Source: UNIVERSITY OF NEBRASKA submitted to
METHODOLOGICAL EXPLORATION OF RISK-BASED APPROACHES TO IMPROVE MICROBIAL FOOD SAFETY ALONG FOOD PRODUCTION CHAINS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
1011703
Grant No.
(N/A)
Project No.
NEB-31-145
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Dec 20, 2016
Project End Date
Sep 30, 2021
Grant Year
(N/A)
Project Director
Wang, BI.
Recipient Organization
UNIVERSITY OF NEBRASKA
(N/A)
LINCOLN,NE 68583
Performing Department
Food Science & Technology
Non Technical Summary
The reduction of pathogenic and spoilage microbial contamination on food products would have a large impact in reducing the public health risks of having foodborne illnesses, food spoilage risks and the associated economic burden. Managing food related risks involves every step in the supply chain. Therefore, there is a critical need to use a whole food chain approach to manage risks associated with microbial contamination in food products and structured research protocol to minimize selection bias of scientific evidence to support the chain approach. Quantitative microbial risk assessment will be applied to investigate the complex dynamic of pathogen contamination along the food supply chain. It will also allow for a systematic identification of the vulnerable points and evaluation of all potential control measures by relating the effects of their application (individually or in combination) on the risks to consumers. Finally, systematic review and meta-analysis approaches will be used to quantify the estimates suitable for the quantitative microbial risk assessment model development.The overall goal is to improve microbial food safety/quality through systematic evidence synthesis, quantitative risk assessment and cost-effectiveness analysis approaches in a variety of pathogen/spoilage bacteria-food issues. The basic expected outcomes will be baseline quantitative risk assessment modeling, focusing on different real-world food safety and spoilage issues throughout the food supply chain. The assessment will consider production/processing procedures and their association with public health impacts or final product quality. The advanced expected outcomes out of the baseline QMRA models will include a generic systematic framework that will facilitate food safety relevant decision making and it will include the following components: 1) systematic methods to collect and synthesize evidence for QMRA development, 2) tools for developing and validating risk-based risk management metrics, such as performance objectives, and 3) a model for integrating public health risk estimates from risk assessment models and economic analysis to weight between efficacies of intervention strategies and the corresponding monetary costs for their implementation. The potential audience will be the food industry and government risk managers that could use the results of this research to design and validate their food safety management systems. Additionally, other scientific researchers could also use the results to advance current quantitative analytical techniques and fill critical data gaps leading to more effective and efficient risk management decision making.
Animal Health Component
0%
Research Effort Categories
Basic
(N/A)
Applied
70%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7123260117020%
7123450117020%
7123260209040%
7123450209020%
Goals / Objectives
The overall goal is to improve microbial food safety through science-based systems approaches. Specifically, we proposed that three approaches will be used, which are the SR and MA for evidence collection and synthesis, QMRA for intervention efficiency evaluation and food standard determination, and CEA for multi-criteria decision making on risk management strategies adoption For the goal of this proposal Campylobacter in broiler chicken and spore-forming bacteria in milk are selected as target risk scenarios. However, the suggested approaches can be extended to other pathogenic and/or spoilage microbes in other food products. The overall goal will be achieved by fulfilling the following specific objectives and studies with investigators and collaborators indicated in parenthesis.Objective 1. Collect and synthesize scientific evidence as inputs for QMRA by SR and MA. Study 1-1. Conduct SR and MA to identify and evaluate interventions that can be implemented in steps at primary production and processing stages of broiler chicken related products. (Investigators: Bing Wang; Collaborators: Jennifer Clarke and Gary Sullivan)Study 1-2. Map the changes of spore-forming bacteria in prevalence and/or concentration along the pasteurized milk supply chain. (Investigators: Bing Wang, Andreia Bianchini, Jayne Stratton; Collaborators: Jennifer Clarke)Objective 2. Develop QMRA models to inform risk management decision making from a food safety perspective.Study 2-1. Develop QMRA to identify critical control points (CCPs) for Campylobacter spp. throughout broiler chicken supply chain and compare relative efficacies of different intervention strategies that can be implemented at CCPs to determine their potential impact on public health risks. (Investigators: Bing Wang; Collaborators: Jennifer Clarke)Study 2-2. Develop a modeling approach to derive PO for spore-forming bacteria in pasteurized milk. (Investigators: Bing Wang, Andreia Bianchini, Jayne Stratton; Collaborators: Jennifer Clarke)Objective 3. Integrate the economic analysis and food safety protection to inform risk management decision making on the intervention adoption?Study 3-1. Conduct CEA to investigate trade-offs between efficacies of intervention strategies and the corresponding monetary costs for their implementation, and to explore how stakeholders would choose between different strategies according to their own risk preferences. (Investigators: Fabio Mattos; Collaborators: Bing Wang)
Project Methods
Objective 1. Collect and synthesize scientific evidence as inputs for quantitative microbial risk assessment (QMRA) by systematic review (SR) and meta-analysis (MA).To complete this task, two studies are proposed to demonstrate the application of SA and MA in extracting evidence from existing observational studies for QMRA. One proposed study will be in the context of Campylobacter in broiler chicken as an example to show how to collect and synthesize data to quantify the efficacy of microbial risk mitigation strategies. The other will be focusing on spore-forming bacteria along milk systems and will quantify the naturally occurring contamination, based in both prevalence and concentration data. These two proposed SR and MA studies cover the most important two types of data inputs of QMRA, as shown in the example study by Smith and colleagues.Objective 2. Develop QMRA models to inform risk management decision making from a food safety perspective.A QMRA model will be developed to evaluate efficacies of production and processing interventions on mitigating public health risks associated with consuming poultry products contaminated with Campylobacter spp. in the US. Poultry products have been identified as an important vehicle for human Campylobacter infections in the US. QMRA starts with the exposure assessment which describes the change in prevalence and concentration of Campylobacter through the pathway from live birds on farms to chicken salad on tables. The final output of exposure assessment will be the probability distribution of an intake dose of Campylobacter organisms in a chicken salad serving at the time of consumption. The dose distribution generated in the exposure assessment will then be linked to a dose-response model to predict the probability of campylobacteriosis due to the consumption of contaminated poultry products. The relative ratio of the predicted probability of illness in a given intervention scenario to that in the baseline scenario will be calculated. The number of cases prevented by an intervention, referred as "global" efficacy, will be estimated by applying the relative ratio for a specific intervention to the annual incidence of gastroenteritis in the US.Another study will be conducted use a traditional second order Monte Carlo simulation model of spore-forming bacteria concentrations from the raw milk collected on dairy farms throughout the time of consumption to generate the uncertainty distribution about the mean risk of spoilage per serving of liquid pasteurized milk. Because the application of a dose-response model is not relevant for spoilage bacteria, the specifications of the end product (pasteurized milk) that are accepted for trading purpose will be used to set the ultimate goal of "high quality milk", equivalent to the concept of "food safety objective". The output of the model will be the risk of a product to be above the specifications of spore-forming bacteria per serving of liquid milk.Objective 3. Integrate the economic analysis and food safety protection to inform risk management decision makingA cost-effectiveness analysis study (CEA) will be conducted to investigate trade-offs between efficacies of intervention strategies and the corresponding monetary costs for their implementation, and to explore how stakeholders would choose between different strategies according to their own risk preferences.This study is essentially composed of three parts. 1) Monetary costs to implement each intervention strategy will be estimated. Cost items for each strategy will be determined from Study 1-1 and 1-2, such that it will be known how each strategy is implemented and what products are needed for their implementation. Data for the calculations will be collected by contacting individuals who adopt those interventions and those who sell products necessary for their implementation. 2) Cost-effectiveness ratios (CER) will be calculated by dividing the monetary costs to implement each intervention strategy by their respective efficacies [23, 24]. Data on effectiveness will come from Study 1-2 and represent the percentage reduction in the campylobacteriosis cases relative to the baseline. Thus CERs will show the monetary cost of each percentage point reduction in illness. 3) CERs will be calculated for each iteration of the simulation in Study 1-2, such that there will be a probability distribution of CERs for each intervention strategy.

Progress 12/20/16 to 09/30/21

Outputs
Target Audience:The target audience group forthe overall projectwas identified as food industry and government risk managers for application purpose and other research scientists and risk assessors for the method development purpose. In the last five years, tasks under 3 objectives were completed to address the food-related human health risk issues relevant to multiple food-pathogen combinations, i.e., spore-forming bacteria and Listeria monocytogenes in milk products and Campylobacter in broiler chicken products. Specifically, the target audience of the proposed studies was summarized as follows. Collection of quantitative data of spore-forming bacteria on milk production chain can aid milk industry to review their design of processing and collectively address the increasing contamination as products move towards the end of the production across all sectors along the fluid milk production chain. The development of a quantitative microbial risk assessment (QMRA) model with the integration of a systematic review of the efficacy of various Campylobacter interventions and cost-effective analysis provided a systems decision support tool for poultry industry risk managers when adopting novel intervention strategies to maximize the control of Campylobacter contamination in broiler products and minimize the monetary costs associated with the intervention implementation. The development of a QMRA model simulating the possible introduction of Listeria monocytogenes from reclaimed water used for the CIP process in pasteurized milk processing described a methodological pipeline to aid the dairy industry with their decision-making in the safety of wastewater reuse, through the determination of a microbial criterion used to set the maximum allowable contamination in the reclaimed water. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two PhD graduate students were involved in the proposed studies. Both of them had successfully graduated, with some of the proposed studies included in their dissertations. Through the completion of the project, the students were trained for the application of quantitative microbial risk assessment, systematic review, and meta-analysis approaches to address food safety issues. They were also offered opportunities to present results in both poster and oral presentation formats in national/international food protection meetings, and published research findings in peer-reviewed journals. Both students are now continuing their careers in academia as a research associate orassistant professor in and outside the U.S., with a primary focus on applying computational tools in support of food safety decision-making. How have the results been disseminated to communities of interest?Dissemination to scientific communities: Results were published in peer-reviewed journals including Food Control (IF=6.652), International Journal of Food Microbiology (IF=5.911), Comprehensive Reviews in Food Science and Food Safety (IF=15.786), Risk Analysis (IF=4.302), and Water Research (IF=13.400). The research findings were also shared in national and international scientific conferences, such as the annual meetings of the international association of food protection (IAFP), the society of risk analysis (SRA), and food safety summits organized by commodity foundations. Dissemination through national and inter-governmental organizations: The published studies were used in support of the preparation of scientific reports and/or food safety provisions by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization, and the U.S. National Advisory Committee on Microbiological Criteria for Foods. Dissemination through private sectors: Results of the studies were shared with the local poultry industry in support of their design of processing plant, and food safety extension educators through workshops through whom the food safety knowledge can be effectively delivered to consumers. What do you plan to do during the next reporting period to accomplish the goals?This is the end of the project.

Impacts
What was accomplished under these goals? Study 1-1. During the first project period, we collected data on how bacterial contamination changed during the processing of broiler chicken using the systematic review (SR) approach, which aimed to collect, appraise and synthesize all possible evidence in the current literature through meta-analysis (MA). For the broiler chicken study, we observed that scalding, chilling, refrigeration, and freezing steps in the processing stage were the most critical steps in reducing the contamination of Campylobacter, whereas physical methods for decontamination were less effective when compared to chemical methods. The results of this study helped us better understand the fate of Campylobacter during chicken processing after harvesting. The outcomes of these studies were used in quantitative microbial risk assessment model development and simulation in study 2-1. We also expect that other risk assessors and researchers studying these subjects to benefit from the results of our study for risk assessment purposes. This study highlighted the importance of SR & MA results to be used in risk assessment studies contrary to the common practice of using data collected from the literature by convenience or best availability. Study 1-2 Systematic evidence collection methods provided a detailed summary of spore-forming bacteria contamination along milk production chains. Results of this SR-MA process showed that the concentration and prevalence of spore-forming bacteria remain stable even with a slight increase throughout the chain. This study provided useful insight for milk industry professionals and regulatory agencies and researchers to re-evaluate the performance of current production systems and trigger a realization that all sectors along the chain are responsible for collectively controlling spore-forming bacteria contamination and protecting the quality of milk products. Study 2-1 A QMRA model was established to simulate the transmission of Campylobacter from the live bird on a farm to the chicken meal on consumers' table, with impact by the environmental factors along the chicken supply chain. Based on the model, we learned that while consumer compliance with the best hygienic practices during the preparation was among the most influencing factors within a farm-to-fork chain in modifying the consumers' risk of Campylobacter infection, better preventive control and monitoring at CCPs during the processing stage are also needed to collectively lower the risk at the point of consumption. In addition, a total of 23 individualand 16 combined mitigation strategies that can be implemented at the processing stage were evaluated, showing that preventing fecal leakage during defeathering and chemical processing aids (organic acids) were found to be most effective in terms of reducing Campylobacter contamination. Study 2-2 Intense pressure on water resources has led to efforts to reuse reclaimed processing wastewater for cleaning purposes in food processing plants. The milk industry produces considerable amounts of wastewater, which can be used for cleaning equipment after appropriate treatment. However, due to naturally occurring microbiological contamination in raw milk, the wastewater is often contaminated, and therefore the reuse of reclaimed wastewater is perceived as risky. Our results indicated reclaimed wastewater with proper treatment can be used for CIP operations for cleaning food contact surfaces in pasteurized milk processing to meet suggested tolerable limits for all population subgroups, at a similar extent as using potable water in current practice. The results of this study are expected to aid further efforts in water reuse for sustainable processing operations and provide guidance for the development and implementation of HACCP of water use in food processing facilities. The methods explored in this study can provide an incentive to establish QMRA frameworks in risk-based decision-making and criteria set for possible applications of wastewater reuse in other fields of the food and agriculture industries. Study 3-1 The results from the cost-effectiveness analysis (CEA) model are expected to reach out to broiler processors who consider applying intervention measures to reduce the contamination of Campylobacter in their products. The measures of cost-effectiveness were defined in two different formats. One format is believed to communicate better with the food safety professionals in the broiler chicken industry who are more concerned about the microbial quality of their products. The other measure was included to better serve the public health risk managers from the perspective of national wide policy design to meet an appropriate public health protection goal. Overall, the CEA model is expected to be a useful tool to increase the feasibility of risk management practices by integrating financial factors into food safety and public health decision-making. With multiple outcomes measured for the interests of different stakeholders, this study could be a framework for data collection, modeling, and analysis for broiler industries and food safety authorities.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: o Onay B. Dogan, Jayne Stratton, Ana Arciniega, Jennifer Clarke, Mark L. Tamplin, Andreia Bianchini, Bing Wang. Quantitative modeling of the survival of Listeria monocytogenes in soy sauce-based acidified food products. International Journal of Food Microbiology. 2022, 21(1): 227-271. https://doi.org/10.1016/j.ijfoodmicro.2022.109635
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: o Onay B. Dogan, Anand Aditya, Juan Ortuzar, Jennifer Clarke, Bing Wang. A systematic review and meta-analysis of the efficacy of processing stages and interventions for controlling Campylobacter contamination during broiler chicken processing. Comprehensive Reviews in Food Science and Food Safety. 2022; 21(1):227-271. https://doi.org/10.1111/1541-4337.12860
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: o Juan E. Ort�zar, Onay B. Dogan, Gustavo Sotomayor, Constanza Jim�nez, Jennifer Clarke, Rolando A. Flores, George M. Gray, John H. Rupnow, Bing Wang. Quantitative assessment of microbial quality and safety risk: A preliminary case study of strengthening raspberry supply system in Chile. Food Control. 2020; 113: 107166. Epub ahead of print on February 18, 2020. https://doi.org/10.1016/j.foodcont.2020.107166
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: o Onay B. Dogan, Yulie E. Meneses, Rolando A. Flores, Bing Wang. Risk-based assessment and criteria specification of the microbial safety of wastewater reuse in food processing: Managing Listeria monocytogenes contamination in pasteurized fluid milk. Water Research. 2020; 171: 115466. Epub ahead of print on January 03, 2020. https://doi.org/10.1016/j.watres.2020.115466
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: o Yangjunna Zhang, Annette M. OConnor, Chong Wang, James S. Dickson, H. Scott Hurd, Bing Wang. Interventions targeting deep tissue lymph nodes may not effectively reduce the risk of salmonellosis from ground pork consumption: A quantitative microbial risk assessment. Risk Analysis. 2019; 39(10): 2237-2258. Epub ahead of print on April 30, 2019. https://doi.org/10.1111/risa.13317
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: o Onay B. Dogan, Jennifer Clarke, Fabio Mattos, Bing Wang. A quantitative microbial risk assessment model of Campylobacter in broiler chickens: Evaluating processing interventions. Food Control. 2019; 100: 97-110. https://doi.org/10.1016/j.foodcont.2019.01.003
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: o Juan Ortuzar, Bismarck Martinez, Andreia Bianchini, Jayne Stratton, John Rupnow, Bing Wang. Quantifying changes in spore-forming bacteria contamination along the milk production chain from farm to packaged pasteurized milk using systematic review and meta-analysis. Food Control. 2018; 86:319-331. https://doi.org/10.1016/j.foodcont.2017.11.038


Progress 10/01/19 to 09/30/20

Outputs
Target Audience:In this year cycle, the Objective 3 was targeted. A cost-effectiveness analysis (CEA) was conducted to investigate trade-offs between efficacies of intervention strategies and the corresponding monetary costs for their implementation, and to explore how stakeholders would choose between different strategies according to their own risk preferences. The CEA model was developed based on the systematic review and meta-analysis and quantitative microbial risk assessment models (QMRA) obtained in Objectives 1 and 2 of this project. The proposed model will primarily inform broiler processors with decision making on establishing mitigation measures to control Campylobacter during post-harvest operations. Using the model, stakeholders can estimate overall cost of implementation versus corresponding effectiveness in terms of reduction of Campylobacter prevalence and concentration in the final product. An alternative audience of this study would be public health risk managers as cost-effectiveness measures can be estimated in terms of cost of implementation of interventions versus the reduction of expected annual number of campylobacteriosis cases nationwide. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One PhD student was trained to conduct the proposed tasks, collect and analyze data, with oral and writing communication capability improved by presenting findings in scientific conference and publications in peer-reviewed journals. How have the results been disseminated to communities of interest?In this year cycle, results of the proposed project were published in a peer reviewed journal and used to support the State of Food and Agriculture (SOFA) 2020, an annual report of FAO. What do you plan to do during the next reporting period to accomplish the goals?The main focus of next year cycle is to publish our findings in peer reviewed journals. There are two more manuscripts of the proposed project are under preparation, including Onay B. Dogan, Anand Aditya, Juan Ortuzar, Jennifer Clarke, Bing Wang. Effects of processing stages and interventions to control Campylobacter contamination in broiler chickens: Systematic review and meta-analysis. Under preparation. To be submitted to Comprehensive Reviews in Food Science and Food Safety. Onay B. Dogan, Fabio Mattos, Bing Wang. Cost-effectiveness analysis of processing stages and interventions to control Campylobacter contamination in broiler chickens. Under preparation.

Impacts
What was accomplished under these goals? ? Impact The results from the CEA model are expected to reach out for broiler processors who consider applying intervention measures to reduce the contamination of Campylobacter in their products. The proposed CEA model provides different measures of cost effectiveness ratios (CER) based on prevalence and concentration of the contaminant in the product after chilling (CERprevalence and CERconcentration) and annual expected number of campylobacteriosis cases within the population (CERcase). The measures of CERprevalence and CERconcentration were defined to communicate better with the food safety professionals in broiler chicken industry who are more concerned about the microbial quality of their products. On the other hand, with the capability of estimating CER from the public health perspective, we expect that CERcase would be a more appropriate tool of communication with public health risk managers in regulatory agencies. Overall, the CEA model is expected to be a useful tool to increase the feasibility of risk management practices by integrating financial factor into food safety and public health decision making. With multiple outcomes measured for the interests by different stakeholders, this study could be a framework for data collection, modeling and analysis for broiler industries and food safety authorities. Outcomes Major activities completed A probabilistic CEA model was developed to assess the relative costs of implementing interventions investigated for both studies in Objectives 1 and 2. Effectiveness of interventions were evaluated using different risk metrics estimated in the QMRA model such as the reduction in prevalence, concentration of Campylobacter in the product and annual number of cases. As the final output of CEA, cost-effectiveness ratio (CER) was defined as the cost of implementing a new intervention per avoided unit of prevalence, concentration or annual number of cases, respectively. The CEA model was developed and simulated using @Risk (version 7.5, Palisade Corp., New York, USA). Model outputs were validated by comparing the baseline estimates to cost factor share and per bird processing cost estimates in literature sources. In the baseline scenario, minimum interventions were assumed to be implemented as defined in the QMRA phase. Costs associated with baseline scenario were estimated based on information about fixed capital costs (FCI), fixed operation costs (FOC) and variable operating costs (VOC) collected from the literature and online sources. In order to estimate the additional costs attributable to the application of alternative interventions, costs associated with specific alternative intervention scenarios were also computed. Additional costs were calculated by taking the cost difference between the alternative and baseline scenarios. Separate models were developed for small- and large-scale broiler processing facilities to account for the difference in cost estimations. Fixed capital investment is estimated using Lang factor (fL) approach. According to this approach, total FCI can be estimated as multiplication of fL. FOC mainly covers rent and equipment maintenance that do not vary by sales, which was estimated as 11% of annual FIC. VOC are usually the greatest portion of cost input in food production systems and raw materials (live broilers) makes the most of it (more than 65%). To estimate the VOCs accurately, information about plant capacity, total working hours and number of workers were also collected. Energy and water consumption estimates were provided by poultry life cycle assessment and energy balance studies available in the literature. Results and discussion At the baseline, cost of processing one broiler chicken was estimated as $1.50/bird for small-scale and $0.60/bird for large-scale. Breakdown of input factors and single bird processing costs were compared with literature values to check the validity of the CEA model. The validated model was used to estimate the ratio of the additional cost of implementing interventions to the measure of effectiveness. Based on the target audience and target efficacy measures, three different cost effectiveness ratio (CER) measures were defined, i.e, estimation of CERcase (USD/cases-year) aiming public health and regulatory risk managers, if a specific intervention would be promoted nationwide among the whole broiler industry and lead to a nationwide reduction in campylobacteriosis annual cases attributable to broiler chicken consumption. Based on prevalence and concentration of Campylobacter in the final product, CERprevalence (USD/%-plant-year) and CERconcentration (USD/logCFU-plant-year) were defined to target broiler industry risk managers as these quantities aim to estimate the additional cost of intervention to a broiler processing establishment in return to reductions in prevalence and concentration of Campylobacter. For large scale establishments, the most cost-effective method of reducing annual number of cases would be ASC spray and immersion either used as a single intervention along the processing line or coupled with air chilling applications with the corresponding CERcase ranging from 868-883 USD/cases-year. Other chemical processing aids, such as PAA were estimated to be more costly in reducing number of cases as CER­case values. Data sources were limited for the costs of implementation of interventions at small scale operators, therefore, only immersion chilling with chlorine, PAA immersion and ASC immersion were included in the analysis. Cost-effectiveness ratios were estimated as 3,844 USD/cases-year for ASC immersion, 4,468 USD/cases-year for PAA immersion and 7,626 USD/cases-year for immersion chilling with added chlorine. In terms of cost-effectiveness due to changes in microbiological quality of chicken products in large scale establishments, immersion chilling with chlorine, ASC immersion, ASC immersion coupled with air chilling and PAA spray coupled with air chilling had the lowest CERprevalence indicating that these options would be cost effective. For example, processors would need to invest 47,639 USD on average to achieve 1% reduction in prevalence in their products by implementing air chilling with ASC immersion. For small-scale processors, the average CERprevalence values were estimated as 1,400 USD/percent-plant-year for ASC immersion, and the lower estimates are mainly due to lower costs of implementation for small scale systems. The cost of reducing the Campylobacter concentration in chicken products were significantly higher than for prevalence reduction. For ASC immersion, CERconcentration was estimated approximately as 2.2 million USD/logCFU-plant-year and 3.9 million USD/logCFU-plant-year for ASC spray applications in large-scale operations. All the other scenarios resulted in higher estimates and air chilling was cost-ineffective because of potential increases in bacterial counts in final products. For small scale, CERconcentration­ was estimated as 10,716 USD/logCFU-plant-year for ASC immersion, 13,575 USD/logCFU-plant-year for PAA immersion and 18,976 USD/logCFU-plant-year for immersion chilling with chlorine. With all the three outcome measures considered, it can be suggested that targeting concentration and prevalence reductions would seem cost intensive. Though it seems more applicable for small-scale operators, scale limits the annual output capacity that may result in higher costs per processed bird. Higher costs associated with concentration reduction may be discouraging for the industry to apply new interventions in their processing chains. In general, applying chemical processing aids would be a cost-effective approach from a public health and microbial safety protection point of view.

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Onay B. Dogan, Yulie E. Meneses, Rolando A. Flores, Bing Wang. Risk-based assessment and criteria specification of the microbial safety of wastewater reuse in food processing: Managing Listeria monocytogenes contamination in pasteurized fluid milk. Water Research. 2020; 171: 115466. https://doi.org/10.1016/j.watres.2020.115466


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

Outputs
Target Audience:A quantitative microbial risk assessment (QMRA) model was developed simulating the introduction and passage of Listeria monocytogenes along the milk processing chain, through which the microbiological criterion in terms of Listeria monocytogenes in reclaimed water used for CIP process in dairy facility was determined. The information would mainly aid the food industry with their decision making in safe use of reclaimed water during food processing. Using the proposed model, the efficiency of different wastewater treatment can be quantitatively evaluated and compared and the factors that significantly influence the microbial contamination in CIP water and subsequently in food products can be identified. Therefore, output from this study provide a framework of designing hazard analysis and critical control points plans for the safety management of reclaimed water, which may create opportunities for the implementation of water reuse in the food industry, therefore contributing to sustainable food system approaches. Changes/Problems:In this year cycle, the Objective 2 was targeted with a focus on Study 2-2. It was originally proposed to develop a microbiological criterion of sporeformers in milk products based a risk-based approach. Due to the lack of data in the original proposed scenario, the proposed approach and goal were conducted and achieved in a similar scenario with the availability of relevant data. A quantitative microbial risk assessment (QMRA) model was developed simulating the introduction and passage of Listeria monocytogenes along the milk processing chain, through which the microbiological criterion in terms of Listeria monocytogenes in reclaimed water used for CIP process in dairy facility was determined. What opportunities for training and professional development has the project provided?One PhD student was trained to conduct the proposed tasks, collect and analyze data, with oral and writing communication capability improved by presenting findings in scientific conference and publications in peer-reviewed journals. How have the results been disseminated to communities of interest?In this year cycle, results of the proposed project were presented in three scientific conferences and two scientific manuscripts were submitted to peer reviewed journals, with one published and the other one currently under review after a moderate revision. Journal publications Onay B. Dogan, Jennifer Clarke, Fabio Mattos, Bing Wang. A quantitative microbial risk assessment model of Campylobacter in broiler chickens: Evaluating processing interventions. Food Control. 2019; 100: 97-110. https://doi.org/10.1016/j.foodcont.2019.01.003 Onay B. Dogan, Yulie Meneses, Rolando A. Flores, Bing Wang. Risk-based assessment of the safe reuse of whey-recovered water in cleaning operations: A hypothetical contamination scenario with Listeria monocytogenes in dairy processing. Water Research. 2019. Under review. (R1, moderate revision). Conference presentations Onay B. Dogan, Yulie E. Meneses, Rolando A. Flores, Bing Wang. Quantitative microbial risk assessment for microbiological specification setting for Listeria monocytogenes contamination in wastewater reuse in pasteurized fluid milk processing. Poster platform presentation at Society for Risk Analysis 2019 annual meeting. Arlington, VA. December 8-12, 2019 (M4-J3. Application of QMRA in water quality). Onay B. Dogan, Anand Aditya, Juan Ortuzar, Jennifer Clarke, Fabio Mattos, Bing Wang. Systematic review and meta-analysis on the effects of processing stages and interventions to control Campylobacter contamination in broiler chickens. Poster presentation at International Association of Food Protection Annual Meeting 2019. Louisville, KY. July 21-24, 2019 (P3-231). Onay B. Dogan, Yulie E. Meneses, Rolando A. Flores, Bing Wang. Risk-based assessment and criteria specification of the microbial safety of wastewater reuse in food processing: ManagingListeria monocytogenescontamination in pasteurized fluid milk. Poster presentation at DWFI 2018 Water for Food Global Conference. Lincoln, NE. April 29-30, 2019. What do you plan to do during the next reporting period to accomplish the goals?Next year will be focusing the proposed Objective 3.

Impacts
What was accomplished under these goals? Impact Intense pressure on water resources has led to efforts to reuse reclaimed processing wastewater for cleaning purposes in food processing plants. The milk industry produces considerable amounts of wastewater, which can be used for cleaning of equipment after appropriate treatment. However, due to naturally occurring microbiological contamination in raw milk, the wastewater is often contaminated, and therefore the reuse of reclaimed wastewater is perceived as risky. Our results indicated reclaimed wastewater with proper treatment can be used for CIP operations for cleaning food contact surface in pasteurized milk processing to meet suggested tolerable limits for all population subgroups, at a similar extent as using potable water in current practice. The results of this study are expected to aid further efforts in water reuse for sustainable processing operations and provide guidance for the development and implementation of HACCP of water use in food processing facilities. The methods explored in this study can provide an incentive to establish QMRA frameworks in risk-based decision-making and criteria setting for possible applications of wastewater reuse in other fields of the food and agriculture industries. Outcomes Major activities completed L. monocytogenes contamination throughout the fluid milk processing line was modeled using probabilistic inputs for passage of raw milk received at the processing plant and stored in receiving tanks, pasteurization, storage after pasteurization, partitioning, storage at distribution and consumers' homes, and consumption. Contamination in end products were models primarily from raw milk and possibly contaminated reclaimed water used for CIP. The dose of L. monocytogenes per serving at the point of consumption was then used as an input to the dose-response model to predict the annual number of listeriosis cases and associated disease burden, expressed as DALY among the whole population and separate population subgroups in the United States. Three population subgroups were evaluated in this model considering age- and life stage-related differences in sensitivity to the consumption of contaminated products: the general population (younger than 65 years, excluding pregnant women), the elderly (65 years and older) and pregnant women. These three groups were selected as representative of the total population because in the dose-response model developed by Pouillot et al. (2015), which considered 11 population subgroups, the general population, the elderly and the pregnant encompassed approximately 90% of the total population. Various scenarios were tested to quantify the association of L. monocytogenes contamination in CIP water on the safety of packaged milk products and therefore on public health risks among the overall populations and several population subgroups based on age and life stages, through which a tolerable maximum limit was determined for L. monocytogenes contamination in CIP water to meet the accepted public health risks suggested by WHO. Results and discussion In the "reclaimed water" scenario, it was estimated that the annual number of listeriosis cases was estimated as 3.36, 5.67, and 0.15 for the general, elderly and pregnant population subgroups, respectively, while in the "clean water" scenario, the estimates were 3.33, 5.56 and 0.15, respectively. The results of the "clean water" scenario (potable water for CIP) were similar to those of the "reclaimed water" scenario, indicating reclaimed water with sufficient treatment can be used for cleaning food contact surface to achieve a similar level of protection of microbial safety in milk and of public health among milk consumers. The tolerable limit of contamination in CIP water was estimated as -2 log10CFU/mL to ensure the protection of the most vulnerable subgroup, pregnant women, while higher limits were estimated for the elderly and general subgroups. For the overall population, the acceptable risk limit of 10-6 DALY/person-year was exceeded at a level of -0.5 log10CFU/mL. The limit was exceeded at -1 and 0.5 log10CFU/mL contamination levels for the elderly and general subgroups, respectively. However, the acceptable risk limit was exceeded at a lower contamination level, -1.5 log10CFU/mL, among pregnant women, a more vulnerable population group. However, this limit was still considered unacceptable for the more vulnerable pregnant and elderly subgroups, where the acceptable risk limit was exceeded at -1.82 and -1.52 log10CFU/mL, respectively. The higher bound of the 95% confidence interval was observed to exceed the limit at -2 log10CFU/mL for the pregnant women subgroup (Table 6). Therefore, the cutoff for the maximum tolerable contamination can be set as -2 log10CFU/mL. L. monocytogenes in the water used for CIP cleaning purposes to ensure that the risk posed to the most vulnerable population is controlled below the acceptable level of risk. Based on this study, wastewater reclaimed from cheese whey production by reverse osmosis and ultrafiltration treatment can comply with the proposed microbiological criteria and be used for CIP while maintaining a similar level of microbial food safety and public health protection as potable water. The results of the scenario analysis indicate that using reclaimed wastewater for tank cleaning purposes in fluid milk processing plants is possible as long as suitable performance targets are set for the level of contamination in CIP water. Under current natural contamination conditions with typical water treatment options, acceptable risk limits can be achieved for the suggested system; however, in fail situations, the risks could be beyond the acceptable or tolerable limits. Therefore, it is necessary to develop hazard analysis and critical control points (HACCP) plans for the safety management of reclaimed wastewater. QMRA allows the identification and evaluation of potential risks in a defined scenario while also offering key information to develop robust HACCP systems. However, while QMRA is a methodical tool widely applied in different food sectors, it has rarely been introduced in the reuse of reclaimed water. Together with previous work, the results of this study provide valuable information for designing a HACCP plan. Furthermore, the integration of QMRA in the design of prevention and control strategies for the safe management of reclaimed water may create opportunities for the implementation of water reuse in the food industry, thereby contributing to sustainable food system approaches.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: o Onay B. Dogan, Jennifer Clarke, Fabio Mattos, Bing Wang. A quantitative microbial risk assessment model of Campylobacter in broiler chickens: Evaluating processing interventions. Food Control. 2019; 100: 97-110. https://doi.org/10.1016/j.foodcont.2019.01.003
  • Type: Journal Articles Status: Under Review Year Published: 2020 Citation: o Onay B. Dogan, Yulie Meneses, Rolando A. Flores, Bing Wang. Risk-based assessment of the safe reuse of whey-recovered water in cleaning operations: A hypothetical contamination scenario with Listeria monocytogenes in dairy processing. Water Research. 2019. Under review. (R1, moderate revision).


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

Outputs
Target Audience:Target audience group of this study was first identified as food industry and government risk managers for application purpose and other research scientists and risk assessors for the method development purpose. In this period, food industry professionals and risk managers and research scientists were directly targeted. Collection of quantitative data on milk production chain is expected to aid milk industry to review their design of processing and collectively address the increasing contamination as products move towards the end of the production across all sectors along the fluid milk production chain. It is planned to use the results of this systematic evidence collection phase in quantitative modeling in order to set performance targets for milk production. In addition, other researchers aiming to conduct similar risk assessment research can benefit from the generated data. The development of quantitative microbial risk assessment (QMRA) model and evaluation of possible candidate intervention scenarios is expected to provide systems decision support tool for poultry industry risk managers when introducing novel intervention strategies to control Campylobacter contamination in broiler products. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two graduate students were trained to complete the quantitative microbial risk assessment and systematic review and meta-analysis studies. They were also training for preparing project reports and manuscripts for peer-reviewed journals and presented research findings at international scientific conferences. One student was trainined for systematic review and meta-analysisat a workshop "Introduction to systematic reviews and meta-analysis for food and feed related topics" in Ames, IA, October 31-November 1, 2017. How have the results been disseminated to communities of interest?The results have been communicated with the dairy industry through the Midwest Dairy Association, and Costco and other local broiler chicken processing facilities. What do you plan to do during the next reporting period to accomplish the goals? The cost-effectiveness analysis of Campylobacter control measures at processing (Objective 3. Study 3-1) will be completed using the results of Study 1-1 and 2-1 The manuscript for the work of Study 1-1, systematic review and meta-analysis of Campylobacter mitigation strategies at processing, will be submitted to a peer-reviewed journal for publication.

Impacts
What was accomplished under these goals? (IMPACT) Our aim in this study is to map the pathogenic or spoilage bacterial contamination in broiler chicken and milk products to show the effectiveness of science-based systems approaches to improve microbial food safety. During this reporting period, progress was made on Quantitative Microbial Risk Assessment (QMRA) of campylobacteriosis for broiler chickens and Systematic Review and Meta-Analysis (SR-MA) of spore-forming bacteria contamination of milk production chains. It was observed from the QMRA work that while consumer awareness is the most important parameter within farm-to-fork chain, better preventive control and monitoring at CCPs during processing stage are needed to lower the risk at the point of consumption. In addition, a total of 23 individual and 16 combined mitigation strategies that can be implemented at the processing stage were evaluated, showing that preventing fecal leakage during defeathering and chemical processing aids (organic acids) were found to be most effective in terms of reducing Campylobacter contamination. Systematic evidence collection methods provided a detailed summary of spore-forming bacteria contamination along milk production chains. Results of this SR-MA process shows that concentration and prevalence of spore-forming bacteria remains stable even with slight increase throughout the chain. This study is expected to provide useful insight for milk industry professionals and regulatory agencies and researchers to re-evaluate the performance of current production systems and trigger a realization that all sectors along the chain are responsible for collectively control spore-forming bacteria contamination and protect the quality of milk products. (OUTCOMES) Objective 1. Study 1-1. SR-MA for processing stages and interventions has already been completed as reported in the previous reporting period. A manuscript is currently being prepared to publish in a peer-reviewed journal. Data collection for primary production phase has been completed. Analysis of collected data is under progress. Objective 1. Study 1-2. In order to map the changes of spore-forming bacteria along the pasteurized milk supply chain, a systematic review and meta-analysis (SR-MA) approach was followed similar to Study 1-1. Six major scientific databases in the field were identified and several search strategies were designed for each database. A total of 16,193 articles were collected with the defined search strategy. After relevance screening process, 46 articles found to be relevant and containing required concentration and prevalence data were included in meta-analysis. Collected data included prevalence and concentration of spore-forming bacteria on milking machine, raw milk, bulk tank, transport, silo, pasteurized milk and packaged milk. There were 760 data points identified to report concentration and 70 to report prevalence to be included in the meta-analysis. Lack of data was observed especially for prevalence outcome and at milking machine, transportation and packaged milk points. Increasing trends were observed both with prevalence and concentration outcomes throughout the processing stages. In summary, high levels of average contamination was observed from raw milk to final product, indicating an emerging need for control of spore-forming bacteria from raw milk harvesting through product processing phases. This study provided evidence for efforts to create a holistic understanding to milk production systems with increased accuracy. Results of this study are expected to aid industry, regulatory agencies and academic researchers to address effective risk management strategies and to control contamination of milk with spore-forming bacteria. Results of this study will also serve as the basis of Study 2-2, where it is aimed to construct a Monte Carlo simulation model to derive performance objectives for spore-forming bacteria in pasteurized milk. Results of this study indicate that although raw milk is the most important factor affecting the contamination levels and prevalence, there is a potential increase during the complete processing chain. Therefore, it is suggested that control measures should be carefully placed pre-harvest, as well as post-harvest operations along the milk production chain. Based on quality and quantity of the collected evidence, data gaps and low reporting quality were observed on some important stages in production chain and we expect that this SR-MA could serve as a guide for researchers for conducting research and reporting their outcomes. A journal article was published in Food Control, covering this part of the project in detail, as reported in the products section. Objective 2. Study 2-1. A probabilistic QMRA model with modules describing different levels of broiler chicken supply chain was developed. Model was divided into pre-harvest, processing, cold storage, consumption and preparation and hazard characterization modules. Contamination was expressed as prevalence and concentration and their changes through the exposure assessment were described by odds ratios for prevalence and log changes for concentration as model inputs populated from the SR-MA data collected during Study 1-1. To estimate the Campylobacter-related public health impact due to broiler consumption, dose-response model was incorporated in the baseline model, where no intervention strategies were used. Baseline estimates provided a basis to validate the model using foodborne disease and source attribution estimates and served as a comparator to evaluate intervention efficacies. Sensitivity analysis to determine most important input variables (CCPs) and scenario analyses to compare efficacy of alternative processing strategies and interventions were conducted. The model estimated an occurrence of 274 (95% CI: 0 - 561) cases per 100,000 people per year for baseline. This estimate was comparable to recent campylobacteriosis estimates attributable to broiler products. Sensitivity analysis revealed high degree of sensitivity for some of the inputs and showed that consumer practice was the most important factor in terms of food safety and processing stages such as evisceration, scalding and picking were identified as CCPs. In the scenario analysis, 23 single and 16 combination intervention scenarios were evaluated. Most effective interventions were observed as cloacal plugging during defeathering and different chemical processing aids. The results indicate that although the most important part is assigned to consumers, providing safer broiler meat through the supply chain is also critical with careful control and processing interventions. High degree of sensitivity in inputs related to processing also suggest that precise control over CCPs is required since small disturbances in the processing chain may cause an escalation in public health risks. The model is expected to provide a framework for risk managers making risk-based decisions on changes in current poultry processing practices or implementation of alternative intervention strategies. Most of existing QMRA studies available in the literature use data collected from studies found in the literature with a non-systematic search, in contrast to SR-MA approach used in this study. Collecting the data in such a systematic way enabled us to address variability between different studies as much as possible, therefore, providing the most unbiased estimates. For this reason, this study is an example of evidence-based QMRA analyses, which could be a potential example for other researchers aiming to construct similar QMRA model for a variety of food safety applications. This study was orally presented at Society for Risk Analysis 2018 Annual Meeting as reported in the products section. A manuscript is also submitted to Food Control journal and it is currently under editorial review. Study 2-2 and Objective 3. These studies havenot started yet.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Ortuzar, J., Martinez, B., Bianchini, A., Stratton, J., Rupnow, J. and Wang, B. (2018). Quantifying changes in spore-forming bacteria contamination along the milk production chain from farm to packaged pasteurized milk using systematic review and meta-analysis. Food Control, 86, pp.319-331.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Dogan, O. and Wang, B. Oral presentation. A Quantitative Microbial Risk Assessment of Campylobacteriosis through Consumption of Broilers and Evaluation of Processing Interventions. Society for Risk Analysis Annual Meeting 2018. New Orleans, LA. December 2-6, 2018. Available at: http://birenheide.com/sra/2018AM/program/singlesession.php3?sessid=T4-H [Accessed 7 Dec. 2018]. The student presenter (Dogan, O.) received Student Merit Award and travel Award for the work orally presented at the Society for Risk Analysis annual meeting 2018.
  • Type: Journal Articles Status: Under Review Year Published: 2018 Citation: Dogan, D., Clarke, J., Mattos, F. and Wang, B. A quantitative microbial risk assessment model of Campylobacter in broiler chickens: Evaluating processing interventions. Submitted to Food Control in 2018. Under review.


Progress 12/20/16 to 09/30/17

Outputs
Target Audience:Target audience group forthe overall projectwas identified as food industry and government risk managers for application purpose and other research scientists and risk assessors for the method development purpose. This first phase of the study primarily aimed to address the needs of risk assessors and research scientists who can facilitate the efficacy data of different interventions during their research. Poultry processors arealso targeted in this period. Results could be incentive to review and improve their current practices in production facilities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two graduate students were trained to master the systematic review and meta-analysis approached for evidence collection, evaluation and synthsis. How have the results been disseminated to communities of interest?A extension paper was planned to be published in UNL extention website. What do you plan to do during the next reporting period to accomplish the goals?In this reporting period, the first phase of the Objective 1 is completed as post-harvest interventions controlling Campylobacter in broiler chicken. For the second year, pre-harvest interventions will be included, along with Study 1-2: "mapping spore-forming bacteria in pasteurized milk." The rest of the study is planned to proceed as initially suggested.

Impacts
What was accomplished under these goals? Each year, foodborne illnesses were estimated to affect 48 million people in the United States. Most of those cases would be in the form of simple diarrhea or vomiting; however, an unignorable portion of foodborne pathogenic agents could cause serious hospitalizations or even death. The risk of foodborne illnesses can be predictable and avoidable by a well-structured research system for every step in different food production chains. By this way, public health risks can be minimized, together with the cost due to illnesses product spoilage. Our aim in this study is to map the pathogenic and/or spoilage bacterial contamination in broiler chicken and milk products to show the effectiveness of science-based systems approaches to improve microbial food safety. During the first project period, we collected data on how bacterial contamination changed during processing of broiler chicken using the systematic review (SR) approach, which aimed to collect, appraise and synthesize all possible evidence in the current literature through meta-analysis (MA). For the broiler chicken study, we observed that scalding, chilling, refrigeration and freezing steps in the processing stage were the most critical steps in reducing the contamination of Campylobacter, whereas physical methods for decontamination were less effective when compared to chemical methods. The results of this study helped us better understand the fate of Campylobacter during chicken processing after harvesting. We will use the outcomes of these studies into quantitative microbial risk assessment model development and simulation in future objectives of this project. We also expect that other risk assessors and researchers studying on these subjects to benefit from the results of our study for risk assessment purposes. This study highlighted the importance of SR & MA results to be used in risk assessment studies contrary to the common practice of using data collected from the literature by convenience or best availability. Objective 1. Collect and synthesize scientific evidence as inputs for QMRA by SR and MA Study 1-1. Conduct SR and MA to identify and evaluate interventions that can be implemented in steps at primary production and processing stages of broiler chicken related products. SR and MA studies were initiated by asking the research question: "Is there evidence from literature that processing-level interventions can reduce Campylobacter spp. prevalence and/or concentration on the broiler carcasses". To collect the relevant evidence from the literature, six online databases (CAB Abstracts, PubMed, Web of Science, Food Science and Technology Abstracts, Biological Abstracts and BIOSIS Citation Index) were searched. These databases were identified for their relevancy to the subject and were searched using specific search algorithms with the help of a librarian specialized in food science and veterinary medicine. Since the references were collected from multiple sources, duplicate records were removed. Remaining unique references were screened for their relevancy to the research question based on a series of structured inclusion and exclusion criteria by a team of three researchers. Relevant data were then extracted for each identified intervention in the processing chain. Data were collected for 6 different processing steps, namely scalding, defeathering, washing, chilling, storage (refrigeration and freezing) and packaging, together with several interventions implemented along the chain. Data analysis was conducted in R version 3.3.1 (R Core Team,2016) by meta-analysis (MA) and meta-regression (MR) approaches using metafor pack. Results were expressed as either raw mean difference of concentration (log10CFU) or change in prevalence (odds ratio) and are summarized by forest plots which are the visual representation of all the included studies. The results of the SR & MA study suggest that scalding, chilling, refrigeration and freezing are the most effective processing steps in reducing the Campylobacter contamination in broilers in terms of both prevalence and concentration. On the other hand, processes such as chilling or defeathering were found to have little or no effect on reduction of contamination. Some critical parameters in these processes such as temperature, pH, concentration of chemical decontamination agents and exposure time were also evaluated for their impact on the increased efficiency in reducing Campylobacter contamination. There were very few chemical intervention studies conducted within commercial processing plants. Among them, acidified sodium chlorite (ASC) and cetylpyridinium chloride (CPC) were found to be effective in reducing both prevalence and concentration, while trisodium phosphate (TSP) was effective on reducing concentration but little effect on prevalence. Laboratory challenge trials on other chemical decontamination agents were also effective but their efficacy under commercial conditions are still unknown. Physical decontamination methods such as crust freezing, steam, ultrasound, ultraviolet light or super-chilling were also investigated. Most of these methods were reported to be tested using model equipment and not frequently used in poultry industry. Hence, further studies are needed to test the efficacy of these treatments at a full scale. For this reason, information on effect of these treatments on prevalence is very limited but interventions like crust freezing, super-chilling, hot water, steam pasteurization, ultrasound and steam ultrasound were observed to be effective in reducing the concentration of Campylobacter. Findings of systematic review and meta-analysis provides an insight for the whole process and provides an advancement from the current level of knowledge on Campylobacter in broiler chicken processing. Chicken producers can review their systems and be wary about the points where the spread of contamination can occur. Researchers can benefit from plenty of data to fill data gaps encountered during research. For the future of this project, it is aimed to introduce data to a quantitative microbial risk assessment (QMRA) model in a farm-to-fork continuum in order to simulate the effect of treatment methods on public health aspects and contribute to a generic systematic framework for relevant food safety decision making processes. Until recently, QMRA modelling process was based on data collected on a basis of convenience in most of the studies. However, this approach brought about some unwanted and unmeasurable bias to the risk assessment process. SR & MA, in their nature aims to eliminate or identify bias between different data sources. Therefore, there is an increasing trend and encouragement using of data sources collected through SR & MA for better risk assessment practices. For this reason, this study aimed to facilitate QMRA process with SR & MA approaches. We also aimed to report on pitfalls on existing literature such as bias or lack of information on some key variables like variation around the measurements of interest and processing conditions. Therefore, it is expected to provide guidance to primary researchers conducting studies on similar subjects how to better report their findings. Study 1-2. Map the changes of spore-forming bacteria in prevalence and/or concentration along the pasteurized milk supply chain. No accomplishments are achieved yet. Objective 2. Develop QMRA models to inform risk management decision making from a food safety perspective. No accomplishments are achieved on Objective 2 yet. Results of objective 2 are needed to build QMRA models and interpret their outcomes. Objective 3. Integrate the economic analysis and food safety protection to inform risk management decision making on the intervention adoption No accomplishments are achieved on Objective 3 yet. Results of Objective 3 are needed to conduct the cost-effectiveness analysis.

Publications

  • Type: Journal Articles Status: Other Year Published: 2018 Citation: A publication was under preparation "Systematic Review and Meta-Analysis of Efficacy Of Processing Stages and Interventions for Controlling Campylobacter Contamination in Broiler Chicken". The manuscript will be submitted to Comprehensive Reviews in Food Science and Food Safety.