Source: MICHIGAN STATE UNIV submitted to
ENHANCING LOW-MOISTURE FOOD SAFETY BY IMPROVING DEVELOPMENT AND IMPLEMENTATION OF PASTEURIZATION TECHNOLOGIES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
Reporting Frequency
Annual
Accession No.
1005487
Grant No.
2015-68003-23415
Project No.
MICL08503
Proposal No.
2014-06157
Multistate No.
(N/A)
Program Code
A4131
Project Start Date
May 15, 2015
Project End Date
May 14, 2022
Grant Year
2019
Project Director
Marks, B.
Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824
Performing Department
Biosystems and Ag Engineering
Non Technical Summary
Recent outbreaks/recalls due to Salmonella in low-moisture foods, and pending Preventive Controls rules associated with the Food Safety Modernization Act (FSMA), make processing interventions an imperative to ensure the microbial safety of low-moisture food products. Although various technologies exist, they have achieved very limited market penetration, and none will provide a universally acceptable solution. Also, "legacy" technologies not designed as "kill steps" (e.g., drying or baking) now must be validated for this purpose.The overall goal of this coordinated, integrated project is to enhance development, improvement, and commercial adoption of pasteurization technologies for low-moisture foods. The project research activities will include inoculated challenge studies in three Biosafety Level-2(3) pilot plants for evaluation of technologies and testing of validation protocols. Multiple workshops, webinars, and unique curricula development will specifically target professionals in the area of low-moisture foods. Cross-institutional and cross-disciplinary graduate learning modules will fill a gap related to low-moisture food safety and technologies.Research, outreach, and education activities will be highly integrated, outcomes-focused, stakeholder-engaged (including an Industry Advisory Group), and subject to systematic assessment processes. As a result, technology companies, processors, and regulators will be better equipped to evaluate, implement, and validate low-moisture food pasteurization processes.
Animal Health Component
0%
Research Effort Categories
Basic
10%
Applied
75%
Developmental
15%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5015010202015%
5014010202015%
5015010110010%
5014010110010%
7125010202015%
7124010202015%
7125010110010%
7124010110010%
Goals / Objectives
Overall goal: To enhance the development, improvement, and commercial adoption of pasteurization technologies for low-moisture foods, considering efficacy, product quality, regulatory requirements, energy use, and suitability for the target end-users.Specific task objectives:Develop standardized protocols for evaluation/validation of low-moisture pasteurization technologies (e.g., mapping temperature distributions, quantifying process variability, and selecting/preparing/utilizing a non-pathogenic surrogate).Conduct an extensive battery of inoculated challenge studies with representative products treated by multiple process technologies (e.g., steam, radio-frequency, extrusion, drying, gas), including pilot-scale trials in multiple Biosafety Level-2(3) pilot plants, to quantify process characteristics (e.g., efficacy, variability) and to establish "safe harbors."Develop and evaluate improvements of key existing thermal processes previously designed to achieve quality outcomes, but not necessarily pasteurization outcomes (e.g., dryers, baking ovens, roasters), in order to enable implementation of low-cost food safety solutions, particularly for small and medium-sized processors.Develop, implement, and assess multiple outreach, training, and service resources aimed at technology developers, end-users, and validation professionals, including:A multi-criteria technology comparison tool.Sustainable professional training programs, including annual workshops, webinars, and FSMA standardized curriculum modules.A multi-location "Validation Center" that will provide long-term support (validations and on-site training) for equipment companies and processors of low-moisture foods.Develop, test, disseminate, and assess online, graduate-level learning modules focused on low-moisture food safety, pasteurization technologies, and process validation methodologies.
Project Methods
Efforts:The overall project plan consists of bi-directional integration among the three functions (research, extension/outreach, and education). The experimental activity is heavily anchored on our unique capacity to conduct pilot-scale, inoculated challenge studies with at least six technologies in four pilot plants, three of which are Biosafety Level-2(or 3). These tests (Obj. 2) will serve multiple purposes, including: testing the validation protocols (Obj. 1), testing process improvements (e.g., humidity control) applied to legacy thermal processes (Obj. 3), generating data to use in the multi-technology comparison tool (Obj. 4a), and generating case study data to use in training curricula (Obj. 4b) and graduate learning modules (Obj. 5). This unique capacity also makes the proposed multi-location "Validation Center" (Obj. 4c) a viable concept that will provide valuable service to stakeholders during and beyond the project.Objective 1. Standardized validation protocols will be developed that outline detailed steps to reliably conduct a low-moisture pasteurization validation, incorporating the research results from this and prior studies. One key contribution will be evidence-based recommendation regarding the number of replications required for a target outcome, based on quantitative estimates of variability/uncertainty from the pilot-scale studies. The Industry Advisory Group will play a critical role in evaluating the relevance and completeness of this document at the outline, first draft, and final draft stages.Objective 2. An extensive battery of inoculated challenge studies with representative products treated by multiple process technologies (e.g., steam, radio-frequency, extrusion, drying, gas), will be conducted, including pilot-scale trials in multiple Biosafety Level-2(3) pilot plants, to quantify process characteristics and to establish possible "safe harbors." Recognizing that the potential combinations of Salmonella strains, food products, and technologies are limitless, choices have been made to represent distinct and important groups of strains, products, and technologies, which will then be used to report generalizable conclusions and recommendations.Objective 3. Process conditions in pilot-scale tunnel/belt dryers, a spray dryer, and a roasting/baking process will be manipulated to enhance Salmonella lethality. The relationships between process outcomes (e.g., drying rates; product quality) and lethality outcomes (i.e., log reductions) will be quantified and utilized to design proposed process modifications for these legacy technologies, while minimizing negative impacts on product quality and/or process throughput. The modifications will be tested via the pilot-scale trials previously described.Objective 4. Data from inoculated, pilot-scale trials of each technology, along with estimation of capital and operating costs, and input from our Industry Advisory Group, will be used to develop weighted decision models for technology selection, in which the user can input the relative importance of the various factors (e.g., process uniformity vs. payback period). Additionally, standardized training modules will be developed, annual workshops taught, and webinars developed and delivered.Objective 5. Discrete graduate education modules (n~8) will be created initially around the following low-moisture food processing topics: Thermal/steam pasteurization, RF technology, extrusion, gas treatments, coupling inactivation and process models, etc.. Materials will be developed as Open Educational Resources via Creative Commons licenses to maximize the benefit and distribution of the resources (domestically and internationally). Evaluation:The overall evaluation strategy is based on the assumption that evaluation can go beyond accountability issues and can aid program management and improve project outcome. Our project Logic Model shows that we will assess the extent to which our research, education, and outreach outputs, outcomes and impacts have been achieved. Early stage evaluation efforts will focus on monitoring and formative evaluation. An implementation plan will be developed, and program records and participant observation will be used to assess whether key activities are implemented as intended. Feedback methods will be used to collect information from outside stakeholders, including our Industry Advisory Group, trainees, and students, to solicit guidance on optimal implementation. During years 2 and 3, the emphasis will shift to output/outcome evaluation. More structured and quantitative methods (e.g., questionnaires; bibliometric analyses) will assess the extent to which the outcomes specified in our logic model have been produced. For instance, we will assess whether we have helped/enabled low-moisture food processors to modify legacy technologies to enhance lethality outcomes (with specific examples). Particularly noteworthy outcomes (e.g., introduction of new products or processes) will be documented in more detail by follow-up telephone interviews. In the latter stages of the project, the emphasis will shift to impact evaluation. For example, we will assess whether participants in our training programs implemented methods or processes that enhance the reliability of their pasteurization validations. Quantitative and qualitative methods (e.g., interviews with companies, students, and end users), with appropriate controls, will be used to assess the effectiveness of the research, extension, and education activities, including the rate of commercial adoption of new pasteurization technologies. In all cases, we will build on and customize assessment instruments and protocols we developed for prior NSF IUCRC and USDA NIFSI and NIFA research, education, and outreach evaluations. Assessment strategies will include focus groups, face-to-face and telephone interviews, short feedback questionnaires, and follow up questionnaires.

Progress 05/15/19 to 05/14/20

Outputs
Target Audience:Our key stakeholders for this project are: (1) Suppliers of pasteurization equipment for the low-moisture food industry, (2) Dry ingredient suppliers, (3) Processors utilizing or producing ready-to-eat, low-moisture food products, (4) The U.S. Food and Drug Administration (as the relevant regulator), and (5) USDA-NIFA (as the principal investor in this project). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The entire research team (including undergraduates, and graduate students), across the multiple project sites, has been trained in advanced laboratory techniques necessary for conducting experiments with biosafety level-2 pathogens in low-moisture products, which present specific challenges in ensuring worker safety, particular when working with powdered products. How have the results been disseminated to communities of interest?In addition to peer-reviewed scientific journals, project results were presented at the 2019 Annual Meetings of the International Association for Food Protection (IAFP), the American Society of Agricultural and Biological Engineers (ASABE), and other professional/scientific venues. Additionally, communications with key stakeholder groups has occurred via the project webpage (lowmoisture.egr.msu.edu), and the Low-Moisture Task Force at the Institute for Food Safety and Health (IFSH) annual meeting in Chicago. What do you plan to do during the next reporting period to accomplish the goals?Our Logic Model and Administrative Timeline (in the Management Plan) continue to provide the overall framework for the various activities, outputs, outcomes, and impacts over the course of the entire project. We utilize both of these tools as part of ongoing project management and annual accountability for each section of the project. An overall outline of the year-6 activities is as follows. OBJECTIVE 1: The only remaining task under this objective is a meta-analysis of over 200 commercial validation studies (in collaboration with our Industry Advisory Group partner from the Almond Board of California). This meta-analysis (to be conducted by a Ph.D. student at MSU) will provide a singularly unique assessment of the inherent variability and uncertainty in commercial-scale validation of multiple pasteurization technologies. This information will provide processors, equipment suppliers, and the FDA with a framework for evaluating the sufficiency of new technologies and the design of commercial-scale validation studies. OBJECTIVE 2: The key remaining task under this objective is the completion of pathogen-inoculated, pilot-scale validation trials of gas-based pasteurization treatments/technologies. This was delayed partially due to co-PD Subbiah's move from the UA to UNL. OBJECTIVE 3: The only remaining work is to complete the re-analysis of this prior work from the industry entity, validate the improved modeling approach, and distribute it through their existing extensive national network of processors. This last activity was unexpected, and it has occurred as a direct result of multiple stakeholders asking us, now a well-known team of subject-matter experts on low-moisture pasteurization technologies, about the validity of the existing, web-distributed tool. Our engagement with the service provider may be one of the most critical outcomes of this project, as the tool is already nationally distributed and utilized in industry, so our improvement of that tool could have direct and immediate impact on industry validation of baking systems as pathogen control processes. OBJECTIVE 4: We have three remaining webinars queued up, with plans to offer these through IAFP in 2021. OBJECTIVE 5: The one key remaining task on the project deployment of graduate learning modules, which we plan to do at multiple sites within our project team in 2020-2021, including a systematic assessment of the learning outcomes and efficacy of the delivery system. ASSESSMENT PLAN: Consistent with our proposed strategy, the evaluation effort will focus on output/outcome evaluation during years 5. Our efforts in these areas will use more structured and quantitative methods (e.g., questionnaires and bibliometric analyses) and will assess the extent to which the outcomes specified in our logic model have been produced. Primary data will be collected from significant stakeholder groups, including firms participating on our Industry Advisory Group and participants in the various webinars and workshops

Impacts
What was accomplished under these goals? This project is continuing to advance our understanding of the underlying scientific principles and the steps needed to incorporate that knowledge into more reliable implementation of food safety technologies for low-moisture foods. One impediment to commercial adoption of technologies in this sector continues to be limited understanding of the fundamental principles affecting Salmonella resistance to lethal treatments. Therefore, we continue to expand and disseminate a ground-breaking paradigm for describing water effects on Salmonella thermal resistance in low-moisture foods. A critically important feature of this type of CAP project is that findings from our multi-site, cross-comparison studies carry a much higher degree of reliability when making recommendations to stakeholders. This report cannot detail all of the key accomplishments from the past project year; however, some sample accomplishments across the project objectives are listed below. OBJECTIVE 1: Our team completed two extremely unique and seminal studies documenting the importance of standardized protocols for conducting pathogen lethality studies and the utility of the nonpathogenic surrogate Enterococcus faecium for conducting pasteurization validations. The latter is particularly impactful, as it has provided the industry and the FDA with the first systematic evaluation of the domain of acceptability of this surrogate for validating pasteurization technologies across a wide domain of low-moisture foods. Additionally, our team has participated in the development and promulgation of several general and applications-specific guidelines for validating pasteurization technologies (in close collaboration with our Industry Advisory Group). OBJECTIVE 2: Some of the most significant and extensive accomplishments on this project fall under this objective, in terms of the volume, uniqueness, and industry impact of the results. Our team has conducted inoculated pilot-scale technology/process validation studies across four different sites, including steam-based, radio frequency, extrusion, drying, roasting, baking, and gas treatments (pending completion). For several of these technologies (e.g., extrusion), the net result was (as intended) the development of relatively simple response-surface modeling approaches that help establish "safe harbor" domains for achieving the target pathogen control in those systems. These results directly impact the ability of the processors and equipment suppliers to sufficiently validate their systems to ensure product safety and achieve regulatory compliance. In the most recent year, our team, across multiple sites, has continued to focus on developing a novel modeling approach for incorporating the impact of process humidity and product moisture on the thermal resistance of Salmonella during thermal processes, as an important tool in advancing options for validating pathogen control in processes producing formulated products. OBJECTIVE 3: Our results under this objective are some of the most directly impactful in this project, as the entire low-moisture food industry is now technically subject to the Preventive Controls Rules under FSMA. However, the "how to" of regulatory compliance is still an incompletely solved challenge, and our results are directly supporting the industry in moving toward this compliance. For example, our team has demonstrated (across multiple locations) the critical importance of process humidity in thermally-based processing systems (e.g., baking, roasting, drying), and developed, validated, and published extremely novel approaches for incorporating process humidity into thermal inactivation models for Salmonella (across multiple systems). Additionally, our team (via comparative studies across multiple laboratories) has developed a paradigm-altering understanding of the relationships between product moisture content, composition, structure, temperature-dependent water activity (aw), and the influence of these coupled metrics on the thermal resistance of Salmonella in low-moisture foods. The cluster of studies that we have published in this domain have fundamentally challenged the previously standard approach of using room-temperature water activity as the relevant metric in describing water impacts on thermal inactivation of pathogens in low-moisture foods. More recently, an unexpected impact of this work is that a well-known and prominent industry entity (a service provider) that was not part of our Industry Advisory Group published multiple studies and started web-based, national distribution of a spreadsheet-based tool for validating Salmonella reduction in baking systems. That tool did not include any impact of humidity in the prediction of pathogen lethality, which our team has proven can result in significant fail-dangerous errors in process validations. Consequently, our team has engaged with this entity, which has shared some of their raw data, and we have demonstrated (with our own studies and re-analysis of their data) that their approach (which has already been distributed to and is being used by industry) has this critical disconnect. We are now working collaboratively to re-analyze their prior work, propose future tests, and present an improved tool that will incorporate our novel modeling approaches, and which hopefully will be nationally distributed by the partner entity. OBJECTIVE 4: Our team developed and delivered another of our highly successful workshops for industry practitioners responsible for validating low-moisture food safety. This workshop (Validating Pasteurization Processes for Low-Moisture Foods) was expanded from a prior 1.0-day format to a 1.5-day format, based on feedback from prior participants regarding the need for additional depth. The workshop was offered as a pre-meeting event linked to the 2019 Annual Meeting of the International Association for Food Protection in Louisville, Kentucky. Over 76% of the 24 attendees indicated that they had high or very-high responsibility for process validations in the low-moisture food industry, confirming that we were meeting the target audience. Post-workshop assessment of impacts indicated strong positive effects. For example, the mean attendee responses indicated that they were "very confident" (4.04 on a 5.00 scale) that they could/would apply knowledge gained from the workshop in their job. Additionally, 92% of the respondents indicated that this workshop was "more impactful" or "much more impactful" than other workshops they had attended on similar subject matter. Overall, these results indicate that the training component of this project has continued to contribute some of the most important accomplishments and impacts of our work.

Publications

  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Hildebrandt IM, Marks BP, Anderson NM, Grasso-Kelley EM. 2020. Reproducibility of Salmonella thermal resistance measurements via multi-laboratory isothermal inactivation experiments. Journal of Food Protection. 83:609-614.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Gomez CB, Marks BP. 2020. Monetizing the impact of food safety recalls on the low-moisture food industry. J. Food Prot. 83:829-835.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Garces-Vega F, Ryser ET, Marks BP. 2019. Relationships of water activity and moisture content to the thermal inactivation kinetics of Salmonella in low-moisture foods. Journal of Food Protection. 82:963-970.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Ahmad NH, Oztabak C, Marks BP, Ryser ET. 2019. Effect of talc as a dry-inoculation carrier on thermal resistance of Enterococcus faecium NRRL B-2354 in almond meal. Journal of Food Protection. 82:1110-1115.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Steinbrunner PJ, Limcharoenchat P, Suehr QJ, Ryser ET, Marks BP, Jeong S. 2019. Effect of food structure, water activity, and long-term storage on x-ray irradiation for inactivating Salmonella Enteritidis PT30 in low-moisture foods. Journal of Food Protection. 82:1405-1411.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Suehr QJ, Anderson NA, Keller SE. 2019. Desiccation and thermal resistance of Escherichia coli O121 in wheat flour. Journal of Food Protection. 82:1308-1313.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Lui S, J Xu, L Xie, MJ Zhu, J Tang. 2019. Dry inoculation methods for nonfat milk powder. Journal of dairy science 102 (1), 77-86.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Jin Y, J Tang, SS Sablani. 2019. Food component influence on water activity of low-moisture powders at elevated temperatures in connection with pathogen control. Lwt 112, 108257.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Jin Y, J Tang. 2019. Improved design of aluminum test cell to study the thermal resistance of Salmonella enterica and Enterococcus faecium in low-water activity foods. Food Control 104, 343-348.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Xu J, R Yang, Y Jin, G Barnett, J Tang. 2020. Modeling the temperature-dependent microbial reduction of Enterococcus faecium NRRL B-2354 in radio-frequency pasteurized wheat flour, Food Control 107, 106778.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Lin, Yawen; Subbiah, Jeyamkondan; Chen, Long; Verma, Tushar; Liu, Yanhong. 2020. Validation of radio frequency assisted traditional thermal processing for pasteurization of powdered infant formula milk?. Food Control. Volume: 10, 106897
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Verma, Tushar; Subbiah, Jeyamkondan. 2019. Conical twin-screw extrusion is an effective inactivation process for Salmonella in low-moisture foods at temperatures above 65 degrees C?. LWT-Food Science and Technology. Volume 114, 108369.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Chen, Long; Wei, Xinyao; Irmak, Sibel; Chaves, Byron; Subbiah, Jeyamkondan. 2019. Inactivation of Salmonella enterica and Enterococcus faecium NRRL B-2354 in cumin seeds by radiofrequency heating?. Food Control. Volume 103, 59-69. ?
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wei, XY; Lau, SK; Stratton, J; Irmak, S; Subbiah, J. 2019. Radiofrequency pasteurization process for inactivation of Salmonella spp. and Enterococcus faecium NRRL B-2354 on ground black pepper. Food Microbiology. Volume 82, 388-397.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Gomez G, Marks B. 2019. Monetizing the impact of food safety recalls on the low-moisture food industry. Abstract P1-144. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Hildebrandt I, Riddell L, James M, Hall N, Marks B. 2019. Validation of a cracker baking process using predictive modeling. Abstract P1-208. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ahmad NH, Ryser E, Marks B. 2019. Enterococcus faecium NRRL B-2354 as a Salmonella surrogate in validating thermal treatment of dairy powders with different lactose and milk protein compositions. Abstract P1-07. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Steinbrunner P, Ryser E, Dolan K, Marks B, Jeong S. 2019. Quantifying the inactivation of Enterococcus faecium during spray drying. Abstract P1-204. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Xu J, R Yang, Y Jin, G Barnett, J Tang. 2019. Identification of the Lowest Lethality Zone in Wheat Flour Treated with Radio-Frequency Heating and Natural Cooling. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Jin Y, J Tang. 2019. Food Component Influence on the Water Activity and Net Isosteric Heat of Sorption for Low-moisture Foods at Elevated Temperatures. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rane B, A Lacombe, S Sablani, DF Bridges, J Tang, J Guan, VCH Wu. 2019. Identifying Nonpathogenic Salmonella Surrogates for Industrial Scale Treatment of Almonds Using Gaseous Chlorine Dioxide. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Yang R, J. Tang. 2019. Key Factors Influencing Thermal Resistance of Bacterial Pathogens in Low-moisture Foods .Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Perez Reyes ME, Xu J, Zhu M, Tang J, Barbosa-Canovas G. Abstract P1-16. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Lau SK, Wei, X, Subbiah J. 2019. Performance of an Improved Thermal Death Time Sandwich System for Determining the Thermal Death Kinetics of Salmonella. Abstract P1-09. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Verma T, Subbiah J. 2019. Use of Water Activity vs Moisture Content in Response Surface Models for Predicting Microbial Lethality during Extrusion of Low-moisture Foods. Abstract P1-15. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Chen L, Wei X, Lau SK, Subbiah J. 2019. Inactivation of Salmonella enterica and Enterococcus faecium in Cumin Seeds Using Gaseous Ethylene Oxide. Abstract P1-18. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Wei X, Chen L, Lau SK, Thippareddi H, Subbiah J. 2019. Ethylene Oxide Fumigation for Inactivation of Salmonella and Enterococcus faecium nrrl B-2354 in Black Pepper. Abstract P1-22. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Chen F, Aggarwal A, Keller S, Anderson N, Grasso-Kelley E. 2019. Evaluation of methods for inoculating Salmonella into dairy powders. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Hildebrandt I. 2019. Design of a process validation based on statistical power and reliability. Symposium S29. Presented at the Annual Meeting of the International Association for Food Protection. Louisville, KY. July 21-24, 2019.
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Perez Reyes, ME. 2019. Thermal inactivation of Salmonella Enteritidis PT30 and Enterococcus faecium in egg powders at different water activities. Ph.D. dissertation. Department of Biological Systems Engineering. Washington State University. Pullman, WA.


Progress 05/15/18 to 05/14/19

Outputs
Target Audience:Our key stakeholders for this project are: (1) Suppliers of pasteurization equipment for the low-moisture food industry, (2) Dry ingredient suppliers, (3) Processors utilizing or producing ready-to-eat, low-moisture food products, (4) The U.S. Food and Drug Administration (as the relevant regulator), and (5) USDA-NIFA (as the principal investor in this project). Changes/Problems:There are no changes the project scope, goals, or overall action plan. What opportunities for training and professional development has the project provided?The entire research team (including undergraduates, and graduate students), across the multiple project sites, has been trained in advanced laboratory techniques necessary for conducting experiments with biosafety level-2 pathogens in low-moisture products, which present specific challenges in ensuring worker safety, particular when working with powdered products. In order to assess the project's ongoing impact on graduate students participating in the project, our assessment team conducted a survey of all current and former students working on the project (student response rate = 16/16, 100%, alumni response rate = 10/16, 63%). The survey focused on participant characteristics, training evaluation, outcome evaluation, and improvement-oriented feedback. Respondents were primarily current and former PhD students in food science (33%) and biological engineering (42%). Overall, the feedback was very positive. Overwhelming majorities of students and alumni reported participating in a wide range of training opportunities proposed for the project and were very satisfied with most of their experiences (mean = 4.4-4.7/5.0 scale). Respondents were particularly satisfied with opportunities to participate in the development and testing of standardized inoculation methods; surrogate usage; thermal inactivation studies; and opportunities to participate in challenge studies. However, they reported lower availability and satisfaction for experiences related to food quality and some specific food processing technologies. There were virtually no differences between universities in terms of training opportunities and satisfaction with training. In terms of training impacts, students and alumni reported very positive impacts on their professional development, technical knowledge and skills, and professional communication/publication (mean = 4.3-4.5/5.0 scale). They reported a particularly positive impact on opportunities to publish in journals and conferences, their understanding of the factors influencing the selection of appropriate validations methods, and their understanding of the relationships between process outcomes (e.g., drying rates; product quality) and lethality outcomes. Respondents felt their training prepared them for a career in food safety, and increased their interest in and awareness of career opportunities in academia. As two respondents put it, "working alongside many professionals within CAP project has been overwhelmingly positive", "I am very confident that I will have the training for any future job I want". Multiple metrics indicated a desire for more industrial interaction and exposure, which has implications for student career goals and outcomes. We plan to conduct further evaluations focused on career outcomes and professional accomplishments with project alumni closer to the end of the project term. How have the results been disseminated to communities of interest?In addition to peer-reviewed scientific journals, project results were presented at the 2018 Annual Meetings of the International Association for Food Protection (IAFP), Institute of Food Technologists (IFT), the American Society of Agricultural and Biological Engineers (ASABE), and other professional/scientific venues. Additionally, communications with key stakeholder groups has occurred via the project webpage (lowmoisture.egr.msu.edu), the Low-Moisture Task Force at the Institute for Food Safety and Health (IFSH) annual meeting in Chicago (including solicitation of stakeholder input on key priorities for technology purchase decisions), and via the previously mentioned webinars. What do you plan to do during the next reporting period to accomplish the goals?Our Logic Model and Administrative Timeline (in the Management Plan) continue to provide the overall framework for the various activities, outputs, outcomes, and impacts over the course of the entire project. We utilize both of these tools as part of ongoing project management and annual accountability for each section of the project. An overall outline of the year-5 activities is as follows [with the lead co-PDs listed in brackets for each task]: OBJECTIVE 1: a. Conduct meta-analysis of all prior almond industry validation reports [Marks, Anderson, et al.]. b. Develop specific validation guidelines for 1-3 technologies [Marks, Anderson, et al.]. OBJECTIVE 2: a. Complete pilot-scale challenge studies for multiple gas-based treatments [Subbiah, Zhu, et al., including collaboration with other peer CAP projects]. b. Collect (from IAG et al.) critical quality factors to be used in future screening of process acceptability for the various test products [Thippareddi, et al.]. OBJECTIVE 3: a. Complete additional pilot-scale challenge studies for baking processes, with new emphasis on multi-ingredient, formulated products [Grasso-Kelley, Anderson, Marks]. b. Conduct pilot-scale challenge studies for drying processes, including heat/mass/microbial modeling [Jeong, Marks, Grasso-Kelley, et al.]. c. Test pre-treatment modifications to dry heating processes at the pilot-scale [Jeong, Marks, Grasso-Kelley] OBJECTIVE 4a: a. Complete draft decision framework for technology purchase/adoption decision [Marks, Tang, Gray, Subbiah, Anderson]. OBJECTIVE 4b: a. Develop and deliver three new webinars focusing on various aspects of low-moisture pasteurization [Thippareddi, Marks, Anderson, Gray]. b. Deliver a 1.5-day workshop on low-moisture food products at 2019 International Association for Food Protection Annual Meeting [Thippareddi, Anderson, Grasso-Kelley, Marks] OBJECTIVE 4c: a. Develop framework for the Multi-Location Validation Center and pilot-scale processing capabilities at MSU, WSU, UNL, and IFSH [Jeong, Tang, Subbiah, Grasso, Marks]. OBJECTIVE 5: a. Develop 2-3 content modules for beta-testing in graduate courses [Tang, Marks, Subbiah]. ASSESSMENT PLAN: Consistent with our proposed strategy, the evaluation effort will focus on output/outcome evaluation during years 5. Our efforts in these areas will use more structured and quantitative methods (e.g., questionnaires and bibliometric analyses) and will assess the extent to which the outcomes specified in our logic model have been produced. Primary data will be collected from significant stakeholder groups, including firms participating on our Industry Advisory Group and participants in the various webinars and workshops [Gray, Thippareddi, Marks]

Impacts
What was accomplished under these goals? This project is simultaneously advancing our understanding of the underlying scientific principles and the steps needed to incorporate that knowledge into more reliable implementation of food safety technologies for low-moisture foods. One impediment to commercial adoption of technologies in this sector continues to be limited understanding of the fundamental principles affecting Salmonella resistance to lethal treatments. Therefore, we continue to expand and communicate a ground-breaking paradigm for describing water effects on Salmonella thermal resistance in low-moisture foods (detailed below). Additionally, we continue to conduct pilot-scale testing of multiple technologies, including legacy technologies designed for quality outcomes but which now must be validated for food safety outcomes (detailed below). A critically important feature of this type of CAP project is that findings from these multi-site, cross-comparison studies carry a much higher degree of reliability when making recommendations stakeholders. In the past year, significant effort also went into translating research results into improved statistical methods for designing commercial validation studies, novel economic measures of improved pathogen control for low-moisture foods, and additional outreach/training activities (all detailed below). Our team also meets twice per year with our Industry Advisory Group (IAG) - once for an extended scientific exchange and once for an informal professional networking event. The IAG again identified a list of priority topics for our Rapid Response Mini-Projects. The selected project focuses on thermal decontamination of processing equipment with low-moisture food residues. This report cannot detail all of the key accomplishments from the current project year; the reader is encouraged to see the extensive list of project products for greater details. Some sample accomplishments across the project objectives are listed below. OBJECTIVE 1: This project has generated multiple outputs on high-temperature water activity (aw) and the relationship to Salmonella thermal resistance. In one example, moisture-equilibrated powders were inoculated with Salmonella and conditioned to multiple aw at 20°C. Salmonella D80°C-values decreased exponentially with increasing aw, regardless of food matrix and testing method. In another study, Salmonella-inoculated almonds were equilibrated to two moisture (%MC) levels but the same aw, and two aw levels but the same %MC, to test the separate effects of MC and aw. D80°C-values effects were not attributable to aw or %MC. Overall, our results demonstrate that it is critical to understand product moisture status when validating pasteurization technologies. Previously, this project included significant testing of a non-pathogenic surrogate (Enterococcus faecium) for validation of pasteurization technologies. However, there has been a significant gap in actual practice, relative to the application of statistical approaches. Therefore, we applied a reliability analysis to this challenge. Estimations of Salmonella log-reductions from 4 log-reductions of the surrogate were performed, based on Monte-Carlo simulations. When an average 4 log-reductions of the surrogate is observed, 4 log-reductions of the pathogen are expected 37% and 83% of the time in walnuts and almonds, respectively. The level of inactivation necessary to achieve a reliability of 90% was 7.8 and 3.9 log-reductions of the surrogate. Reliability analysis is a critical, but rare, step that should be included in interpretation of commercial-scale validations. OBJECTIVE 2 and OBJECTIVE 3: Our pilot-scale challenge studies are now increasingly focused on formulated food products. As an example, we have completed several projects, at multiple sites, testing the effect of product and process conditions on baking as a pathogen control technology. In one study, model cookies were baked in an oven with controlled temperature and humidity. Bacterial reduction was greater (P<0.05) at higher humidity, even though the product integrated temperature history was lower. Additionally, results suggested that measuring the cold spot alone may not sufficiently characterize microbial inactivation during baking, which is an extremely important finding in design of commercial process validations. In a related study on baking of thin crackers, isothermal inactivation parameters were developed using the raw dough, and then applied to time-temperature curves from actual baking trials. The results clearly demonstrated that this validation method grossly overpredicted (P<0.001) actual lethality. Again, these results are significant, given that there are existing practices and recommendation in the industry that suggest this approach, which we have demonstrated can be fail-dangerous. OBJECTIVE 4: Our team developed and offered three webinars on low-moisture pasteurization in 2018, hosted by the International Association for Food Protection (IAFP) - details listed in the "Other Products" section. Our first webinar yielded the largest ever attendance for an IAFP-hosted webinar, and the three webinars attracted a total of 1,389 registrants and 762 live attendees. Assessment results are reported below. Members of our project team also taught portions of several other workshops, in which we provided content expertise on validation of low-moisture pasteurization technologies (details under "Other Products"). Additionally, we have monetized the impact of food safety recalls on the low-moisture food industry. Financial impacts of recalls were analyzed by computing the Cumulative Abnormal Return (CAR) in stock values over a recall event period. The mean CAR for a 20-day post-recall period was -4.6%. This translated to a mean company loss of $495,000,000 for the recall events analyzed in this study. If implementation of a food safety technology could, as an illustration, reduce recall risk by less than one log, that would translate into a mean annual economic benefit of $2,670,000 in reduced risk for companies like those in the study. Such analyses have potential to positively impact business decisions to invest in food safety technologies. ASSESSMENT: Our independent evaluation team engaged in three significant assessments during the past year: (1) A unique one-year-post-workshop assessment, (2) Assessments of our ongoing webinar series, and (3) An assessment of student experiences working on this CAP project. In addition to a prior immediate-post-workshop assessment of our 2017 IAFP full-day workshop on low-moisture pasteurization validation, we conducted a unique one-year-post-workshop assessment. The results (response rate 51%) documented that the impact of the workshop was measurable and sustained. For example, 87% of the respondents indicated that our workshop was more or much more impactful that others they have attended. Additionally, on a scale of 1-3 (1 = not at all; 3 = a great deal), the mean responses were >2.5 on multiple measures of ongoing application of knowledge gained. For the webinars, attendees were surveyed on knowledge, relevance to professional needs, and suggestions for improvements (response rate 31.7%). Participants reported that the topics were very relevant to their professional interests (Mean = 4.4-4.5/5.0), they gained new knowledge applicable to their work, and were confident they could practice key instructional objectives. Overall, participants reported that they were "very satisfied" with the webinar. Respondents commented that they anticipated using the knowledge gained in their future validation and challenge studies, and in communications with their colleagues. The results of the survey of all current and former students participating in the project are described in the next section on opportunities for training and professional development.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Keller SE, Anderson NM, Wang C, Burbick SJ, Hildebrandt IM, Gonsalves LJ, Suehr QJ, Santillana Farakos SM. 2018. Survival of Salmonella during production of partially sprouted pumpkin, sunflower, and chia seeds dried for direct consumption. J. Food Prot. 81(4):520-527.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Xu, J., Tang, J., Jin, Y., Song, J., Yang, R., Sablani, S.S., Zhu, M.J. 2019. High temperature water activity as a key factor influencing survival of Salmonella Enteritidis PT30 in thermal processing. Food Control 98:520-528.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Liu, S., Rojas, R.V., Gray, P., Zhu, M.J., Tang, J., 2018. Enterococcus faecium as a Salmonella surrogate in the thermal processing of wheat flour: influence of water activity at high temperatures. Food Microbiology 74:92-99.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Liu, S., Xu, J., Xie, L., Zhu, M.J., Tang, J. 2018. Dry inoculation methods for non-fat milk powder. J. Dairy Science 102:77-86.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Liu, S., Tang, J., Tadapaneni, R., Yang, R., Zhu, MJ. 2018. Exponentially increased thermal resistance of Salmonella spp.. and Enterococcus faecium at reduced water activity. Applied and Environmental Microbiology 84(8):e02742-17.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Tadapaneni, R.K., Xu, J., Yang, R., Tang, J. 2018. Improving design of thermal water activity cell to study thermal resistance of Salmonella in low-moisture foods. LWT-Food Science and Technology 92:371-379.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Taylor, M.H., Tsai, H, Rasco, B., Tang, J., Zhu, M.J. 2018. Stability of Listeria monocytogenes in wheat flour during extended storage and isothermal treatment. Food Control 91:434-439.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Tsai, H.C., Ballom, K.F., Xia, S., Tang, J., Marks, B.P., Zhu, M.J. 2019. Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing. Food Microbiology 82:135-141.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Wei, X., Lau, S. K., Stratton, J., Irmak, S., Bianchini, A., & Subbiah, J. 2018. Radio Frequency Pasteurization Process for Inactivation of Salmonella spp. and Enterococcus faecium NRRL B-2354 on Ground Black Pepper. International Association for Food Protection Annual Meeting, July 8-11, Salt Lake City, UT.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Verma, T. and J. Subbiah. 2018. Use of residence time versus screw speed in the response surface model for microbial inactivation during single-screw extrusion of low-moisture food. International Association for Food Protection Annual Meeting, July 8-11, Salt Lake City, UT.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Subbiah, J. and T. Verma. 2018. Validation of extrusion process for safety of low-moisture food. Conference of Food Engineering, September 9-12, Minneapolis, MN (USA).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chen, L., and Subbiah, J. 2018. Radiofrequency Inactivation of Salmonella spp. in Cumin Seeds. American Society of Agricultural and Biological Engineers (ASABE) Annual Meeting, July 29- August 1, Detroit, MI.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chen, L., Wei, X., and Subbiah, J. 2018 Radiofrequency Inactivation of Salmonella spp. and Enterococcus faecium NRRL B-2354 in Cumin Seeds. International Association for Food Protection (IAFP) Annual Meeting, July 8-11, Salt Lake City, UT.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chen, L., and Subbiah, J. 2018. Radiofrequency Inactivation of Enterococcus Faecium NRRL B-2354 in Cumin Seeds. International Microwave Power Institute (IMPI) Annual Meeting, June 26- 28, Long Beach, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chen, L., Lau, S., Anandappa, A., and Subbiah, J. 2018. Developing a controlled gaseous ozone treatment chamber to evaluate and optimize processing parameters on low-moisture foods. Alliance for Advanced Sanitation Annual Meeting, University of Nebraska-Lincoln, Lincoln, NE.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Hildebrandt I, Marks B. 2018. Factors influencing Salmonella survival kinetics in low-moisture foods during storage. ASABE Paper No. 1801604. Presented at the Annual International Meeting of the American Society of Biological and Agricultural Engineers. Detroit, MI. Jul 29 - Aug 1, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Garc�s-Vega F, Marks B, James M. 2018. Using reliability analysis to assess the utility of non-pathogenic surrogates. Abstract P3-107. Presented at the Annual Meeting of the International Association for Food Protection. Salt Lake City, UT. July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Hildebrandt I, Marks B. 2018. Quantification of statistical power for surrogate-based lethality validation studies. Abstract P3-126. Presented at the Annual Meeting of the International Association for Food Protection. Salt Lake City, UT. July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ahmad N, DSouza RC, Hildebrandt I, Thippareddi H, Marks B, Ryser E. 2018. Validation of Enterococcus faecium NRRL B-2354 as a surrogate for thermal inactivation of Salmonella in date paste. Abstract P2-87. Presented at the Annual Meeting of the International Association for Food Protection. Salt Lake City, UT. July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ahmad N, Oztabak C, Marks B, Ryser E. 2018 Effect of talc on thermal resistance of Enterococcus faecium NRRL B-2354 in almond meal at a water activity of 0.45. Abstract P2-88. Presented at the Annual Meeting of the International Association for Food Protection. Salt Lake City, UT. July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Limcharoenchat P, James M, Hall N, Dolan K, Marks B. 2018. Effects of temperature, water activity, and physical structure on thermal resistance of Salmonella Enteritidis PT30 on multiple almond, date, and wheat products. Abstract P2-91. Presented at the Annual Meeting of the International Association for Food Protection. Salt Lake City, UT. July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Marks BP. 2018. The Low-Moisture Pasteurization Alliance: a multi-institutional collaboration. Presented to the Pet Food Institute Scientific Symposium. Washington DC, Dec 6, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Marks BP. 2018. Modeling pathogen inactivation with multiple dynamic variables and external process factors. Presented at the Microbial Modeling and Risk Analysis Professional Development Group, International Association for Food Protection. Salt Lake City, UT. July 8, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Tang, J. 2018. Engineering Solutions to Control Food Pathogens in Low Moisture Foods. Presented at 2018 Conference of Food Engineering, Minneapolis, MN, Sept. 16-19, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ballom, K. F., H. Tsai., X. Song, J. Tang, and M. J. Zhu. 2018. Thermal stability of Listeria monocytogenes in nonfat dry milk powder. The 2018 Washington Association for Food Protection Annual Meeting, Chelan, Washington, September 20-21, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Taylor, M., H. Tsai, B. Rasco, J. Tang, and M. J. Zhu. 2018. Impact of food matrix and water activity on thermal stability of Listeria monocytogenes in cake-mixes. The 2018 Washington Association for Food Protection Annual Meeting, Chelan, Washington, September 20-21, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Aggarwal A, Keller SE, Halik LA, Grasso-Kelley EM, Anderson NM. 2018. Survival rate of Listeria monocytogenes on sunflower seeds under different storage conditions. Institute of Food Technologists Annual Meeting, Chicago, IL, July 15-18, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chen F, Keller SE, Grasso-Kelley EM, Anderson NM. 2018. Effect of pH on desiccation survival on Salmonella Anatum. Institute of Food Technologists Annual Meeting, Chicago, IL, July 15-18, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Halik L, Suehr Q, Grasso-Kelley EM, Keller SE, Anderson NM. 2018. Comparison of Listeria monocytogenes inactivation on cellulose filter membranes during hot-air roasting. International Association for Food Protection Annual Meeting, Salt Lake City, UT, July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Liu S, Suehr Q, Anderson NM, Grasso-Kelley EM, Keller SE. 2018. Dry transfer of Salmonella in flour or corn meal to food contact surfaces during mixing. Institute of Food Technologists Annual Meeting, Chicago, IL, July 15-18, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Liu X, Suehr Q, Grasso-Kelley EM, Anderson NM. 2018. Inactivation of Enterococcus faecium NRRL B-2354, a surrogate for Salmonella, during baking at different oven relative humidity levels and temperatures. Institute of Food Technologists Annual Meeting, Chicago, IL, July 15-18, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Streufert R, Liu X, Anderson N, Keller SE, Grasso-Kelley EM. 2018. Comparison of the thermal resistance of Salmonella enterica serotypes in peanut butter and soy protein powder. International Association for Food Protection Annual Meeting, Salt Lake City, UT, July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Suehr Q, Keller SE, Anderson NM. 2018. Effectiveness of dry purging for removing Salmonella from a contaminated lab scale auger conveyor system. International Association for Food Protection Annual Meeting, Salt Lake City, UT, July 8-11, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Grasso-Kelley EM. 2018. Microbial methods for challenge studies with case studies and insights. In (S11) The Challenge of Challenge Studies. International Association for Food Protection Annual Meeting, Salt Lake City, UT, July 9, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Keller SE. 2018. Regulatory perspective: Targeting the most resistant pathogen. In (S14) Pathogenic E. coli in low moisture food systems, contamination, survival, and risks. International Association for Food Protection Annual Meeting, Salt Lake City, UT, July 9, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Anderson NM. 2018. Regulatory perspective. In (S11) The Challenge of Challenge Studies. International Association for Food Protection Annual Meeting, Salt Lake City, UT, July 9, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Anderson NM. 2018. Process validation for FSMA. Peanut and Tree Nut Processors Association (PTNPA) Technical Forums, Chicago, IL, July 11-12, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Anderson, NM. 2019. How validation pitfalls translate to inspection citations (483s) and warning letters. Institute for Thermal Processing Specialists (IFTPS) Annual Meeting, San Antonio, TX, February 26-28, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Marks, BP. 2019. Canning vs. baking: Everything you thought you knew about D and z-values. Institute for Thermal Processing Specialists (IFTPS) Annual Meeting, San Antonio, TX, February 26-28, 2019.
  • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Limcharoenchat P. 2018. Product structure and composition affect Salmonella thermal resistance in low-moisture foods. Ph.D. dissertation. Department of Biosystems and Agricultural Engineering. Michigan State University. East Lansing, MI.
  • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Liu X. 2018. Baking validation using Enterococcus faecium as a surrogate for Salmonella. M.S. thesis. Department of Food Science and Nutrition. Illinois Institute of Technology, Chicago, IL.
  • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Liu S. 2018. Evaluation of dry cleaning efficacy for the removal of microbial hazards from food contact surfaces. M.S. thesis. Department of Food Science and Nutrition. Illinois Institute of Technology, Chicago, IL.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Alan, K. S., Subbiah, J., Schmidt, K. A. 2019. Application of a dry heat treatment to enhance the functionality of low-heat nonfat dry milk. Journal of Dairy Science. 102:1096-1107.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Li, Y., Zhou, L., Chen, J., Subbiah, J., Chen, X., Fu, H., Wang, Y. 2018. Dielectric properties of chili powder in the development of radio frequency and microwave pasteurisation. International Journal of Food Properties, 20, S3373-S3384.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Verma, T. , X. Wei, S.K. Lau, A. Bianchini, K.M. Eskridge, and J. Subbiah. 2018. Evaluation of Enterococcus faecium NRRL B?2354 as a Surrogate for Salmonella During Extrusion of Low?Moisture Food. Journal of Food Science, 83: 1063-1072.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wei, X., S.K. Lau, J. Stratton, S. Irmak, A. Bianchini, and J. Subbiah. 2018. Radio-Frequency Processing for Inactivation of Salmonella enterica and Enterococcus faecium NRRL B-2354 in Black Peppercorn. Journal of Food Protection. 8:1685-1695.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Lau, S. K., J. Subbiah. 2018. An automatic system for measuring dielectric properties of foods: Albumen, yolk, and shell of fresh eggs. Journal of Food Engineering, 223:79 - 90.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Verma, T., Wei, X., Lau, S. K., Bianchini Huebner, A., Eskridge, K., Stratton, J., Anderson, N. M., Thippareddi, H., Subbiah, J. 2018. Response Surface Methodology for Salmonella Inactivation During Extrusion Processing of Oat Flour. Journal of Food Protection. 81:815-826.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2019 Citation: Garces-Vega F, Ryser ET, Marks BP. 2019. Relationships of water activity and moisture content to the thermal inactivation kinetics of Salmonella in low-moisture foods. J. Food Prot. In press.
  • Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Ahmad NH, Oztabak C, Marks BP, Ryser ET. 2019. Effect of talc as a dry-inoculation carrier on thermal resistance of Enterococcus faecium NRRL B-2354 in almond meal. J. Food Prot. In press.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Limcharoenchat P, Buchholz SE, James MK, Hall NO, Ryser ET, Marks BP. 2018. Inoculation protocols influence the thermal resistance of Salmonella Enteritidis PT30 in fabricated almond, wheat, and date products. J. Food Prot. 81:606-613.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Casulli KE, Garces-Vega FJ, Dolan KD, Ryser ET, Harris LJ, Marks BP. 2018. Impact of process temperature, humidity, and initial product moisture on thermal inactivation of Salmonella Enteritidis PT30 on pistachios during hot-air heating. J. Food Prot. 81:1351-1356.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Limcharoenchat, P., M. K. James, and B. P. Marks. 2019. Survival and thermal resistance of Salmonella Enteritidis PT 30 on almonds after long-term storage. J. Food Prot. 82:194-199.
  • Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Haendiges J, Keller S, Suehr Q, Anderson N, Reed E, Zheng J, Miller J, Hoffmann M. 2019. Complete genome sequences of five Salmonella enterica strains used in inoculation cocktails in low-moisture food storage studies. Microbial Resource Announcements. (accepted)
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Anderson NM 2018. Recent advances in low moisture food pasteurization. Current Opinion in Food Science. (Published online 22-NOV-2018).


Progress 05/15/17 to 05/14/18

Outputs
Target Audience:Our key stakeholders for this project are: (1) Suppliers of pasteurization equipment for the low-moisture food industry, (2) Dry ingredient suppliers, (3) Processors utilizing or producing ready-to-eat, low-moisture food products, (4) The U.S. Food and Drug Administration (as the relevant regulator), and (5) USDA-NIFA (as the proposed investor in this project). Changes/Problems:There are no changes to the project scope, goals, or overall action plan. What opportunities for training and professional development has the project provided?The entire research team (including undergraduates, and graduate students), across the multiple project sites, has been trained in advanced laboratory techniques necessary for conducting experiments with biosafety level-2 pathogens in low-moisture products, which present specific challenges in ensuring worker safety, particular when working with powdered products. Additionally, the project team presented a a full-day workshop (Validating Pasteurization Processes for Low-Moisture Products) for industry professionals working in the area of low-moisture food safety (July 8, 2017 at the IAFP Annual Meeting, Tampa, FL). The 31 attendees included practicing microbiologists, food scientists, and engineers. Also, the project team presented a mini-workshop (Considerations for Validation of Thermal Processes Used in the Manufacture of Low Moisture Foods) for industry professionals (~31 attendees) at the Process Expo 2017, Chicago, IL. How have the results been disseminated to communities of interest?In addition to peer-reviewed scientific journals, project results were presented at the 2017 Annual Meetings of the International Association for Food Protection (IAFP), Institute of Food Technologists (IFT), the American Society of Agricultural and Biological Engineers (ASABE), and other professional/scientific venues. Additionally, communications with key stakeholder groups has occurred via the project webpage (lowmoisture.egr.msu.edu), the Low-Moisture Task Force at the Institute for Food Safety and Health (IFSH) annual meeting in Chicago (including solicitation of stakeholder input on key priorities for technology purchase decisions), and via the previously mentioned workshop. What do you plan to do during the next reporting period to accomplish the goals?Our Logic Model and Administrative Timeline (in the Management Plan) continue to provide the overall framework for the various activities, outputs, outcomes, and impacts over the course of the entire project. We utilize both of these tools as part of ongoing project management and annual accountability for each section of the project. An overall outline of the year-4 activities is as follows [with the lead co-PDs listed in brackets for each task]: OBJECTIVE 1: a. Conduct in-depth statistical simulations of surrogate-based, commercial-scale validation studies. Conduct meta-analysis of all prior almond industry validation reports [Marks, Anderson, et al.] b. Develop specific validation guidelines for 1-3 technologies [Marks, Anderson, et al.] OBJECTIVE 2: a. Complete pilot-scale challenge studies for multiple gas-based treatments [Subbiah, Zhu, et al., including collaboration with other peer CAP projects] b. Conduct pilot-scale challenge studies for baking processes, with new emphasis on multi-ingredient, formulated products [Grasso-Kelley, Anderson, Marks] c. Collect (from IAG et al.) critical quality factors to be used in future screening of process acceptability for the various test products [Thippareddi, et al.] OBJECTIVE 3: a. Conduct pilot-scale challenge studies for drying processes, including heat/mass/microbial modeling [Jeong, Marks, Grasso-Kelley, et al.] b. Conduct cross-validation of prior nut roasting studies between two laboratories to quantify reproducibility and uncertainty [Grasso-Kelly, Marks, Anderson] c. Test pre-treatment modifications to dry heating processes at the pilot-scale [Jeong, Marks, Grasso-Kelley] OBJECTIVE 4a: a. Complete sector-wide analysis of the economic impacts of low-moisture food recall events [Marks, et al.] b. Complete draft decision framework for technology purchase/adoption decision [Marks, Tang, Gray, Subbiah, Anderson] OBJECTIVE 4b: a. Develop and deliver six new webinars focusing on various aspects of low-moisture pasteurization [Thippareddi, Marks, Anderson, Gray] b. Deliver portion of 1.5-day workshop on low-moisture food products at 2018 Annual Meeting of the Institute of Food Technologists [Marks] c. Deliver one-day in-person workshop at the 2019 meeting the Institute for Thermal Process Specialists (IFTPS) [Anderson, Marks, Tang] OBJECTIVE 4c: a. Improve current promotion of Multi-Location Validation Center and pilot-scale processing capabilities at MSU, WSU, UNL, and IFSH [Jeong, Tang, Subbiah, Grasso, Marks] OBJECTIVE 5: a. Develop 2-3 content modules for beta-testing in graduate courses [Tang, Marks, Subbiah] ASSESSMENT PLAN: Consistent with our proposed strategy, the evaluation effort will focus on output/outcome evaluation during years 4. Our efforts in these areas will use more structured and quantitative methods (e.g., questionnaires and bibliometric analyses) and will assess the extent to which the outcomes specified in our logic model have been produced. Primary data will be collected from significant stakeholder groups, including firms participating on our Industry Advisory Group and participants in the various webinars and workshops [Gray, Thippareddi, Marks] RAPID RESPONSE MINI-PROJECTS: a. The next round of Rapid-Response Mini-Projects will be completed and reported [co-PDs].

Impacts
What was accomplished under these goals? This project aims to enhance development, improvement, commercial adoption, and validation of technologies that ensure microbial safety of low-moisture foods, such as cereal products, nuts, dried fruits, etc. We have made key contributions to both food safety science and practice through research and outreach activities. For example, a five-laboratory study quantified the acceptability of a non-pathogenic surrogate organism (Enterococcus faecium) as a tool to validate thermal processes for reducing Salmonella in six different food products. This type of novel study, cross-validating test results across multiple laboratories, is an especially unique contribution of this CAP project. This is critically important information for equipment suppliers, food processors, and regulators responsible for evaluating efficacy of pathogen reduction processes. The project also has completed significant additional pilot-scale testing of multiple technologies, including radio-frequency, extrusion, and roasting. Again, the major contribution of this collaboration is that each of these technologies are being tested across multiple laboratories, which enables cross-validations, testing of multiple product/process factors, and quantification of process uncertainty. The net result is that findings and recommendations will be more robust, and will improve the reliability of industry practices for validating these technologies. To ensure real-world impact, this project includes significant outreach/training activities. In the past year, this has included multiple workshop and training events (detailed below), in which the project team engaged practicing professionals with the latest research findings and best practices. Additionally, the project team had multiple meetings with our Industry Advisory Group (IAG). The IAG identified a list of "hot topics" in low-moisture food safety not currently addressed by this or other projects. The project team then proposed candidate Rapid Response Mini-Projects, and the IAG selected the highest priority, funded with specific funds set aside in the original project proposal for this purpose. That mini-project quantified the thermal resistance of Listeria monocytogenes in isothermal and radio-frequency systems. There previously was very scarce data characterizing the response of L. monocytogenes in low-moisture foods, and the IAG identified this as an important information gap. This report cannot detail all of the key accomplishments from the current project year, and the reader is encouraged to see the extensive list of project products to find greater details. However, some sample specific accomplishments across the project objectives are listed below. OBJECTIVE 1: The project team continues to be a collective leader in advancing the understanding of how high-temperature water activity is influenced by product composition and affects microbial inactivation. These findings are singularly unique, in that multiple laboratories are using identical custom-designed, high-temperature water activity meters. Again, this type of multi-institutional project has enabled a type of outcome (i.e., cross-validation of results) that simply would not be possible with individual projects, and which will advance the science of validating thermally-based pasteurization technologies. As previously reported, this project also has included an extensive evaluation of a non-pathogenic surrogate organism for commercial process validation. The next step was to quantify the statistical power of this tool, which has not been previously reported. Multiple sampling plans were evaluated for the likelihood of correctly reporting effective or non-effective preventive controls. Using a Monte Carlo-based Bayesian approach, pre- and post- treatment samples were randomly generated and tested (using confidence and prediction intervals, α=0.05) to determine if target lethality was achieved. With true mean lethality ≤ target lethality, all sampling plans achieved ≥99% likelihood of correctly indicating an ineffective treatment. However, using a minimal sampling design on a barely-effective treatment, only 66% of the experiments correctly identified the treatment as effective. The significance of these findings is that statistical power of sampling designs depended on preventative control effectiveness. Additionally, the prediction interval, which heretofore is rarely reported, was the most sensitive metric to evaluate treatment sufficiency, making it an important calculation in validation experiments. OBJECTIVE 2: Significant additional results have been generated across multiple pilot-scale challenge studies, in which Salmonella and/or E. faecium were inoculated into food products - focusing on radio-frequency (RF), extrusion, and roasting in the past year. In each of these studies, microbial inactivation models were developed and compared to pilot-scale results for testing of the surrogate and process effects. For example, thermal inactivation kinetics for Salmonella in corn flour were determined in the laboratory and validated via pilot-scale RF treatments. Similarly, Salmonella-inoculated oat flour was introduced into an extrusion process, and the effects of product formulation (e.g., fat and moisture content) and process conditions (e.g., screw speed and temperature) were modeled to develop a tool that can be used to evaluate the impact of extrusion parameters on process lethality. In another study, the impact of process conditions (i.e., dew point temperature and air velocity) on pathogen and surrogate lethality were quantified in pilot-scale trials for walnut roasting. One key conclusion was that process lethality uncertainty decreased with increasing humidity, which is important for the design of validation studies. The aggregated results from our pilot-scale studies are forming the basis for unified principles and recommendations for designing pasteurization validation studies in commercial applications. OBJECTIVE 3: Additional inoculated studies have been completed with multiple legacy technologies (e.g., roasting, spray drying). In each case, the key outcomes are quantification of the effects of key process variables (e.g., dry bulb temperature, air velocity) on both process lethality and process uncertainty. For example, a study on almond roasting demonstrated that air velocity significantly impacts process lethality independently of the changes caused in product surface temperature. Additionally, the project team presented a symposium at a national conference (IAFP), in which a systems approach to validating legacy processes, and illustrative case studies based on the project research results, were presented to a large audience of food safety professionals. OBJECTIVE 4: The project team delivered one full-day workshop, entitled "Validating Pasteurization Processes for Low-Moisture Products" and one mini-workshop entitled "Considerations for Validation of Thermal Processes Used in the Manufacture of Low Moisture Foods" to industry practitioners (see "Other Products" for details). In immediately post-workshop assessment of the full-day workshop, participants rated the impact/quality, speaker effectiveness, case studies, and overall program between "very good" and "excellent." A six-month post-workshop assessment survey has recently been distributed to evaluate the subsequent impact of the training experience on the attendees' professional practice. ASSESSMENT: Dr. Gray, our evaluation specialist, has participated in all team meetings and used program records and observation to track project activity. Consistent with our "improvement evaluation" strategy, he has also provided feedback on achievement of objectives, facilitated Industry Advisory Group discussions, and provided input on project management. The current year focused on interaction with our IAG and assessment of workshop efficacy and impact.

Publications

  • Type: Journal Articles Status: Awaiting Publication Year Published: 2018 Citation: Verma, T., Wei, X., Lau, S. K., Bianchini Huebner, A., Eskridge, K., Stratton, J., Anderson, N. M., Thippareddi, H., Subbiah, J. 2018. Response Surface Methodology for Salmonella Inactivation During Extrusion Processing of Oat Flour. Journal of Food Protection. In press.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2018 Citation: Limcharoenchat P, Buchholz SE, James MK, Hall NO, Ryser ET, Marks BP. 2018. Inoculation protocols influence the thermal resistance of Salmonella Enteritidis PT30 in fabricated almond, wheat, and date products. Journal of Food Protection. In press.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Xu, J., Liu, S., Song, J., Tang, J., Zhu, M.J., Gray, P., Villa-Rojas, R. 2018. Dry-inoculation method for thermal inactivation studies in wheat flour using freeze-dried Enterococcus faecium NRRL B-2354. LWT-Food Science and Technology, 89: 10-17.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Liu, S., Ozturk, S., Xu, J., Kong, F., Gray, P., Zhu, M.J., Shyam, S.S., and Tang, J. 2018. Microbial validation of radio frequency pasteurization of wheat flour by inoculated pack studies. Journal of Food Engineering, 217:68-74.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Tadapaneni, R.K, Yang R., Carter, B., Tang, J. 2017. A new method to determine the water activity and the net isosteric heats of sorption for low moisture foods at elevated temperatures. Food Research International 102:203-212.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Tadapaneni, R.K., Syamaladevi, R.M., Villa-Rojas, R., Tang, J. 2017. Design of a novel test cell to study the influence of water activity on the thermal resistance of Salmonella in low-moisture foods. J. Food Engineering 208: 48-56.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Xu, J., Liu, S., Tang, J., Ozturk, S., Kong, F., Shah, D.H. 2018. Application of freeze-dried Enterococcus faecium NRRL B-2354 in radio-frequency pasteurization of wheat flour. LWT-Food Science and Technology 90: 124-131.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2018 Citation: Jiao, Y., Tang, J., Wang, Y., Koral, T.Y. 2018. Radio-frequency applications for food processing and safety. Annual Review of Food Science and Technology 9: in press.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Anderson, N.M., S.E. Keller, N. Mishra, S. Pickens, D. Gradl, T. Hartter, G. Rokey, C. Dohl, B. Plattner, S. Chirtel, E.M. Grasso-Kelley. 2017. Salmonella Inactivation during Extrusion of an Oat Flour Model Food. Journal of Food Science. 82: 738743. doi:10.1111/1750-3841.13629
  • Type: Other Status: Published Year Published: 2017 Citation: Anderson, D., N.M. Anderson, J. Barach, T. Egan, C. Fisher, E. Grasso-Kelley, J. Harrington, B. Kottapalli, L. Lucore, B. Marks, S. Perry, G. Rokey, S. Schlegel, R. Suhalim, D. Whitman. 2016. Validating the Reduction of Salmonella and other Pathogens in Heat Processed Low-Moisture Foods: Spotlight on Baking. OpX Leadership Network, PMMI. (Industry Guidance Document )
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Lau S.K, Thippareddi H., Subbiah J. 2017. A Novel Method to Determine Thermal Death Kinetics of Microorganisms in Low Moisture Foods: Thermal-Death-Time Sandwich. Presented at the IAFP 2017 Annual Meeting, Jul 9-12, Tampa, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Verma T., Subbiah J., Bianchini A., Stratton J., Wei X., Lau S.K., Thippareddi H., Anderson N., Eskridge K. 2017. Validation of Extrusion Processing As an Inactivation Step for Salmonella in Low-Moisture Food. Presented at the IAFP 2017 Annual Meeting, Jul 9-12, Tampa, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Xu, J., Tang, J., Zhu, MJ., and Liu, S. 2017. Development of a dry inoculation method using freeze-dried Enterococcus faecium NRRL B-2354 for microbial thermal inactivation in low moisture foods. The 2017 Institute of Food Technologists Annual Meeting, Las Vegas, Nevada, June 25-28, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu, S., Tadapaneni, RK. Zhu, MJ., Shyam, SS., and Tang, J. (2017). Heat resistance of Salmonella and Enterococcus faecium increased exponentially at reduced water activity in silicon dioxide. The 2017 International Association for Food Protection Annual Meeting, Tampa, Florida, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Marks, BP. 2017. Challenges in food engineering education and research. Presented at the Annual International Meeting of the American Society of Agricultural and Biological Engineers. Spokane, WA. July 16-19, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Casulli, K, Dolan KD, Marks BP. 2017. Evaluation of process validation methods for Salmonella inactivation in pistachios. IFT Abstract 01-029. Presented at the Annual Meeting of the Institute of Food Technologists. Las Vegas, NV. June 25-28, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Marks BP. 2017. Modifying Existing (Legacy) Thermal processes to achieve pathogen reduction goals. Symposium S45. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hildebrandt I, Marks B. 2017. Optimal isothermal data collection practices for estimating microbial thermal inactivation parameters. Abstract P1-150. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Garces-Vega F, Marks BP. 2017. Can adsorption-desorption state affect Salmonella thermal inactivation kinetics in low-moisture foods? Abstract T6-06. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ahmad N, Hildebrandt I, Pickens S, Lau SK, Xu J, Liu S, Tsai HC, Rincon AM, Subbiah J, Thippareddi, H, Zhu M, Tang J, Anderson N, Grasso-Kelley E, Ryser E, Marks B. 2017. Utilization of E. faecium as a Salmonella surrogate for thermal treatment in selected low-moisture food products. Abstract T6-12. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ahmad N, Tsai HC, Hildebrandt I, Zhu M, Tang J, Marks B, Ryser E. 2017. Validation of Enterococcus faecium as a Salmonella surrogate in thermal treatment of almond meal. Abstract P3-02. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hildebrandt I, Pickens S, Lau SK, Subbiah J, Anderson N, Marks B, Grasso-Kelley E. 2017. Multi-laboratory comparison of thermal resistance of Enterococcus faecium and Salmonella enterica in peanut butter. Abstract P3-05. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu S, Ahmad N, Xu J, Hildebrandt I, Ryser E, Zhu M, Marks B, Tang J. 2017. Enterococcus faecium as a surrogate for Salmonella in thermal treatment of non-fat milk powder. Abstract P3-07. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Garces-Vega F, Casulli K, Marks B. 2017. The effect of process air velocity, humidity, and product moisture on Salmonella inactivation on almonds. Abstract P3-08. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Schwartz R, Williams J, Limcharoenchat P, Hall N, James M, Marks B. 2017. Effect of temperature, water activity, and structure on Salmonella thermal resistance in multiple wheat products. Abstract P3-09. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Steinbrunner P, Limcharoenchat P, Marks B, Jeong S. 2017. Effect of long-term almond storage on survival and resistance of Salmonella to heat and x-ray. Abstract P3-12. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tsai HC, Song X, Tang J, Marks B, Zhu M. 2017. Is Enterococcus faecium an appropriate surrogate for Salmonella in thermal process validation of cocoa powder? Abstract P3-14. Presented at the Annual Meeting of the International Association for Food Protection. Tampa, FL. July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Casulli KE, Marks BP, Dolan KD. 2017. On the use of the Weibull model for microbial inactivation in multi-variable dynamic systems. Abstract 15A. Presented at the 9th International Conference on Inverse Problems in Engineering. University of Waterloo. May 23-26, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu, S., Tang, J. 2017. The effect of water activity on thermal resistances of Salmonella enterica and Enterococcus faecium in wheat flour. Annual Meeting of American Association of Cereal Chemists International, San Diego, USA, October 8-11, 2017. (Invited Speaker as winner of 2nd place Graduate Student Research Paper Competition).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu, S., Ahmad, N.H., Xu, J., Ryser, E.T, Zhu, M.J., Marks, B.P., Tang, J. 2017. Enterococcus faecium as a surrogate of Salmonella in isothermal treatment of non-fat milk powder. Poster Presentation, Annual Meeting of International Association for Food Protection, Tampa, Florida, USA, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Xu, J., Liu, S., Tang, J. 2017. Using freeze-dried Enterococcus feacium NRRL B-2354 as a surrogate of Salmonella to validate Radio-frequency pasteurization for low moisture foods. Oral presentation. Annual Meeting of American Society of Agricultural and Biological Engineers (ASABE). Spokane, WA, USA, July 16-19, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Anderson N.M. 2017 Impact of Temperature Dependence of Water Activity on Salmonella Inactivation in a Multicomponent Food System. 7th Annual Food and Veterinary Medicine Science and Research Conference, College Park, MD, October 17-18, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Anderson N.M. 2017. Validating Pathogen Reduction in a Legacy Processes for Low-moisture Foods. Process Expo, Chicago, IL, September 16-17, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Grasso-Kelley E.M. 2017. Utilization of Enterococcus faecium NRRL B-2354 as a Salmonella Surrogate for Validating Isothermal Processing of Low-Moisture Foods Process Expo, Chicago, IL, September 16-17, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Marks B.P. 2017. Modifying Legacy Thermal Processes to Achieve Pathogen Reduction Goals. Process Expo, Chicago, IL, September 16-17, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Subbiah J. 2017. Validation of Radiofrequency Processing for Pasteurization of Low Moisture Foods. Process Expo, Chicago, IL, September 16-17, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Anderson N.M. 2017. A Systems Approach to Validating Pathogen Reduction in a Legacy Process for Low-moisture Foods. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Subbiah J. 2017. When Existing Legacy Processes are Insufficient: What are the Novel Dedicated Technology Options? International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Anderson NM, Luo Y, Grasso-Kelley E. Impact of Temperature Dependence of Water Activity on Salmonella Inactivation in a Multicomponent Food System. 7th Annual Food and Veterinary Medicine Science and Research Conference, College Park, MD, October 17-18, 2017. (selected for oral presentation, FDA Public Health Impact Award)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Suehr, Q, Anderson N, Keller, S. Thermal Resistance of Shiga-toxin-producing Escherichia coli O121 in Wheat Flour. 7th Annual Food and Veterinary Medicine Science and Research Conference, College Park, MD, October 17-18, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu S, Anderson N, Keller S: Evaluation of Dry Transfer in the Removal of Salmonella from Food Contact Surfaces. I7th Annual Food and Veterinary Medicine Science and Research Conference, College Park, MD, October 17-18, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hildebrandt I, Pickens S, Lau SK, Subbiah J, Anderson N, Marks B, Grasso-Kelley E. Multi-Laboratory Comparison of Thermal Resistance of Enterococcus faecium and Salmonella Enterica in Peanut Butter. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Anderson NM, Luo Y, Grasso-Kelley E. Impact of Temperature Dependence of Water Activity on Salmonella Inactivation in a Multicomponent Food System. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu S, Anderson N, Keller S. Evaluation of Dry Transfer in the Removal of Salmonella from Food Contact Surfaces. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liu, X, Suehr, Q, Grasso-Kelley, EM, Anderson, NM. Suitability of Enterococcus faecium as a Surrogate for Salmonella in Soy Protein Powder. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Wang W, Anderson NM, Pickens S, Hildebrandt I, Grasso-Kelley E. Validation of Baking to Inactivate Salmonella in Model High-Protein and High-Fat Foods. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Verma T, Subbiah J, Bianchini A, Stratton J, Wei X, Lau SK, Thippareddi H, Anderson N, Eskridge K. Validation of Extrusion Processing As an Inactivation Step for Salmonella in Low-Moisture Food. International Association for Food Protection Annual Meeting, Tampa, FL, July 9-12, 2017.
  • Type: Book Chapters Status: Published Year Published: 2017 Citation: Grasso-Kelley, E.M., Kataoka, A., Lucore, L. 2017. Chapter 3: Potential Sources and Risk Factors, In Control of Salmonella and Other Bacterial Pathogens in Low Moisture Foods. Ed R. Podolak, G. Black. John Wiley & Sons Ltd., West Sussex, UK.
  • Type: Book Chapters Status: Published Year Published: 2017 Citation: Lucore, L., Kataoka, A., Anderson, D., Grasso-Kelley, E.M. 2017. Chapter 5: Best Industry Practices to Control Salmonella in Low Moisture Foods, In Control of Salmonella and Other Bacterial Pathogens in Low Moisture Foods. Ed R. Podolak, G. Black. John Wiley & Sons Ltd., West Sussex, UK.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Garces-Vega FJ. 2017. Quantifying water effects on thermal inactivation of Salmonella in low-moisture foods. Ph.D. dissertation. Department of Biosystems and Agricultural Engineering. Michigan State University. East Lansing, MI.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Ravi Kiran Tadapaneni, November, 2017. Influence of Water Activity on the Thermal Resistance of Salmonella in Low Moisture Foods. Ph.D. Dissertation. Department of Biological Systems Engineering, Washington State University, Pullman, WA.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Shuxiang Liu, December 2017, Study of Enterococcus faecium NRRL B2354 as Surrogate of Salmonella in Low-moisture Foods and Its Use in Validation of Radio Frequency Pasteurization. Ph.D. Dissertation. Department of Biological Systems Engineering, Washington State University, Pullman, WA.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Verma, T. 2017. Validation of Extrusion Processing for the Safety of Low-Moisture Foods. M.S. Thesis. Department of Food Science & Technology. University of Nebraska-Lincoln, Lincoln, NE.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Wei, X, 2017. Radiofrequency processing for inactivation of Salmonella spp. and Enterococcus faecium NRRL B-2354 in whole black peppercorn and ground black pepper. M.S. thesis. University of Nebraska-Lincoln, Lincoln, NE.
  • Type: Other Status: Published Year Published: 2017 Citation: Grasso-Kelley, E.M. 2017. Control of pathogens in low water activity foods. American Institute of Chemical Engineers, webinar series. December 14, 2017.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Wang, W. 2017. Validation of baking to inactivate Salmonella in high-protein and high-fat model foods. M.S. Thesis. Department of Food Science and Nutrition. Illinois Institute of Technology. Chicago, IL.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Luo, Y. 2017. Impact of temperature dependence on water activity on Salmonella inactivation in a multicomponent food system. M.S. Thesis. Department of Food Science and Nutrition. Illinois Institute of Technology. Chicago, IL.


Progress 05/15/16 to 05/14/17

Outputs
Target Audience:Our key stakeholders for this project are: (1) Suppliers of pasteurization equipment for the low-moisture food industry, (2) Dry ingredient suppliers, (3) Processors utilizing or producing ready-to-eat, low-moisture food products, (4) The U.S. Food and Drug Administration (as the relevant regulator), and (5) USDA-NIFA (as the proposed investor in this project). Changes/Problems:There are no changes to the project scope, goals, or overall action plan. What opportunities for training and professional development has the project provided?The entire research team (including undergraduates, and graduate students), across the multiple project sites, has been trained in advanced laboratory techniques necessary for conducting experiments with biosafety level-2 pathogens in low-moisture products, which present specific challenges in ensuring worker safety, particular when working with powdered products. Additionally, the project team presented a webinar for industry professionals working in the area of low-moisture food safety (May 18, 2016). The attendees (n=72) included practicing microbiologists, food scientists, and engineers. The webinar title was "Understanding the Effects of Water (Activity, Content, Humidity) on Thermal Inactivation of Salmonella in Low-Moisture Food Systems. May 18, 2016." How have the results been disseminated to communities of interest?Project results were presented at the 2016 Annual Meetings of the International Association for Food Protection (IAFP), Institute of Food Technologists (IFT), the American Society of Agricultural and Biological Engineers (ASABE), and other professional/scientific venues. Additionally, communications with key stakeholder groups has occurred via the project webpage (lowmoisture.egr.msu.edu), the Low-Moisture Task Force at the Institute for Food Safety and Health (IFSH) annual meeting in Chicago (including solicitation of stakeholder input on key priorities for technology purchase decisions), and via the previously mentioned webinar. What do you plan to do during the next reporting period to accomplish the goals?Our Logic Model and Administrative Timeline (in the Management Plan) continue to provide the overall framework for the various activities, outputs, outcomes, and impacts over the course of the entire project. We utilize both of these tools as part of ongoing project management and annual accountability for each section of the project. An overall outline of the year-3 activities is as follows [with the lead co-PDs listed in brackets for each task]: OBJECTIVE 1: a. a. Complete non-pathogenic surrogate (E. faecium) testing to compare resistance to Salmonella (5-strain cocktail) in six representative product matrices (across multiple labs) [Grasso-Kelley, Ryser, Zhu, Thippareddi]. B. Develop statistical guidance for utilization of the surrogate in commercial process validations [Marks, Anderson, et al.]. c. Develop outline of pasteurization validation guidelines, with input from IAG [Marks, Anderson, Gray]. OBJECTIVE 2: a. Complete pilot-scale challenge studies for radio-frequency, extrusion, spray drying, and roasting [Tang, Subbiah, Jeong, Marks]. b. Conduct pilot-scale challenge studies for baking and drying processes [Grasso-Kelley, Anderson, Marks]. c. Collect (from IAG et al.) critical quality factors to be used in future screening of process acceptability for the various test products [Thippareddi, et al.]. d. Develop and publish SOPs for conducting and reporting pilot-scale challenge studies with low-moisture foods [Subbiah, Jeong, Marks, Anderson]. OBJECTIVE 3: a. Develop and publish suggested control and monitoring strategies to enhance efficacy of legacy technologies as pathogen-reduction steps [Marks, Anderson]. b. Test multiple process modifications to dry heating processes (e.g., roasting, drying, baking) at the pilot-scale [Marks, Grasso-Kelley]. OBJECTIVE 4a : a. Propose outline of decision heuristics for technology purchase/adoption decision [Marks, Tang, Gray, Subbiah, Anderson]. b. Quantify estimates of capital and operating costs for the various technologies being considered (with help of IAG members) [Subbiah, Marks, Tang]. OBJECTIVE 4b: a. Develop and deliver six new webinars focusing on various aspects of low-moisture pasteurization [Thippareddi, Marks, Anderson, Gray]. b. Offer one-day workshop on low-moisture pasteurization validation at 2017 Annual Meeting of the International Association for Food Protection [Marks, Anderson, Thippareddi, Gray, Grasso-Kelley]. OBJECTIVE 4c: a. Promote Multi-Location Validation Center and pilot-scale processing capabilities at MSU, WSU, UNL, and IFSH [Jeong, Tang, Subbiah, Grasso, Marks]. OBJECTIVE 5: a. Develop 2-3 content modules for beta-testing in graduate courses [Tang, Marks, Subbiah]. ASSESSMENT PLAN: Consistent with our proposed strategy, the evaluation effort will begin to focus on output/outcome evaluation during years 3-4. Our efforts in these areas will use more structured and quantitative methods (e.g., questionnaires and bibliometric analyses) and will assess the extent to which the outcomes specified in our logic model have been produced. Primary data will be collected from significant stakeholder groups, including firms participating on our Industry Advisory Group [Gray, Thippareddi, Marks]. RAPID RESPONSE MINI-PROJECTS: a. The first round of Rapid-Response Mini-Projects will be completed and reported [co-PDs].

Impacts
What was accomplished under these goals? This project aims to enhance development, improvement, commercial adoption, and validation of technologies that ensure microbial safety of low-moisture foods, such as cereal products, nuts, dried fruits, etc. In the current year, we have made key contributions to both food safety science and practice. For example, a cross-laboratory study demonstrated that Salmonella thermal resistance studies were reproducible across five laboratories, but that strict experimental controls and standard operating procedures were essential. A similar study is evaluating how well a non-pathogenic surrogate organism (Enterococcus faecium) mimics the thermal response of Salmonella in six different food products across five laboratories. Ultimately, both of these studies will help ensure greater certainty when testing food safety outcomes for commercial technologies and processes. The project also has completed pilot-scale testing of multiple technologies (with Salmonella and actual food products), including radio-frequency, extrusion, baking, roasting, and spray drying. In each study, the effects of process and product properties were quantified, in terms of pathogen reduction and associated variability. A significant benefit of conducting multiple such studies under the overall collaborative project will be the generation of general guidelines for such tests. This will enhance reliability of industry practices for validating food safety processes, and improve regulators' capacity to evaluate these processes to ensure the microbial safety of our nation's food supply. To ensure real-world impact, this project includes significant outreach and training activities. To date, this has included multiple webinars, with the project team directly communicating new knowledge and best practices to industry scientists and engineers. In the coming year, an in-person workshop will enable in-depth training of professionals, and a webinar series will be offered both live and recorded (via the project webpage - lowmoisture.egr.msu.edu) to multiply impact across the food industry. To ensure continuing relevance of project activities, our Industry Advisory Group consists of twelve management-level engineers and scientists representing technology and service providers, ingredient suppliers, and food manufacturers. Our Industry Advisory Group has identified priority training and research needs, including Rapid-Response Mini-Projects that the project team is pursuing to fill knowledge gaps and meet emerging research needs not initially included in the project work plan. Further details about accomplishments across the project objectives are listed below. OBJECTIVE 1: The reproducibility of Salmonella thermal resistance results were tested across six independent research groups. The D80C values for Salmonella Agona in oat flour at 0.45 water activity (aw) were 28.7, 29.7, 30.8, 32.2, 30.3, and 20.0 min. Although shipping, heating medium, and treatment vessel did not significantly affect the D80C values, one laboratory yielded a lower D80C value (P<0.05). Potential root causes were identified and incorporated into standard operating procedures (SOPs). However, the results demonstrated a generally high degree of reliability, with D80C relative errors ranging from 2.3 to 5.8%. This study has demonstrated the feasibility for highly reproducible results across multiple laboratories, but also has reinforced the importance of strictly following experimental controls and SOPs. In another study, thermal resistances of E. faecium and a five-strain Salmonella cocktail (Agona, Enteritidis, Tennessee, Montevideo, and Mbandaka) are being compared in six representative low-moisture foods, across five different laboratories. Salmonella showed lower (P<0.05) thermal resistance than E. faecium in almond meal, peanut butter, and non-fat dried milk powder. E. faecium and Salmonella showed less thermal resistance in almond meal than in peanut butter, in spite of similar fat contents. Overall, E. faecium appears to be a robust surrogate for Salmonella across multiple low-moisture products; however, product characteristics significantly impact that relationship. It is therefore necessary to consider product composition when validating thermal processes for low aw foods. Based on the results of both of these studies, the project team now is disseminating SOPs (for product inoculation and treatment) to peer research groups outside this project team, which will enhance of the comparability and therefore value of low-moisture food safety research nationally. OBJECTIVE 2: Significant results have been generated across multiple pilot-scale challenge studies, in which Salmonella and/or E. faecium were inoculated into food products and subjected to various technologies and processes in Biosafety Level-2 pilot plants. For example, wheat flour was inoculated and subjected to radio-frequency (RF) treatments in a pilot-scale system. Overall, the results demonstrated the surrogate validity, the effectiveness of an inoculated pack protocol, and conservative validations of pathogen lethality by both model prediction and surrogate outcomes. In an extrusion study, an inoculated oat-flour/oil-based product was processed in a single-screw extruder at three temperatures, screw speeds, moisture contents, and fat contents. A response-surface model reflected decreasing lethality with increasing fat content and decreasing moisture content. The results also demonstrated greater reduction of Salmonella than E. faecium across all treatment, which provides further support of E. faecium as a robust surrogate across multiple technologies. These aggregate results across various technologies and processes are significantly important in providing the food industry required scientific data to support the use of the surrogate for safe and reliable commercial process validations. OBJECTIVE 3: Additional inoculated studies have been completed with multiple legacy technologies (e.g., baking, roasting, spray drying). All three demonstrated significant impact of process conditions on pathogen lethality. Both the baking (biscuit/cracker) and roasting (pistachio) projects demonstrated that process humidity significantly enhances pathogen lethality (P<0.05). Additionally, the baking study also indicated decreased pathogen lethality with increased fat content in the product. Importantly, the baking study also demonstrated that the "cold-spot" is not necessarily the least-lethal spot in a thermally-processed product, as drying of the product surface can impede pathogen inactivation. This is a significantly important result for the industry to incorporate in process validation plans, because a traditional approach focused on the "cold-spot" in a process might overestimate actual pathogen lethality. OBJECTIVE 4: The project team delivered one webinar in the current project year, entitled "Understanding the Effects of Water (Activity, Content, Humidity) on Thermal Inactivation of Salmonella in Low-Moisture Food Systems," hosted by a member of our Industry Advisory Group. Out of 119 pre-registered attendees, 72 attended the event live; the group included food scientists, microbiologists, engineers, and chemists. ASSESSMENT: In addition to stated objectives, our proposal committed to systematic and multidisciplinary performance evaluation. Consistent with our evaluation plan and logic model, the first phase has focused on monitoring and formative evaluation. Dr. Gray, our evaluation specialist, has participated in all team meetings and used program records and observation to track project activity. Consistent with our "improvement evaluation" strategy, he has also provided feedback on achievement of various objectives. Feedback in the current year focused on engagement and interaction with our Industry Advisory Group.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Hildebrandt IM, Marks BP, Ryser ET, Villa-Rojas R, Tang J, Garces-Vega FJ, Buchholz SE. 2016. Effects of inoculation procedures on variability and repeatability of thermal resistance of Salmonella in wheat flour. Journal of Food Protection. 79:1833-1839.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2017 Citation: Huang, Z., Marra, F., Subbiah, J., Wang, S. (2017). Computer simulation for improving radio frequency (RF) heating uniformity of food products: a review. Critical reviews in food science and nutrition. In press.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Boreddy, S.R., H. Thippareddi, G. Froning, and J. Subbiah. 2016. Novel radiofrequency-assisted thermal processing improves the gelling properties of standard egg white powder. Journal of Food Science, 81 (3): E665-E671.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Boreddy, S.R. and J. Subbiah. 2016. Temperature and moisture dependent dielectric properties of egg white powder. Journal of Food Engineering, 168: 6067.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Hildebrandt, I.M., Anderson, N.M., Limcharoenchat, P., Hall, N., Xu, J., Zhu, M., Marks, B.P., Tang, J., Grasso-Kelley, E.M. 2016. Quantifying reproducibility of Salmonella thermal resistance through a multiple inter-laboratory comparison. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Marks BP. 2016. Validating legacy processing systems: application of thermal resistance data and models to predict log reductions in dynamic processes. Symposium 096. Presented at the Annual Meeting of the Institute of Food Technologists. July 19, 2016. Chicago, IL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Casulli KE, Dolan KD, Marks BP. 2016. Performance of Enterococcus faecium as a nonpathogenic surrogate for Salmonella during pistachio roasting. Abstract 17. Presented at the Conference on Food Engineering. Columbus, OH. September 12-14, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Casulli, KE, Garces-Vega FJ, Dolan KD, Marks BP. 2016. Impact of temperature, moisture, and humidity on thermal inactivation of Salmonella in pistachios heated under dynamic processing conditions. Presented at the XIII Latin American Congress of Microbiology and Food Hygiene. September 27-30, 2016. Medell�n, Colombia.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Harris LJ and Marks BP. 2016. The impact of water and product composition on pathogen survival and inactivation. Symposium S21. Presented at the IAFPs European Symposium on Food Safety. 11-13 May 2016. Athens, Greece.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Pickens, S., Burbick, S., Jin, Y., Hildebrandt, I., Grasso-Kelley, E.M., Keller, S.E., Anderson, N.M. 2016. Thermal resistance of Salmonella enterica in a high protein matrix at varying water activities. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Jin, Y., Burbick, S., Pickens, S., Hildebrandt, I., Keller, S.E., Anderson, N.M., Grasso-Kelley, E.M. 2016. Thermal inactivation of Salmonella Agona in a high-fat matrix as influenced by water activity. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Luo, Y., Grasso-Kelley, E.M., Anderson, N.M. 2016. Impact of macronutrients on the temperature dependence of water activity in a multicomponent food system. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wang, W., Anderson, N.M., Hildebrandt, I., Grasso-Kelley, E.M. 2016. Inactivation of Salmonella during baking a high-protein model food. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zhang, J., Hildebrandt, I.M., Grasso-Kelley, E.M., Keller, S.E., Anderson, N.M. 2016. Performance comparison of aluminum test cells and glass vials for determining heat resistance in low-moisture foods. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Garces-Vega, F., Marks, B.P. 2016. Evaluation of water content as a convenient metric in thermal inactivation modeling for low-moisture foods. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Casulli K, Garces-Vega F, Dolan K, Harris LJ, Marks B. 2016. Modeling the effect of product temperature, moisture, and process humidity on thermal inactivation of Salmonella in pistachios. Abstract P2-19. Presented at the Annual Meeting of the International Association for Food Protection. July 31  Aug 3, 2016. St. Louis, MO.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Limcharoenchat, P., James, M., Hall, N., Marks, B. 2016. Moisture equilibration and product fabrication methods affect measured thermal resistance of Salmonella Enteritidis PT30 on/in whole almonds, almond meal, and almond butter. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Liu, S., Syamaladevi, R., Zhu, M.J., Tang, J. 2016. Isothermal inactivation of Salmonella and Enterococcus faecium in dates impacted by water activity variation at elevated temperature. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Xu, J., Syamaladevi, R., Liu, S., Tadapaneni, R.K., Tang, J., Zhu, M.J., Devendra, S. 2016. Evaluation of thermal resistance of Enterococcus faecium NRRL B-2354 in wheat flour and peanut butter using both TAC and TDT cells. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Syamaladevi, R.M., Tang, T. Tadapaneni, R.V., Villa-Rojas, R., Sablani, S., Carter, B. 2016. Factors influencing the thermal resistance of microorganisms in low moisture foods: importance of water activity. American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Tadapaneni, R.K., Syamaladevi, R.M., Tang, T. Villa-Rojas, R. 2016. Study of thermal resistance of Salmonella in low moisture foods inside a closed system maintained with stable water activity at the elevated temperatures. Annual Meeting of American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Liu, S., Zhu, Z., Tang, J., Zhu, M. J. 2016. Validation of radio frequency-assisted pasteurization in low-moisture foods using Enterococcus faecium. Annual Meeting of American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Xu, J., Liu, S., Tang, J., Zhu, M.J., Devendra, S.H. 2016. Evaluation of thermal resistance of fresh and freeze-dried Enterococcus faecium NRRL B-2354 in wheat flour using both TAC and TDT cells. Annual Meeting of American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Lau S.K., Subbiah J. 2016. Design of a Dielectric Properties Test Cell. Presented at the IMPI 50th Annual Microwave Power Symposium  June 21-23, 2016  Orlando, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Lau S.K., Vasquez S., Wei X., Stratton J., Bianchini A., Thippareddi H., Subbiah J. 2016. Development of a new thermal death time method: TDT blocks. Presented at the CoFE 2016 Meeting  September 12-14, 2016  Columbus, OH.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Lau S.K., Irmak S., Subbiah J. 2016. Radiofrequency pasteurization of peanut butter: quality evaluation. Presented at the IAFP 2016 Annual Meeting  July 31-August 3, 2016  St. Louis, MO.
  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Casulli KE. 2016. Improving pathogen-reduction validation methods for pistachio processing. M.S. thesis. Department of Biosystems and Agricultural Engineering. Michigan State University. East Lansing, MI.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Jeong S., Marks BP, James MK. 2017. Comparing thermal process validation methods for Salmonella inactivation on almond kernels. Journal of Food Protection. 80:169-176.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Villa-Rojas R, Zhu MJ, Marks BP, Tang J. 2017. Radiofrequency inactivation of Salmonella Enteritidis PT30 and Enterococcus faecium in wheat flour at different water activities. Biosystems Engineering. 156:7-16.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Smith DF, Hildebrandt IM, Casulli KE, Dolan KD, Marks BP. 2016. Modeling the effect of temperature and water activity on the thermal resistance of Salmonella Enteritidis PT30 in wheat flour. Journal of Food Protection. 79:2058-2065.


Progress 05/15/15 to 05/14/16

Outputs
Target Audience:Our key stakeholders for this project are: (1) Suppliers of pasteurization equipment for the low-moisture food industry, (2) Dry ingredient suppliers, (3) Processors utilizing or producing ready-to-eat, low-moisture food products, (4) The U.S. Food and Drug Administration (as the relevant regulator), and (5) USDA-NIFA (as the proposed investor in this project). Changes/Problems:There are no changes to the project scope, goals, or overall action plan. The only change of note was the administrative delay in the release of year-1 funding, such that year-1 funding was not available until approximately four months into the project year, which delayed the start of some project tasks and associated expenditures. However, it is fully anticipated that project tasks and outcomes will be on track as planned in year two. What opportunities for training and professional development has the project provided?The entire research team (including undergraduates, and graduate students), across the multiple project sites, has been trained in advanced laboratory techniques necessary for conducting experiments with biosafety level-2 pathogens in low-moisture products, which present specific challenges in ensuring worker safety, particular when working with powdered products. How have the results been disseminated to communities of interest?Initial research results have been submitted to and will be presented at the 2016 Annual Meetings of the International Association for Food Protection (IAFP), Institute of Food Technologists (IFT), and the American Society of Agricultural and Biological Engineers (ASABE). Additionally, communications with key stakeholder groups has occurred via the Low-Moisture Task Force at the IFSH annual meeting in Chicago (including solicitation of stakeholder input on key priorities for technology purchase decisions), and via the previously mentioned mini-workshop presented at the 2015 Process Expo in Chicago. What do you plan to do during the next reporting period to accomplish the goals?Our Logic Model and Administrative Timeline (in the Management Plan) continue to provide the overall framework for the various activities, outputs, outcomes, and impacts over the course of the entire project. We utilize both of these tools as part of ongoing project management and annual accountability for each section of the project. An overall outline of the year-2 activities is as follows [with the lead co-PDs listed in brackets for each task]: OBJECTIVE 1: a. Complete non-pathogenic surrogate (E. faecium) testing to compare resistance to Salmonella (5-strain cocktail) in six product matrices (and validate at multiple labs) [Ryser, Zhu, Grasso, Thippareddi]. b. Meet with IAG to identify key attributes of validation protocols [Marks, Anderson, Gray]. c. Develop two example "Quick guides" for applying validation guidelines (roasting and baking) [Marks, Anderson, Thippareddi]. OBJECTIVE 2: a. Initiate pilot-scale moist-heat and RF challenge studies across two locations each [Tang & Subbiah; Jeong & Grasso]. b. Set-up and initiate dry-heat studies (2nd-half of yr) across two locations [Marks, Grasso]. c. Collect (from IAG et al.) critical quality factors to be used in future screening of process acceptability for the various test products [Thippareddi, et al.]. OBJECTIVE 3: a. Test process modifications (e.g., stage-1 water or humidity) to dry heating processes (e.g., roasting, drying, baking) at the pilot-scale [Marks, Grasso]. OBJECTIVE 4a : a. Collect information from Industry Advisory Group (IAG) et al. to characterize decision heuristics for technology purchase/adoption decision [Marks, Tang, Gray, Subbiah, Anderson]. b. Quantify estimates of actual capital and operating costs for the various technologies being considered (with help of IAG members) [Marks, Tang, Subbiah]. OBJECTIVE 4b: a. Develop content for two webinars focusing on (i) pasteurization technology options and (ii) basic statistics supporting validation methods and decisions [Thippareddi, Marks, Anderson, Gray]. b. Develop workshop/training content for 2017 in-person and/or virtual workshop offerings [Thippareddi, Gray, Marks, Anderson, et al.]. OBJECTIVE 4c: a. Develop initial inventory of pilot-scale processing capabilities at MSU, WSU, UNL, and IFSH, and set-up public-facing web presence [Jeong, Tang, Subbiah, Grasso, Anderson]. OBJECTIVE 5: a. Conduct "market analysis" for graduate learning modules in this space (via peer academic network) [Tang, Marks, Gray, Subbiah]. b. Generate list of modules and learning outcomes [Marks, Tang, Subbiah]. c. Develop 1-3 prototype modules for pilot testing [Tang, Marks, Subbiah]. ASSESSMENT PLAN: a. Develop and validate instruments for project monitoring and formative evaluation functions [Gray, Thippareddi, Marks]. b. Develop and validate instruments for assessing baseline conditions (knowledge and practice) in the low-moisture pasteurization sector [Gray, Thippareddi, Marks]. RAPID RESPONSE MINI-PROJECTS: a. IAG identifies priority activities for Year 2 Rapid-Response Mini-Projects (in Q1, Y2) [Marks, Tang, Thippareddi, Anderson].

Impacts
What was accomplished under these goals? Although the official start date for this project was May 15, 2015, the funding was not actually awarded/released until late August 2015. Therefore, this progress report covers an actual activity period of approximately 5-6 months of project start-up and activity initiation. However, several key first steps have been completed, particularly in conducting an initial cross-laboratory collaborative study and an initial outreach/training program. Initial research results have demonstrated the importance of quantitatively understanding real-world variability in microbial inactivation data and test results, which ultimately affect the reliability of process validations and will affect the required degree of certainty in documenting process and technology efficacy. Additionally, initial interactions with stakeholders, both in information gathering and workshop settings, have confirmed the urgent need for development and dissemination of standard validation protocols, and related tools, for pathogen reduction processes with low-moisture foods. This project is aimed directly at meeting those needs, which is a prerequisite to enhancing the development and implementation of pasteurization technologies and processes in the low-moisture food industry sector. Specific example accomplishments are detailed below. OBJECTIVE 1: One of the critical steps in ensuring reliable process validations is quantifying sources of uncertainty in the microbial inactivation data used to develop and apply lethality models and/or nonpathogenic surrogates to process validations. Before we can develop and implement standardized protocols for validation of low-moisture pasteurization processes/technologies, we need to quantify variability and uncertainty across our own laboratories, in order to quantify the expected robustness of such methods in real-world applications. Therefore, the first two foundational studies in this project were/are aimed at evaluating and/or standardizing these protocols for: (a) determining Salmonella thermal activation parameters for low-moisture products, and (b) quantifying the validity of the nonpathogenic surrogate Enterococcus faecium across a range of low-moisture products. In the first study, four independent laboratories, at the Food and Drug Administration (FDA), Illinois Institute of Technology (IIT), Michigan State University (MSU), and Washington State University (WSU), conducted a cross-laboratory study to quantify reproducibility of Salmonella thermal resistance data. Salmonella Agona lawn cultures were harvested using peptone water and inoculated into three batches of oat flour via liquid addition, which were then equilibrated over 3 days to a water activity of 0.45. Oat flour samples (100 g) were sent to and subsequently processed by each of the four laboratories using their own isothermal inactivation procedures (80°C). Samples then were serially diluted and plated on trypticase soy agar supplemented with yeast extract. All resultant data were compiled and analyzed collectively. Average populations of S. Agona in the three oat flour samples before thermal treatment were 7.90±0.20, 7.75±0.25, and 7.75±0.29 log CFU/g. Resultant D80°C-values were 8.15, 10.70, 15.27, and 18.58 min across the four laboratories. Using a one-way ANCOVA, differences in inactivation rates within laboratories were not significantly different (P > 0.05); however, differences in inactivation rates between laboratories were significant (P < 0.05). Despite the use of identical inoculated matrices, and similar thermal treatment methods, thermal inactivation rates varied significantly among the four laboratories. Lab- or method-dependent artifacts contributing to such differences affect the ability to utilize results from separate studies, which also suggests that model validation is critical prior to utilizing single-study results for pasteurization validations or regulatory guidance. While challenge studies between laboratories help develop a baseline understanding of variability and uncertainty between laboratories, there are no guidelines to gauge the robustness of the challenge study. A theoretical sensitivity analysis of isothermal inactivation process controls and data analysis methods may yield a range of achievable variability. Process controls for isothermal experiments (temperature and water activity accuracy), biological replication error, and data standardization practices were incorporated into Monte-Carlo simulations (using Matlab software) to determine potential effects on estimated model parameters and errors. Preliminary results suggest that data standardization practices and increasing error in process controls contribute to larger ranges of expected parameter values than what was achieved with no process error. Additionally, results suggest that the use of any data standardization, which is essential for model fitting, increases the likelihood of type I error (falsely distinguishing two similar parameters as different). For the surrogate study, six standardized test materials have been selected to represent a broad domain of critical product characteristics: almonds, peanut butter, wheat flour, nonfat dry milk, ground black pepper, and dates. The materials have been centrally acquired and are being distributed to each of the project laboratories. Additionally, a standardized, five-strain Salmonella cocktail has been selected (representing strains linked to prior outbreaks and recalls associated with low-moisture products) and is being distributed to each laboratory (via our FDA collaborators), including isolates of Salmonella Enteritidis PT30, Tennessee, Agona, Montevideo, and Mbandaka. Initial tests have already been completed with the non-pathogenic surrogate (Enterococcus faecium NRRL B-2354) in wheat flour, peanut butter, and dates, indicating general acceptability of the surrogate, but confirming product-specific relationships between the surrogate and Salmonella response to product and process conditions. OBJECTIVE 4: Several members of the project team (including our FDA collaborator) presented our first mini-workshop to an industry audience (approximately 35 attendees) at the 2015 Process Expo in Chicago, IL, as part of Process Expo U. The mini-workshop was entitled: "Considerations for Validation of Thermal Processes Used in the Manufacture of Low Moisture Foods." The scope encompassed: (1) regulatory expectations for process validations and FSMA compliance, (2) application of microbial inactivation models for low-moisture process validations, and (3) a specific case study on validation of a radio-frequency pasteurization process. The workshop was recorded, so it can be made available for future distribution and training activities. OBJECTIVE 5: Preliminary content and 34 targeted learning outcomes have been developed (as part of a graduate student project) for seven online graduate education modules, in the following areas (with specific focus on low-moisture food systems): (1) overview of process validation, (2) processing technologies, (3) microbiological concepts, (4) heat and mass transfer principles, (5) microbial modeling principles, (6) scale-up and process control and (7) documentation and reporting.

Publications

  • Type: Other Status: Published Year Published: 2015 Citation: Anderson N, Grasso E, Marks B, Subbiah J. 2015. Considerations for Validation of Thermal Processes Used in the Manufacture of Low Moisture Foods. Presented as Mini-Workshop. Process Expo University. September 14, 2015. Chicago, IL.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Hildebrandt, I.M., Anderson, N.M., Limcharoenchat, P., Hall, N., Xu, J., Zhu, M., Marks, B.P., Tang, J., Grasso-Kelley, E.M. 2016. Quantifying reproducibility of Salmonella thermal resistance through a multiple inter-laboratory comparison. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Pickens, S., Burbick, S., Jin, Y., Hildebrandt, I., Grasso-Kelley, E.M., Keller, S.E., Anderson, N.M. 2016. Thermal resistance of Salmonella enterica in a high protein matrix at varying water activities. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Luo, Y., Grasso-Kelley, E.M., Anderson, N.M. 2016. Impact of macronutrients on the temperature dependence of water activity in a multicomponent food system. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Wang, W., Anderson, N.M., Hildebrandt, I., Grasso-Kelley, E.M. 2016. Inactivation of Salmonella during baking a high-protein model food. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Zhang, J., Hildebrandt, I.M., Grasso-Kelley, E.M., Keller, S.E., Anderson, N.M. 2016. Performance comparison of aluminum test cells and glass vials for determining heat resistance in low-moisture foods. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Garces-Vega, F., Marks, B.P. 2016. Evaluation of water content as a convenient metric in thermal inactivation modeling for low-moisture foods. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Limcharoenchat, P., James, M., Hall, N., Marks, B. 2016. Moisture equilibration and product fabrication methods affect measured thermal resistance of Salmonella Enteritidis PT30 on/in whole almonds, almond meal, and almond butter. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Liu, S., Zhong, Q., Smith, D.F., Villa-Rojas, R. Tang, J. Zhu, M.J., Marks, B. P. 2015. Validation of Enterococcus faecium NRRL B2354 as a surrogate for Salmonella in thermal treatment of wheat flour at different water activities. Annual meeting of International Association for Food Protection. Portland, Oregon, July 25-28, 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Syamaladevi, R. M., Tadapaneni, R. K., Garces-Vega, F. J., Tang, J., Marks, B. P., Carter, B., Sablani, S. S. 2015. Water Activity Variation at Elevated Temperatures and Thermal Resistance of Salmonella in Selected Low-Moisture Foods. International Association for Food Protection, Annual Meeting. Portland, Oregon, July 25-28, 2015.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Jin, Y., Burbick, S., Pickens, S., Hildebrandt, I., Keller, S.E., Anderson, N.M., Grasso-Kelley, E.M. 2016. Thermal inactivation of Salmonella Agona in a high-fat matrix as influenced by water activity. Institute of Food Technologists, Annual Meeting. Chicago, Illinois, July 16-19, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Liu, S., Syamaladevi, R., Zhu, M.J., Tang, J. 2016. Isothermal inactivation of Salmonella and Enterococcus faecium in dates impacted by water activity variation at elevated temperature. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Xu, J., Syamaladevi, R., Liu, S., Tadapaneni, R.K., Tang, J., Zhu, M.J., Devendra, S. 2016. Evaluation of thermal resistance of Enterococcus faecium NRRL B-2354 in wheat flour and peanut butter using both TAC and TDT cells. International Association for Food Protection, Annual Meeting. St. Louis, Missouri, July 31-August 3, 2016.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Syamaladevi, R. M., Tang, J., Villa-Rojas, R., Sablani, S. S., Carter, B., Campbell, G. (2016). Influence of Water Activity on Thermal Resistance of Microorganisms in Low-Moisture Foods: A Review. Comprehensive Reviews in Food Science and Food Safety, 15(2), 353-370.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Syamaladevi, R. M., Tadapaneni, R. K., Xu, J., Villa-Rojas, R., Tang, J., Carter, B., Sablani, S. S., Marks, B. 2016. Relationship between water activity variation at elevated temperatures and thermal resistance of Salmonella in selected low-moisture foods, Food Research International, 81, 163-170.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Tadapaneni, R.K., Syamaladevi, R.M., Tang, T. Villa-Rojas, R. 2016. Study of thermal resistance of Salmonella in low moisture foods inside a closed system maintained with stable water activity at the elevated temperatures. Annual Meeting of American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Liu, S., Zhu, Z., Tang, J., Zhu, M. J. 2016. Validation of radio frequency-assisted pasteurization in low-moisture foods using Enterococcus faecium. Annual Meeting of American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Xu, J., Liu, S., Tang, J., Zhu, M.J., Devendra, S.H. 2016. Evaluation of thermal resistance of fresh and freeze-dried Enterococcus faecium NRRL B-2354 in wheat flour using both TAC and TDT cells. Annual Meeting of American Society of Agricultural and Biological Engineers, Orlando, Florida, USA, July 17-20, 2016