point of use optical biosensor device to determine optimal concentration of sanitizer in wash water. Work with Drexel team to develop an assay to validate oxidative stress in bacteria induced by plasma treatment. This task will also aid in developing dosimetry for the plasma treatments. Develop novel approaches to identify biomarkers of oxidative stress induced by sanitizers using state of the art genomic and metabolomics approaches. Key Deliverables: Novel approaches to rapidly measure biological damage induced by sanitizers in wash water, develop fundamental understanding of the activity of sanitizers including plasma and a device to determine optimal concentration of chlorine and peroxide based sanitizers Aim 3: The overall goals of the Aim 3 in year 3 are: Optimize the assay conditions including thephage- bacterial interactions to reduce the detection time from 7 hours to 4 hours with a detection limit of 10 cfu/ml in simulated wash water. Determine the influence of diversity of wash water organic matter in influencing sensitivity and specificity of the assay. Develop approaches to increase the sample volume of wash water currently used for detection of bacteria and expand the assay to detect bacteria from food contact surfaces. These step will require developing and adapting approaches for surface adsorbed bacterial cells as well as concentration of bacteria from large samples In collaboration with a UC Davis based start-up, SonanuTech, develop a prototype biosensing and test and evaluate its efficacy to detect bacteria in field simulated conditions. This task is specifically aimed at translating the results from year 1 and 2 to a device that may be used in the industry. Key Deliverables: Assay to rapidly and specifically detect bacterial contamination of wash water and food contact surfaces and a prototype device to enable translation of this assay to industrial practice. Aim 4:Based on the findings of Year 1 and 2, research goals for Year 3 are: Continue optimization of plasma systems for produce sterilization: Produce sterilization by direct plasma treatment; Produce sterilization by plasma-treated mist; and Produce sterilization by washing with plasma-treated water. Validate range of antimicrobial properties of these systems. Together with UMD validate olfactory properties of treated produce. Together with UC Davis validate oxidative properties of all three plasma systems. Analyze specific input of all individual plasma parameters to the sterilization mechanism in each specific condition: Effect of long-living plasma-generated species; Effect of short-living plasma-generated species; and Effect of non-chemical plasma-generated species (ultraviolet radiation, pulsed electric field, shockwaves, etc). Key Deliverables: Three systems for produce disinfection: (a) Direct plasma treatment system; Plasma misting system; and o Plasma-treated water wash system. Analysis of effect of short-living and long-living chemically active species, generated in plasma, and analysis of non-chemical effect of plasma treatment on produce disinfection in presence of organic load. Aim 5: The planned research activities in aim 5 include: Translate success from the research program in year 1 and 2 into a practical application to reduce x-contamination of produce from contaminated bins. This study will be conducted at UC Davis and in collaboration with an industrial partner. Modify the composition of common plastic materials used for totes and bins to introduce non-fouling functionality and evaluate the influence of this modified composition on: (a) attachment of Listeria to the plastic surface; (b) formation of biofilms on the surface; and (c)transferof listeria to selected produce including leafy greens and tomatoes < ><!-- --> Photo and mild heat activated sanitation strategies for fresh produce and food contact surfaces. Teaching and Outreach Activities: These activities represent development of educational and teaching programs as well as industry and intl. outreach to develop partnerships for translating the technology innovations In collaboration with the SEOP (Science education outreach program), the Garden to Fork section was started in 2015 with the intention to introduce food science and food safety to middle and high school students. We plan to further build on this program with an overall aim to develop activities for the school curriculum. Science communication graduate seminar course at UC Davis with a focus on food safety and science communications Organize visits and meeting with industry partners to initiate testing of prototypes and evaluate translation of the proposed innovations Develop a graduate course on "food safety engineering" and evaluate possibility of developing an online version of it. Incorporating plasma-assisted food safety applications and scientific background into Prof. Alexander Fridman's "Plasma Engineering" course, offered to graduate and undergraduate students (currently >120 students are enrolled. Incorporate outreach activities and commercialization efforts related to Food Safety applications being investigated in this project. PI at Rutgers University (Dr. Karwe) will offer Byrne freshman seminar in Spring semester (2017) to cover various topics in Food Processing, Food Science, and Food Safety; which will include a module on cross-contamination and produce safety.

Impacts
What was accomplished under these goals? The overall research goal of this project is to reduce/eliminate cross-contamination of fresh produce during a washing process. To achieve this goal, we are developing an integrated approach based on combination of understanding the influence of mechanical aspects of wash systems, developing state of the art biosensing approaches for process validation and novel sanitizer technologies and self generating antimicrobial materials for food contact surfaces during processing. With this overall goal the key accomplishments of this project were: 1. Demonstrated that cross-contamination of fresh produce with bacteria is significantly favored as compared to removal of bacteria from the plant surface. This is predominatly due to combination of surface properties of leafy vegetables, their contact with water and affinity of the bacteria for the plant surface This emphasizes the significance of controlling crosscontamination. 2. Discovered that the presence of surfactants in wash water can enhance removal of bacteria from fresh produce further highlighting the significance of limited contact between wash water and fresh produce. 3. Using numerical modeling and experimental studies, demonstrated that shear stress on produce surface can enhance removal of bacteria from the plant surface. 4. Developed a mathematical frame work to quantify the shear stress on produce surface during washing in the presence of organic load. Understanding the effect of shear stress on bacteria-produce interaction will help improve the desgin of produce washing systems and minimize the probability of cross-contamination during produce washing. 5. Designed two biosensing approaches to rapidly assess the sanitation efficacy of wash water. In the first approach, we demonstrated that the intracellular uptake of exogenous fluorescently labeled glucose could be an effective indicator of sanitation efficacy of wash water. This assay was validated in the presence of lettuce leaf samples. In our ongoing effort, we are evalauting the role of endogenous indicators of oxidative damage in cells and correlating their response with reduction of bacterial count. 6. Developed an innovative EPR based approach to measure oxidative stress in bacteria upon exposure to sanitizers and its correlation with oxidative stress measurements in model liposomes. 7. Demostrated three orders of magnitude enhancement in detection efficacy of bacteria (10 cfu/ml) using a combination of bacteriophages and nanophotonics in a simulated wash water in less than7 hours. 8. Mechanistic understanding of plasma physics and plasma chemistry of non-equilibrium discharge interaction with droplets and sprays in a flow-through system with atmospheric air and water in droplets. Discovery of importance of short-living and temperature-sensitive peroxynitrite radical on anti-pathogen properties of direct plasma and plasma-treated liquids. This discovery leads to improvement in the design of plasma-based food safety systems. 9. Understanding of the effects of plasma treatment on the olfactory properties of fresh produce and development of plasma based prepared food and fresh produce disinfection systems. 10. Demonstrated that "self-regenerating antimicrobial coatings" can significantly inactivate bacteria both in suspension with organic load and also in biofilms 11. Illustrated the rechargabiltiy of the antimicrobial coatings and its efficacy in reducing bacterial load after repeated exposures 12. Discovery of novel food grade compounds that in combination with sub-lethal physical stresses such as light can inactivate bacteria in wash water and can aid in reducing the risk of x-contamination Overall, these accomplishments highlight the success of interdisciplinary research and its impact in developing innovative solutions to address the unmet challenges for the fresh produce industry.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Andrea Cossu, Duygu Ercan, Qingyang Wang, Wendy Ann Peer, Nitin Nitin, Rohan V Tikekar, Antimicrobial effect of synergistic interaction between UV-A light and gallic acid against Escherichia coli O157: H7 in fresh produce wash water and biofilm, Innovative Food Science & Emerging Technologies 37, 44-52
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Enhanced removal of food borne pathogens from fresh produce using surfactants during simulated washing of fresh produce
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Biocidal and Rechargeable N-Halamine Nanofibrous Membranes for Highly Efficient Water Disinfection
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Enhanced Antimicrobial Activity Based on a Synergistic Combination of Sub-Lethal Levels of Stresses Induced by UV-A Light and Organic Acids
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Influence of exposure time, shear stress, and surfactants on detachment of Escherichia coli O157:H7 from fresh lettuce leaf surfaces during washing process
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Mechanically robust N-Halamine Grafted PVA-co-PE membranes with Renewable Antimicrobial Activity
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Cossu A.; Ercan D.; Wang Q.; Nitin N.; Tikekar R. V., Antimicrobial Efficacy and Mechanism of Ultraviolet Light Exposed Gallic Acid Against Escherichia Coli O157:H7 in Fresh-Produce Wash water, IFT-AMFE, Chicago, IL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wang Q.; Tikekar R. V., The Ability of Gallic Acid to Generate Reactive Oxidative Species (Ros) Upon Exposure to UV Light, IFT-AMFE, Chicago, IL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Salvi D. and M.V. Karwe (2016). Understanding microbial attachment and detachment to produce surface during washing. Institute of Food Technologist Annual Meeting and Food Expo, Session no. 013, Chicago, IL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: N. Nitin, Novel Antimicrobials, Process Engineering and Biosensing: An Integrated Approach to Food Safety, Global Food Safety and Antimicrobial Resistance, 2016, China-Hong Kong
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: N. Nitin, Biomaterial Engineering and Sensing Technologies for Improving Food Quality and Safety, Congress International Food Technology, Argentina
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: N. Nitin, An Integrated Approach to Eliminate Cross-Contamination during Washing, Conveying, Handling and Packaging of Fresh Produce, IFT, Chicago
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Mechanisms of Biocidal Activity of Dielectric Barrier Discharge Air Jet with Misting, K Patel, A Mannsberger, A Suarez, H Patel, M Kovalenko, A Fridman, V Miller, G Fridman, Special Issue on Plasma Agriculture, Plasma Medicine journal, 2017
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Non-equilibrium Plasma Decontamination of Corn Steep Liquor for Ethanol Production: SO2 removal and Disinfection, Anh Huynh, Thomas Li, Mykola Kovalenko, Ryan Robinson, Alexander Fridman, Alexander Rabinovich, Gregory Fridman, Plasma Medicine journal, Special Issue on Plasma Agriculture, 2017 DOI: 10.1615/PlasmaMed.2016018656
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Oxidation of N-Acetylcysteine (NAC) under Nanosecond-Pulsed Non-Thermal Dielectric Barrier Discharge Plasma, Frank JI, Yingying Li, Arben Kojtari, Gennady Friedman, Ari Brooks, Alexander Fridman , Suresh Joshi, Plasma Medicine journal, Special Issue on Plasma Agriculture, 2017 DOI: 10.1615/PlasmaMed.2016018884
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Yang Si, Andrea Cossu, Nitin Nitin, Yue Ma, Cunyi Zhao, Bor?sen Chiou, Trung Cao, Dong Wang, Gang Sun, Mechanically Robust and Transparent N?Halamine Grafted PVA-co-PE Films with Renewable Antimicrobial Activity, Macromolecular Bioscience, 10.1002/mabi.201600304
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Andrea Cossu, Phuong Le, Glenn M Young, Nitin Nitin, Assessment of sanitation efficacy against Escherichia coli O157:H7 by rapid measurement of intracellular oxidative stress, membrane damage or glucose active uptake, Food Control 71, 293-300


Progress 05/01/15 to 04/30/17

Outputs
Target Audience:The target audiences reached by this project includes fresh produce processors, farmers, chemical sanitizer suppliers, fresh produce washing and handling equipment makers, produce marketing boards, diagnostic companies, plasma equipment manufacturers, regulatory agencies, academic faculty and researchers and undergraduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has supported the research training of 5 gradaute students and 6 postdoctoral scholars. Through this interdisciplinary training, these researchers are engaged in both laboratory science and out reach activities. In addition, the interactions among the team members have generated significant degree of cross-discplinary collaborative research. Through industry outreach activities the trainees have received significant exposure to the "real" needs of the industry and also a perspective on the potential pathways for translation of their research towards novel solutions. This project has also supported the educational training of over30 graduate students in science communication through a novel course focused on science communication for researhcers. The project has led to development of a SEOP (science education outreach program) section focused on food safety.In this section, interdisciplianry group of undergraduates working closely with the gradaute students selected from the project team have developed outreach modules focused onfood safetyfor general public, students in elementary and middle schools. The group during this year presented these modules and activities during the UC Davis picnic day. This event is attended by over 20,000 individuals including kids and families. Similarly, Rutgers team has adapted some of these modules and developed other activities to engage middle school students during their visit to the school program in NJ. The project has supported the First International Workshop on Plasma Agriculture (IWOPA-1) at Drexel Universty on May 15-20th, 2016 with presentations from this USDA project teams and other scientists from 20+ countries involved in plasma-agriculture activities The project has enabled transfer of knowledge between the key industry players and university research teams. This transfer of knowledge has been supported through the semi-annual advisory board updates and the annual advisory board meetings. In addition, these meetings have spurred discussions regarding collaborations among the research team and the industry members. This transfer of knowledge has led to a successful funding of a project by a advisory board industrymember to evalaute a novel plasma treatment for their process applications. How have the results been disseminated to communities of interest?The results were disseminated through: 1. Peer reviewed publications 2. Presentations at scientific conferences 3. In-class sessions for training undergraduate and graduate students for science communication beyond academia 4. Collaboration with 4-H program and School -garden to fork programs for incorporating food safety activities in school curiculum 5. Industry advisory board meeting 6. Visit with industrial partners 7. Phone meetings with industry partners to explore collaborations What do you plan to do during the next reporting period to accomplish the goals?Aim 1: Rutgers University team will be working on developing the numerical model of bacterial transfer kinetics due to flow of wash water. Specific tasks for year three will include: Numerically model the multiphase fluid flow (wash water as continuous phase, and organic matter as dispersed phase) for the benchtop produce washing process Couple fluid flow with microbial attachment kinetics to predict net accumulation of cell numbers per surface area and cell numbers left in wash water Validate the numerical model with data provided by Dr. Nitin's group from UC Davis Start developing a numerical model for single and multiphase flows in an industrial scale flume washing system. To complement the modeling effort, the experimental studies will be conducted at University of California Davis. These experimental studies at UC Davis will focus on: Detachment and attachment kinetics of microbes from fresh produce under the influence of washing conditions. Under this aim, we will specifically evaluate the role of shear stress, surfactants, soil binding polymers and mechanical agitation to measure the rate of detachment and attachment of microbes to fresh produce. These experiments will provide the data such as kinetic parameters for supporting the modeling efforts proposed above. Evaluate the role of surface properties of food contact surfaces in cross-contamination of fresh produce. Design experiments to experimentally validate the numerical simulation results from the Rutgers team. Key Deliverables: Quantitative information on range of shear, flow conditions and surface on microbial detachment and cross contamination Aim 2: Based on the progress in years 1 and 2, the research goals for Year 3 are: Develop bacterial cell mimicking biosensor that can simultaneously assess lipid damage, thiol oxidation and DNA damage induced by sanitizers. This effort with complement the cell based biosensing approaches developed in year 1 and 2 and is selected based on the feedback from the advisory board. Based on the results of year 2, expand EPR based oxidative stress sensing in gram positive and negative bacteria and characterize differences in stress response of these bacteria Point of use optical biosensor device to determine optimal concentration of sanitizer in wash water. Work with Drexel team to develop an assay to validate oxidative stress in bacteria induced by plasma treatment. This task will also aid in developing dosimetry for the plasma treatments. Develop novel approaches to identify biomarkers of oxidative stress induced by sanitizers using state of the art genomic and metabolomics approaches. Key Deliverables: Novel approaches to rapidly measure biological damage induced by sanitizers in wash water, develop fundamental understanding of the activity of sanitizers including plasma and a device to determine optimal concentration of chlorine and peroxide based sanitizers Aim 3: The overall goals of the Aim 3 in year 3 are: Optimize the assay conditions including thephage- bacterial interactions to reduce the detection time from 7 hours to 4 hours with a detection limit of 10 cfu/ml in simulated wash water. Determine the influence of diversity of wash water organic matter in influencing sensitivity and specificity of the assay. Develop approaches to increase the sample volume of wash water currently used for detection of bacteria and expand the assay to detect bacteria from food contact surfaces. These step will require developing and adapting approaches for surface adsorbed bacterial cells as well as concentration of bacteria from large samples In collaboration with a UC Davis based start-up, SonanuTech, develop a prototype biosensing and test and evaluate its efficacy to detect bacteria in field simulated conditions. This task is specifically aimed at translating the results from year 1 and 2 to a device that may be used in the industry. Key Deliverables: Assay to rapidly and specifically detect bacterial contamination of wash water and food contact surfaces and a prototype device to enable translation of this assay to industrial practice. Aim 4:Based on the findings of Year 1 and 2, research goals for Year 3 are: Continue optimization of plasma systems for produce sterilization: Produce sterilization by direct plasma treatment; Produce sterilization by plasma-treated mist; and Produce sterilization by washing with plasma-treated water. Validate range of antimicrobial properties of these systems. Together with UMD validate olfactory properties of treated produce. Together with UC Davis validate oxidative properties of all three plasma systems. Analyze specific input of all individual plasma parameters to the sterilization mechanism in each specific condition: Effect of long-living plasma-generated species; Effect of short-living plasma-generated species; and Effect of non-chemical plasma-generated species (ultraviolet radiation, pulsed electric field, shockwaves, etc). Key Deliverables: Three systems for produce disinfection: (a) Direct plasma treatment system; Plasma misting system; and Plasma-treated water wash system. Analysis of effect of short-living and long-living chemically active species, generated in plasma, and analysis of non-chemical effect of plasma treatment on produce disinfection in presence of organic load. Aim 5: The planned research activities in aim 5 include: Translate success from the research program in year 1 and 2 into a practical application to reduce x-contamination of produce from contaminated bins. This study will be conducted at UC Davis and in collaboration with an industrial partner. Modify the composition of common plastic materials used for totes and bins to introduce non-fouling functionality and evaluate the influence of this modified composition on: (a) attachment of Listeria to the plastic surface; (b) formation of biofilms on the surface; and (c)transferof listeria to selected produce including leafy greens and tomatoes < ><!-- --> Photo and mild heat activated sanitation strategies for fresh produce and food contact surfaces. Teaching and Outreach Activities: These activities represent development of educational and teaching programs as well as industry and intl. outreach to develop partnerships for translating the technology innovations In collaboration with the SEOP (Science education outreach program), the Garden to Fork section was started in 2015 with the intention to introduce food science and food safety to middle and high school students. We plan to further build on this program with an overall aim to develop activities for the school curriculum. Science communication graduate seminar course at UC Davis with a focus on food safety and science communications Organize visits and meeting with industry partners to initiate testing of prototypes and evaluate translation of the proposed innovations Develop a graduate course on "food safety engineering" and evaluate possibility of developing an online version of it. Incorporating plasma-assisted food safety applications and scientific background into Prof. Alexander Fridman's "Plasma Engineering" course, offered to graduate and undergraduate students (currently >120 students are enrolled. Incorporate outreach activities and commercialization efforts related to Food Safety applications being investigated in this project. PI at Rutgers University (Dr. Karwe) will offer Byrne freshman seminar in Spring semester (2017) to cover various topics in Food Processing, Food Science, and Food Safety; which will include a module on cross-contamination and produce safety.

Impacts
What was accomplished under these goals? The overall researchgoal of this project is to reduce/eliminate cross-contamination of fresh produce during a washing process. To achieve this goal, we aredeveloping an integrated approach based on combination ofunderstanding the influence of mechanical aspects of wash systems, developing state of the art biosensing approaches for process validationand novel sanitizer technologies andself generating antimicrobial materials for food contact surfaces during processing.With this overall goal the key accomplishments of this project were: 1. Demonstrated that cross-contamination of fresh produce with bacteriais significantly favored as compared to removal of bacteria from the plant surface.This is predominatly due to combination of surface properties of leafy vegetables, their contact with water and affinity of the bacteria for theplant surfaceThis emphasizes the significance of controlling cross-contamination. 2. Discovered that the presence of surfactants in wash water can enhance removal of bacteria from fresh produce further highlighting the significance of limited contact between wash water and fresh produce. 3. Using numerical modeling and experimental studies, demonstrated that shear stress on produce surface can enhance removal of bacteria from the plant surface. 4.Developed a mathematical frame work to quantify the shear stress on produce surface during washing in the presence of organic load. Understanding the effect of shear stress on bacteria-produce interaction will help improve the desgin of produce washing systems and minimize the probability of cross-contamination during produce washing. 5. Designed two biosensing approaches to rapidly assess the sanitation efficacy of wash water. In the first approach, we demonstrated that the intracellularuptake of exogeneous fluorescently labeled glucose could be an effective indicator of sanitation efficacy of wash water. This assaywasvalidated in the presence of lettuce leaf samples. Inour ongoing effort, we are evalauting the role of endogeneous indicators of oxidative damage in cells andcorrelating their responsewith reduction of bacterial count 6. Developed an innovative EPR based approach to measure oxidative stress in bacteria upon exposure to sanitizers and its correlation with oxidative stress measurements in model liposomes 7.Demostrated two-three orders of magnitude enhancement in detection efficacy of bacteria (10 cfu/ml)using a combination of bacteriophages and nanophotonics in a simulated wash water in less than 6 hours. 8. Mechanistic understanding of plasma physics and plasma chemistry of non-equilibrium discharge interaction with droplets and sprays in a flow-through system with atmospheric air and water in droplets. Discovery of importance of short-living and temperature-sensitive peroxynitrite radical on anti-pathogen properties of direct plasma and plasma-treated liquids. This discovery leads to improvement in the design of plasma-based food safety systems 9. Understanding of the effects of plasma treatment on the olfactory properties of fresh produce and development of plasma-based prepared food and fresh produce disinfection systems 10. Demonstrated that "self-regenerating antimicrobial coatings" can significantly inactivate bacteria both in suspension with organic load and also in biofilms 11. Illustrated the rechargabiltiy of the antimicrobial coatings and its efficacy in reducing bacterial load after repeated exposures 12. Discovery of novel food grade compounds that in combination with sub-lethal physical stresses such as lightcan inactivate bacteria in wash water and can aid in reducing the risk of x-contamination Overall, these accomplishments highlight the success of interdisciplinary research and its impact in developing innovative solutions to address the unmet challenges for the fresh produce industry.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Cossu A.; Ercan D.; Wang Q.; Nitin N.; Tikekar R. V., Antimicrobial Efficacy and Mechanism of Ultraviolet Light Exposed Gallic Acid Against Escherichia Coli O157:H7 in Fresh-Produce Wash Water, IFT-AMFE, Chicago, IL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wang Q.; Tikekar R. V., The Ability of Gallic Acid to Generate Reactive Oxidative Species (Ros) Upon Exposure to UV Light, IFT-AMFE, Chicago, IL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Salvi D. and M.V. Karwe (2016). Understanding microbial attachment and detachment to produce surface during washing. Institute of Food Technologist Annual Meeting and Food Expo, Session no. 013, Chicago, IL
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: N. Nitin, Novel Antimicrobials, Process Engineering and Biosensing: An Integrated Approach to Food Safety, Global Food Safety and Antimicrobial Resistance, 2016, China-Hong Kong
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: N. Nitin, Biomaterial Engineering and Sensing Technologies for Improving Food Quality and Safety, Congress International Food Technology, Argentina
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: N. Nitin, An Integrated Approach to Eliminate Cross-Contamination during Washing, Conveying, Handling and Packaging of Fresh Produce, IFT, Chicago
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Yang Si, Andrea Cossu, Nitin Nitin, Yue Ma, Cunyi Zhao, Bor?sen Chiou, Trung Cao, Dong Wang, Gang Sun, Mechanically Robust and Transparent N?Halamine Grafted PVA?co?PE Films with Renewable Antimicrobial Activity, Macromolecular Bioscience, 10.1002/mabi.201600304
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Andrea Cossu, Phuong Le, Glenn M Young, Nitin Nitin, Assessment of sanitation efficacy against Escherichia coli O157: H7 by rapid measurement of intracellular oxidative stress, membrane damage or glucose active uptake, Food Control 71, 293-300
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Andrea Cossu, Duygu Ercan, Qingyang Wang, Wendy Ann Peer, Nitin Nitin, Rohan V Tikekar, Antimicrobial effect of synergistic interaction between UV-A light and gallic acid against Escherichia coli O157: H7 in fresh produce wash water and biofilm, Innovative Food Science & Emerging Technologies 37, 44-52
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Enhanced removal of food borne pathogens from fresh produce using surfactants during simulated washing of fresh produce
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Biocidal and Rechargeable N-Halamine Nanofibrous Membranes for Highly Efficient Water Disinfection
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Enhanced Antimicrobial Activity Based on a Synergistic Combination of Sub-Lethal Levels of Stresses Induced by UV-A Light and Organic Acids
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Influence of exposure time, shear stress, and surfactants on detachment of Escherichia coli O157:H7 from fresh lettuce leaf surfaces during washing process
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Mechanically robust N-Halamine Grafted PVA-co-PE membranes with Renewable Antimicrobial Activity


Progress 05/01/15 to 04/30/16

Outputs
Target Audience:The target audiences includes: Fresh Produce Processing Industry, Food Service Industry, Students including graduates, undergraduates, high-middle school students, Working Professionals in Food Process Industry Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?• In collaboration with the SEOP (Science education outreach program), the Garden to Fork section was started in 2015 with the intention to introduce food science and food safety to middle and high school students. We are further building on this program to develop activities for the school curriculum. • Offered the science communication graduate seminar course at UC Davis with a focus on food safety and science communications • Expanded the advisory board membership to include BASF, Campbell Soup, OLAM foods in addition to previous members that include SmartWash (subsidiary of Taylor Farms), Produce Marketing Board, Ecolab, USDA-WRRC, Advanced Plasma Systems, Farm Del Sol • Conducted conference call based project update meetings with the advisory board members and finalized the date for the first annual on-site advisory board meeting on Nov. 6th, 2015. This meeting will be also attended by research team members from UC Davis, Drexel and Rutgers University. • Conducted the first advisory board meeting at UC Davis in Nov. 2015. • Visited various fresh produce processing companies including Taylor Farms, SmartWash and discussed plans to initiate validation trials in an industrial setting • Incorporated "Plasma in Agriculture" module into Prof. Alexander Fridman's "Plasma Engineering" course offered to Drexel's graduate and undergraduate students (this semester's course has 118 students enrolled). How have the results been disseminated to communities of interest?The results were disseminated through: 1. Peer reviewed publications 2. Presentations at scientific conferences 3. In-class sessions for training undergraduate and graduatestudents for science communication beyond academia 4. Collaboration with 4-H program and School -garden to fork programs for incorporating food safety activities in school curiculum 5.Industry advisory board meeting 6. Visit with industrial partners 7. Phone meetings with industry partners to explore collaborations What do you plan to do during the next reporting period to accomplish the goals?Aim 1: Rutgers University team will be working on developing the numerical model of bacterial transfer kinetics due to flow of wash water. Specific tasks for year two will include: (a) Numerical modeling of multiphase flow and prediction of shear forces and velocity profile near the surface of the produce (b) Kinetics of microbial attachment to fresh produce and measure the role of flow conditions, organic content and differences between pathogenic and non-pathogenic microorganisms. To complement the modeling effort, the experimental studies will focus on: (a) Detachment and attachment kinetics of microbes from fresh produce under the influence of washing conditions. Under this aim, we will specifically evaluate the role of shear stress, surfactants, soil binding polymers and mechanical agitation to measure the rate of detachment and attachment of microbes to fresh produce. These experiments will provide the data for supporting the modeling efforts proposed above. (b) Evaluate the role of mechanical agitation and suspended particle attached microbes in cross-contamination of fresh produce. (c) Design experiments to experimentally validate the numerical simulation results from the Rutgers team. Aim 2: Based on the progress in year 1, the research goals for Year 2 are: (a) Optimize the spin probe labeling approach to measure sanitizer efficacy in the presence of organic content (b) Evaluate the sensitivity of the EPR approach for selected sanitizers include chlorine (c) Based on the success in year 1, develop a point of use optical spectroscopy assay to measure efficacy of sanitizers in the presence of organic content and fresh produce (d) Work with Drexel team to develop an assay to validate oxidative stress in bacteria induced by plasma treatment. This task will also aid in developing dosimetry for the plasma treatments (e) Develop novel approaches to identify biomarkers of oxidative stress induced by sanitizers using state of the art metabolomics approaches Aim 3: The overall goals of the Aim 3 in year 2 are: (a) Determine the optimum conditions for phage amplification following infection of a target pathogenic bacterium. This will involve a systematic variation of incubation time, temperature, and concentration of phages as a function of bacterial concentration. It is necessary to identify these secondary phages as distinct from the primary infectious phages. We will attempt to use EdU as a label that is incorporated during phage multiplication within the host. We shall also explore the use of alternative separation methods of secondary and primary phages, possibly using a magnetic nanoparticle extraction. (b) Finite element modeling of phage trapping into the wells of a photonic crystal will inform our design of the experimental protocol for the sensor by allowing us to rapidly optimize flow rates, electrophoretic voltages on our chip and channel design. (c) We plan to work on developing a suitably low priced photonic device for our sensor. A major goal is the surface modification of the chip to offer a hydrophilic surface to support suitable flow rates of sample. The design of the chip will be optimized to enhance a red excitation wavelength that will be supplied by a new diode laser which operates with a narrow line width, single frequency. This will improve our ability to block backscattering of the laser radiation with sharp long pass filters and a sharp dichroic mirror. Our current laser does not operate stably with a single frequency. Aim 4: Based on the findings of Year 1, research goals for Year 2 are: (a) Optimize the electrode for the forward vortex gliding arc plasmatron system for flowing water production with: • Flow rate of 50ml/min and above; • pH reduction to the range of 2-5; • H2O2 generation over 10 mg/l. (b) Validate range of antimicrobial properties of this system. (c) Together with UMD validate olfactory properties of treated produce. (d) Together with UC Davis validate oxidative properties of the plasma-treated water. (e) Analyze shelf-life of the treated water depending on water type, additives, and plasma treatment parameters. Aim 5: The planned research activities in aim 5 include: (a) The halamine precursor films in thickness of 60-100µm will be treated using a diluted chlorine bleach to activate self-decontaminating functions. Both precursor and chlorinated polymers will be evaluated in mechanical properties such as tensile strength, modules, bending flexural, transparency, and bactericidal functions. (b) Biocidal efficacy of the polymers will be evaluated in Nitin's lab by following a quantitative testing standard set by ASTM E2149 or ASTM E2180. Gram-negative E. coli O157: H7 and gram-positive Listeria monocytogenes will be representative microorganisms for the tests. (c) Ability of the polymeric materials to recharge with bleach and the frequency of recharging necessary to maintain antimicrobial efficacy (defined by 2-3 log CFU reduction in the microbial load) will be evaluated by repeated exposure of the material to different levels of microbial load. Based on these measured optimized functional polymer will be selected for translational studies. (d) Complementary to halamine coatings, the research activities in this aim will also explore the potential of developing photo-activated food grade sanitizers using GRAS compounds. Synergistic interactions among various food grade compounds in simulated wash water will be evaluated. This research will further provide guidance for designing non-chlorine based food grade sanitizers and potential coatings that can enhance antimicrobial activity of food contact surfaces. Teaching and Outreach Activities: These activities represent development of educational and teaching programs as well as industry and intl. outreach to develop partnerships for translating the technology innovations (a) In collaboration with the SEOP (Science education outreach program), the Garden to Fork section was started in 2015 with the intention to introduce food science and food safety to middle and high school students. We plan to further build on this program with an overall aim to develop activities for the school curriculum. (b) Science communication graduate seminar course at UC Davis with a focus on food safety and science communications (c) Organize visits and meeting with industry partners to initiate testing of prototypes and evaluate translation of the proposed innovations (d) Develop a graduate course on "food safety engineering" and evaluate possibility of developing an online version of it. (e) Initiate collaboration with the Sacramento community college program to develop visual arts description of food safety challenges and community education opportunities. (f) Organizing the 1st International Workshop on Plasma Agriculture to be held on May15th-20th, 2016 at Drexel (http://www.iwopa.org). This workshop will include presentations from this USDA project participants, among 50 total presenters, including many presentations related to Food Safety. (g) Incorporating plasma-assisted food safety applications and scientific background into Prof. Alexander Fridman's "Plasma Engineering" course, offered to graduate and undergraduate students (i) Incorporate outreach activities and commercialization efforts related to Food Safety applications being investigated in this project. (j) We have established tentative outreach collaboration with colleagues at the Instituto Nacional de Mexico (Merida) who work in food science. They are interested in our sensor technology and food safety and integrity in general. This collaboration will be developed. (k) PI at Rutgers University (Dr. Karwe) is offering Byrne freshman seminar in Spring semester (2016) to cover various topics in Food Processing, Food Science, and Food Safety; which will include a module on cross-contamination and produce safety.

Impacts
What was accomplished under these goals? • Model system to characterize microbial detachment and mathematical modeling of the shear stress on plant leaf surface during washing (manuscript in preparation) • Development of a novel biosensing assay to measure in-situ oxidative stress in bacteria upon exposure to sanitizer (manuscript in preparation). • Three innovative approaches for generation of plasma-treated mist and its antimicrobial testing • New plasma system based on combination of existing 400 Watt forward vortex gliding arc and ultra-fine droplet sprayer with increased water/plasma mixing (two manuscripts in preparation) • Copolymer with n-halamine modification was developed using a graft polymerization reaction in a twin-screw extruder and testing for bacterial control was conducted (manuscript in preparation) • Novel photo activated food grade chemicals were evaluated for photosensitizer activity and this novel sanitation approach demonstrated significant higher microbial reduction in wash water as compared to chlorine (two manuscripts published, and one in preparation) • Multiphoton imaging approach to characterize risk of internalization of bacteria in leafy greens during postharvest processing of produce (one manuscript published) • Established the sub-contracts with Rutgers, Drexel and Univ. of Maryland. • Started organizational activities for the First International Workshop on Plasma Agriculture (IWOPA-1) to take place at Drexel on May 15-20th, 2016 with presentations from this USDA project teams and other scientists from 20+ countries involved in plasma-agriculture activities.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: E Vonasek, N Nitin, The Influence of Cooling on E. coli O157: H7 Infiltration in Fresh Leafy Greens Using a Multiphoton Imaging Approach, Applied and environmental microbiology, 82 (1), 106-115
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: ndrea Cossu, Duygu Ercan, Rohan V Tikekar, Nitin Nitin, Antimicrobial Effect of Photosensitized Rose Bengal on Bacteria and Viruses in Model Wash Water, Food and Bioprocess Technology, 1-11, 2015.
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Duygu Ercan, Andrea Cossu, Nitin Nitin, Rohan V. Tikekar, Synergistic interaction of ultraviolet light and zinc oxide photosensitizer for enhanced microbial inactivation in simulated wash-water, Innovative Food Science and Emerging Tech, 12, 2015.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Antimicrobial effect of synergistic interaction between UV-A light and Gallic Acid against Escherichia coli O157:H7 in fresh-produce wash water