Source: CORNELL UNIVERSITY submitted to
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
Funding Source
Reporting Frequency
Accession No.
Grant No.
Project No.
Proposal No.
Multistate No.
Program Code
Project Start Date
Sep 1, 2019
Project End Date
Aug 31, 2023
Grant Year
Project Director
Wiedmann, M.
Recipient Organization
Performing Department
Food Science
Non Technical Summary
While produce represents a healthy food choice, microbial foodborne disease cases and outbreaks are not infrequently linked to contaminated produce. Transmission of microbes causing foodborne illness through produce is a particular risk is produce is often consumed raw; produce, unlike many other foods, thus is often not exposed to a processing step (such as cooking), which reduces the risk of illness due to microbes. Foodborne illness cases and outbreaks negatively affect the US society in many different ways, including (i) the direct negative impact on public health, (ii) the potential to negatively affect the image of produce, therefore reducing produce consumption (and hence the health benefits associated with produce), (iii) negative economic consequences of produce contamination with disease causing bacteria for farmers and produce associated companies, and (iv) even possible negative consequences for export of US produce and other foods.As foodborne pathogens can enter the produce chain at many parts of the food system (such as irrigation water, in the field, in the processing plant, at retail, and even in consumer homes), this project takes a comprehensive systems approach (from field to consumer) to develop and disseminate new tools to reduce the introduction and transmission of microbes causing foodborne illness through different produce types. This main goal will be pursued through (i) research and development of new digital tools to identify and implement effective control strategies that reduce transmission of microbes that cause foodborne illness; (ii) assembly of a library of computational and digital tools applicable to the produce industry, and (iii) training of industry and students in use of digital food safety tools for the produce industry. This project will not only provide US produce farmers and industry with the tools and long term solutions needed to reduce the transmission of microbes causing foodborne illness, but will also train a large number of individuals to develop and apply digital food safety tools to produce. Long-term, this project will (i) reduce foodborne illness cases transmitted through foods and (ii) help the US produce industry to stay competitive as digital tools are being developed and implemented internationally in agriculture and food production.
Animal Health Component
Research Effort Categories

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
Goals / Objectives
Goal 1: Develop a farm-to-consumer hazard transmission model to facilitate a systems approach to identifying environment appropriate, socially acceptable and cost-effective interventions.Goal 2: Improve GIS-based tools and approaches to reduce produce microbial food safety hazards introduction from agricultural water, environmental and animal sources at the pre-harvest level.Goal 3: Develop and validate simulation models for (i) packing houses, (ii) processing plants and (iii) retailers to facilitate use of in silico tools to optimize pathogen sampling plans and control strategies.Goal 4. Assemble a library of existing models and modelling tools applicable to the produce industry, and review these tools with respect to the intended purpose, utility (pros and cons) and current usage, to facilitate computer enabled food safety decision making.Goal 5: Develop a comprehensive on-line and in-person (mixed model) outreach program to provide technical and systems-based produce food safety training and to enable industry to use modeling tools.Goal 6: Develop graduate and undergraduate teaching modules to train students to use and develop computational and modelling tools for produce safety.
Project Methods
This project will be accomplished by developing technical cores (e.g., "modeling" core; "microbiology" core), which will also have the capability to quickly address emerging issues using inter- and transdisciplinary approaches. Goals 1 - 3 will be accomplished through a combination of statistical, mathematical and spatial modeling approaches as well as field studies in different states, across the different compartments of the produce production and processing system; collaboration with the Cornell Digital Ag Initiative will provide an important resource for these efforts. Field sites and specific crop systems will be targeted to (i) lead to findings that can be generalized to multiple crops and to (ii) focus on high priority crops. For Goal 1, we will develop an overall mechanistic understanding of farm-to-consumer hazard transmission that will include economic cost-benefit assessment capabilities and data-supported weighting of interventions based on (i) cost-effectiveness, (ii) sustainability and (iii) social acceptability; this will allow identification of the optimal approach in a given environment/region. We are aware that FDA completes cost-benefit analysis on proposed food safety regulations; our efforts in refining the scientific relationships in this area will allow for more comprehensive economic estimates. Goals 2 and 3 will focus on developing and validating specific models for (i) pre-harvest, including ag water and fields, and (ii) post-harvest, including packing houses, processing plants, and retail. For these two goals, we will use initial models that we have already developed as starting points and will refine and improve these models as well as develop additional new models as needed; targeted field studies and data collection efforts will be conducted to support model development and validation. As part of goals 1 - 3, we will develop, distribute, and implement standards for conduct of field studies to assure that our study as well as future studies can be integrated through meta-analyses to generalize findings and better inform decisions. For goal 4, we will assemble a library of existing models and modelling tools applicable to produce, including appropriate models developed here (e.g., as part of goals 1 - 3); industry surveys will be conducted to assess current usage, needs, and barriers to use of simulation models and other decision-support tools. These data will be used to design the www page and supporting documentation and will help with the design of industry workshops and training programs. Success of the website will be measured by the number of visits to the website and other relevant statistics. Goal 5 will leverage our existing training expertise to develop on-line and in-person programs that will provide systems-based produce food safety training focusing on (i) use, application, and further development of modeling and risk assessment tools to assess and develop produce food safety practices, and (ii) a series of comprehensive training programs on produce food safety systems for growers, packers, processors, and retailers, focusing on science-based strategies, including those derived from our work. Most of these programs will be supplemental to Produce Safety Alliance (PSA) and FSMA training; as appropriate, we will also integrate topics into PSA and FSMA-related training. Published recommendations will be used to develop effective evaluations of (i) knowledge gain, (ii) behavioral change (e.g., implementation of improved food safety practices), and (iii) economic and social impact of the training. Knowledge gain will be assessed through pre- and post-tests administered at every training. A database of people trained will facilitate follow-up assessments for behavioral change; participants will be surveyed 12 months after the training through a on-line survey with questions to assess (i) change of practices (e.g., use of GIS tools); (ii) costs incurred to implement interventions or changes of practice; (iii) quantifiable improvements as a result of change of practice (e.g., fewer audit issues, fewer indicator or pathogen positive results), and (iv) obstacles to behavioral changes and implementation of new practices. Pre-post test comparisons and survey results will be used to identify and implement improvements to all training programs. Data on implementation costs and the associated improvements will be used to conduct a quantitative ex post evaluation of the economic and social impact of the training workshops. The analysis will employ an instrumental variable (IV) method (e.g., Heckman selection model) to allow for endogeneity in program participation and produce unbiased estimates. Goal 6 will develop 4-week teaching modules for undergraduate and graduate students focusing on the basics of risk assessment and modelling with applications to produce safety from farm to table in order to assure a cohort of future food safety professionals that can apply and further develop the tools developed here as well as similar other tools. Modules will be used and tested at the participating universities and made available for free. All modules will undergo peer-review by industry and academic partners included in this project. Anytime modules are used in a class, we will perform (i) student evaluations after completion of the modules and (ii) summative and formative assessment of student learning.

Progress 09/01/19 to 08/31/20

Target Audience:Goal 1. The key beneficiaries will be fresh produce growers and processors, who will be better able to mitigate E. coli O157:H7 or L. monocytogenes contamination of fresh produce. This project specifically provide data for identification of potential contamination pathways for pathogens entering farm-to-fork food production chain. The project also provide data to help industry to implement sustainable mitigation strategies that are cost-effective, environmentally friendly and socially acceptable in reducing public health risks. Thus, the sustainable and safe produce supply will benefit the consumers as well as the society as a whole. Goal 2. This goal will directly benefit produce growers by reducing the risk of field contamination by pathogens through agriculture water. In addition, this goal will also indirectly benefit processing facilities as fewer pathogens will be introduced into these facilities through the raw material, and consumers, who will benefit from having safer produce. Goal 3. Nothing to report. Goal 4. Nothing to report. Goal 5. The beneficiaries of the extension and outreach programs are stakeholder groups across the produce production, processing, and distribution continuum, including (i) growers, (ii) processors and packing house operators, and (iii) retailers as well as consumer outreach efforts that will also include students that participate in the project. Goal 6. Academic educators, undergraduate and graduate students will directly benefit from the products of this goal as we will develop modules that educators can use to teach undergraduate and graduate students on advanced topics related to produce food safety and statistical modelling. Indirectly, the produce food industry will also benefit as they will be able to hire new personal that are better trained in produce food safety and statistical modelling. Changes/Problems:Goal 1. Nothing to report. Goal 2. We have experienced a delay in the activities planning for this Goal due to the universities' lockdown in response to the COVID-19 pandemic. However, we do not foresee this delay to extend through the next reporting period and no change will be required in our timeline or scope. Goal 3. Nothing to report. Goal 4. Nothing to report. Goal 5. Nothing to report. Goal 6. Nothing to report. What opportunities for training and professional development has the project provided?Goal 1. Two postdocs, Drs. Ece Bulut and Sarah Murphy have been trained in setup of a framework for sustainability assessment, framing of the risk questions and the development of farm-to-fork conceptual models. Additionally, an undergraduate student (Hannah Rosenthal) has been trained in produce food safety research, focusing on the consumer perceptions, beliefs and behaviors. Goal 2. This project goal has provided training opportunities in GIS and R based modeling tools for a post-doctoral researcher, PhD student and MS student who were supported on this grant. The post-doctoral researcher was offered a position at University of Florida, which is evidence of an increased skill set, and food safety training. Goal 3. Nothing to report. Goal 4. Nothing to report Goal 5. This project has already involved two PhD graduate students in the development of the produce safety certificate program course framework. The graduate students are integrally involved in the development of the 4 specialized produce safety tracks framework and content, as well as the advanced course requirements and content. The graduate students will continue to be integrally involved in the development of the course content and materials in the future years of the grant. Goal 6. One Research Associate Sr., Dr. Renato Orsi, and one technician, Zoe Wasserlauf, were trained in developing online surveys and were responsible for creating the first framework of the undergraduate-level produce food safety module. Two graduate students, Samantha Bolten and Alexandra Belias, were trained in developing the undergraduate-level produce food safety module slides and participated in the discussion-like recording of the first lecture in this module. How have the results been disseminated to communities of interest?Overall, results to date have been communicated with the project Advisory Council, which includes 20 members; so far this group has met 3 times. Details on specific communication that occurred for the different goals are provided below. Goal 1. Preliminary results have been shared among the members of the external advisory council (comprised of representatives of the produce industry - growers, processors and distributors, trade and research organizations, and government agencies). Additionally, preliminary results have been shared among researchers and students in the academic circles. Goal 2. Preliminary results have been communicated to the Advisory Council, and project collaborators. Future communications and presentations are planned for 2021, including submission of abstracts for the International Association of Food Protection, and draft manuscript for Virginia and Florida specific models. Goal 3. Nothing to report. Goal 4. Nothing to report. Goal 5. The extension and outreach certificate program plans have been shared with the Advisory Council. Goal 6. The first lecture of the undergraduate-level produce food safety module was shared among the other PIs and PDs as well as among all members of the Advisory Council. What do you plan to do during the next reporting period to accomplish the goals?Goal 1. Over the next reporting period, we will complete farm-to-fork conceptual models for E. coli O157:H7-lettuce and L. monocytogenes-cantaloupe commodity-pathogen pairs. We also plan to start building the quantitative microbial risk assessment (QMRA) models based on the elements of the completed conceptual models for each pathogen-food pair and start evaluating the other indicators of food safety sustainability (social, economic and environmental). Goal 2. Over the next reporting period, we will continue our analyses and draft manuscripts of the Virginia and Florida datasets, and other states/regions. We will also continue to develop models based on different levels of complexity to the produce industry; including, first level: temperature, (air/water), rainfall, other characteristics (e.g., water type); second level: first level plus physiochemical parameters (e.g., dissolved oxygen); third level: first and second level plus microbial test data; four level: first, second and third levels plus land-use data. These models range in the levels of difficulty for the stakeholders, for example, it is fairly easy to obtain weather data from public weather stations (first level), to increasing difficulty to monitor and obtain land-use data from GIS software. However, we hope to provide tutorials in the outreach objective. Goal 3. Four produce processing facilities with distinct layouts and geographic locations will be selected for the development of facility-specific Agent-Based Models (ABM). Facilities already participating on other projects involving the PDs and PIs may be selected. New facilities (i.e., facilities not involved in current parallel projects) will be visited by key member on this project to ensure they are appropriate for this goal. Longitudinal microbial data will be obtained from previous sampling efforts or new longitudinal samplings will be carried out if needed. ABM will start to be developed soon after the facilities are selected and the longitudinal data are obtained. Goal 4. Identification of existing models and modelling tools will be carried out in this next reporting period. We anticipate that a high proportion of the literature being used for Goal 1 will be valuable for Goal 4 as well. We also expect to create and apply a web-based survey to assess produce industry practices regarding the use of modeling tools and barriers to using them. Goal 5. During the next reporting period, the course content for the 4 specialized produce safety tracks will be generated. The basic introductory produce safety courses that all participants will be prioritized to be completed first. The subsequent specialized courses for the 4 tracks will be developed next, and finally the advanced courses. Goal 6. Over the next reporting period, we will finalize the undergraduate-level produce food safety module and develop the other three modules planned for this goal. We expect that both the undergraduate-level and graduate level produce food-safety modules will be finalized by the end of the next period while the statistical modelling modules should be initiated by then.

What was accomplished under these goals? Goal 1. Progress was made on the assessment of sustainability of fresh produce food safety, specifically the assessment of the public health indicator of sustainability. Towards that goal, we are using the Modular Process Risk Model (MPRM) framework to model produce contamination prevalence and levels along the farm-to-table production chain. The models are being developed for two produce-pathogen pairs: (i) Escherichia coli O157:H7-lettuce (cut) and (ii) Listeria monocytogenes-cantaloupe (whole and cut), which were selected based on feedback from members of our external advisory council. A preliminary conceptual model was developed that outlines the risk pathway from farm-to-fork contamination chain for the E. coli O157:H7-lettuce commodity-pathogen pair. The E. coli O157:H7-lettuce model has been designed to estimate the number of E. coli O157:H7 cells per serving of chopped romaine lettuce and includes four consecutive modules: (i) growing, (ii) harvest/field packing, (iii) processing/distribution and (iv) consumer. A preliminary version of the E. coli O157:H7-lettuce conceptual model was presented to the project team and the external advisory council, and then updated according to their feedback. A sub-group was identified within the advisory council to further seek input on model design and parameterization (e.g., manure or treated biological soil amendment practices that are of specific interest to the produce industry and stakeholders). Accordingly, the main processes currently considered in the MPRM include (i) lettuce growth in the field, (ii) holding time, (iii) harvest/field packing, (iv) washing and chopping (post-harvest processing), (v) distribution, (vi) retail storage and display, (vii) transportation from retail to home, (viii) home storage, and (ix) consumer washing and preparation. Major considered sources of E.coli O157:H7 contamination in the lettuce MPRM are (i) irrigation water, (ii) soil and/or manure contamination, (iii) harvesting blades, (iv) hands of the workers and/or harvesting belts, (v) wash water (cross-contamination) and cutting equipment at post-harvest processing, (vi) and consumer washing (cross contamination) and preparation. Preliminary works has also started on the development of the conceptual model for the L. monocytogenes-cantaloupe MPRM. Goal 2. Due to COVID-19 restrictions, no sampling efforts were performed during this reporting period. To accomplish our target goal of using GIS-based modeling tools to reduce produce microbial food safety hazards in water, and environmental sources; we conducted a search of available datasets (both published and un-published) on the concentration of indicator organisms and presence of pathogens in surface water surfaces in the United States, and North America, to characterize and identify spatio-temporal factors (e.g., soil properties, meteorological events, and adjacent land-use), and build models to predict pathogen presence (e.g., Listeria monocytogenes, Salmonella), and generic Escherichia coli levels. Raw data was collected from 50 datasets and represented 22 states, 3 Canadian provinces, and an additional dataset from Mexico yielding 112,710 individual data points. All data was organized in Excel for importation into the statistical database R (to allow ease of storage, analysis and visualization). Additionally, R code was developed to mine adjacent land-use buffered at 122, 366, and 1098 meters from the sampled GPS location using the National Land Cover Database (NLCD). This was exacted for all data with GPS points (approximately 1/3). Historical weather data was also pulled from the nearest weather station using the date the sample data point was collected. For example, in Florida, 4 different datasets were used for mined, two of which are unpublished, and we performed analyses to determine associations between Salmonella presence, and indicator organisms (e.g., generic E. coli, fecal coliforms), and proximity to specific land-use categories (e.g., wetlands, cropland, forest, urban), meteorological variables (e.g., air temperature, rainfall), and physiochemical parameters (e.g., turbidity, conductivity). Similar analyses are underway for Virginia, and other states. Analyses are in progress. Goal 5. The development of a national produce safety certificate program that provides training and certification to individuals associated with all segments of the produce industry has been initiated. The courses that will make up the content for the 4 specialized certificate tracks, and the advanced certificate programs have been identified. The 4 specialized certificate tracks are Produce Growers, Produce Packing Houses & Produce Processors, Retail, and Consumer Educators. The basic produce safety courses that will be taken by all tracks include: Introduction to Food Microbiology, Systems Approach to Produce Safety, and Traceability in Produce Systems. For the Produce Growers specialized certificate, in addition to the basic produce safety courses, they will take courses that include: GAPs, and Control of Produce Contamination in the Field. For the Produce Packing Houses & Produce Processors, the courses identified for this specialized certificate will be: GMPs 21 CFR 117, PCQI or HACCP for Packing Houses, and Hygiene and Environmental monitoring. The courses for the specialized certificate for Retail will include: Food Code, and Additional Strategies for Retailers to Prevent Contamination. The Consumer Educators specialized certificate will include: Consumer Produce Safety for Educators. The advanced certificates for the 4 specialized tracks will require one advanced course after completing the course requirements for the respective specialized tracks. In addition, advanced courses for Modeling of Produce Safety and GIS Tools for Produce Safety will be developed as the respective objectives for modeling and GIS tools have been completed. Originally, the certificate program was going to be mixed model of on-line and in-person, but due to the pandemic, the certificate program will be on-line for the first 1-2 years, and may change to in-person and on-line when the pandemic subsides. As part of the industry training, we have also offered one industry webinar on WGS (live on November 24th; 50 registrants; 25 attendees), which specifically addressed the WGS data for the E. coli outbreaks and recalls that occurred during the fall of 2020. Goal 6. Progress was made on (i) assessing the needs for and (ii) initial development of the modules proposed under Goal 6. Briefly, a draft survey on needs assessment related to undergraduate and graduate-level modules to teach (i) produce food safety and (ii) statistical modelling was created and sent to three academic professors who teach food safety at three different US universities. Based on the feedback received from these three educators, a final survey was developed. The final survey had questions on format of the modules (e.g., number of lectures per module, length of each module) and as well as interest of using the modules. Educators responsible for teaching produce-related food safety lectures at 53 academic institutions across the United States were identified, contacted, and asked to complete the survey. Twenty out of the 57 educators contacted completed the survey after 22 days. We also obtained feedback from the Advisory Council during our second quarterly Advisory Council meeting, chiefly on the content of the modules. The surveys indicated that modules containing three 20-40 minutes lectures each would be ideal and most educators that responded the survey showed high interest in using the modules in their own classes, both as a slide set for in-person instruction as well as a recorded lecture for distance learning. We are currently developing of the undergraduate-level produce food-safety module. The first of the three lectures have been finalized and recorded using a discussion-like format (link).