Simulating Powdered Product Sampling to Improve Food Safety Sampling Plans

Drawing accurate conclusions about whether an ingredient or finished product is safe based on the results of a test is important to the evaluation and management of food safety risk. With the expected prevalence of contamination in today’s food system at less than 1%, extremely large samples sizes are required to reliably detect contamination, and the potential for false negatives during routine sampling is high. It is therefore critical that samples are representative of the ingredient or product being evaluated, and that sampling plans maximize the probability of finding a target hazard -- particularly as contamination patterns are often heterogeneous rather than uniform.  This project will leverage a recently-developed bulk product simulation model to create a publicly available model used to detect low-prevalence, low-level contamination in powdered products and ingredients, such as powdered milk and cocoa powder.

Institution: University of Illinois at Urbana-Champaign
Principal Investigator: Matthew Stasiewicz, PhD
Year Awarded: 2021

Access the interactive web app designed to run sampling simulation

  • An extended tutorial/user video to utilize the app can be found here

View this project on the Center for Open Science’s Open Science Framework.

Learn more about the IAFNS Food Microbiology Committee.


IAFNS at IAFP 2023

Join IAFNS at the IAFP 2023 Annual Meeting July 16-19, 2023 in Toronto, Ontario, Canada:

IAFP 2021 Annual Meeting

Each year, the International Association for Food Protection hosts an Annual Meeting, providing attendees with information on current and emerging food safety issues, the latest science, innovative solutions to new and recurring problems, and the opportunity to network with thousands of food safety professionals from around the globe.

This year, IAFNS Food and Chemical Safety Committee and Food Microbiology Committee are supporting the four sessions at the IAFP Annual Meeting.

Learn more about the IAFP Annual Meeting.

IAFP 2020 Annual Meeting

IAFP’s European Symposium on Food Safety

IAFP 2019 Annual Meeting

Each year, the International Association for Food Protection hosts an Annual Meeting, providing attendees with information on current and emerging food safety issues, the latest science, innovative solutions to new and recurring problems, and the opportunity to network with thousands of food safety professionals from around the globe.

IAFNS is supporting three sessions, a roundtable event and three posters at the 2019 IAFP Annual Meeting.

Scientific Sessions:

Roundtable Event:

Poster Presentations:

A Novel Simulation Approach to Improving the Effectiveness of Sampling for Bulk Food Products - Video
Eric Cheng, University of Illinois | P1-124 | Monday, July 22, 8:30am - 6:15pm

Global Gene Expression Analysis of Salmonella Contaminating Low-Moisture Foods - Video
Victor Oladimeji Jayeola, North Carolina State University | P1-201 | Monday, July 22, 8:30am - 6:15pm

Prevalence and Characteristics of Selected Foodborne Bacterial Pathogens in Post-Hurricane Florence Floodwaters - Video
Jeff Niedermeyer, North Carolina State University | P3-161 | Wednesday, July 24, 8:30am - 3:30pm

These projects are supported by the IAFNS Food Microbiology Committee.

Learn more about the IAFP Annual Meeting here.

19th IUFoST World Food Science and Technology Congress 2018

IAFP 2018 Annual Meeting

IAFP 2017 Annual Meeting


IAFNS is sponsoring 4 scientific sessions and 2 posters at the 2017 International Association for Food Protection Annual Meeting. Explore all the presentations below. 

Scientific Sessions

Controlling foodborne pathogens

Battling Bad Bugs: Biological Approaches to Control Pathogens
Monday, July 10, 2017 from 3:30- 5:00 PM

Session Conveners: Isabel Walls, USDA NIFA, and Kendra Nightingale, Texas Tech University

The food industry often relies on physical and chemical interventions to control foodborne pathogens. This session is intended to discuss biological approaches to control foodborne pathogens throughout the food continuum. Topics to be covered include the use of (i) biocontrol of Listeria monocytogenes and Salmonella enterica Serovar Poona on fresh-cut apples with naturally occurring bacterial and yeast antagonists, (ii) probiotics to reduce the load of foodborne pathogens that enter the human food chain and pathogen populations on food and in food processing environments and (iii) bacteriophage to combat bacterial foodborne pathogens. This session will also include discussions on consumer perception and acceptance of these biological approaches to control foodborne pathogens.

Biocontrol of the Food-Borne Pathogens Listeria monocytogenes and Salmonella enterica Serovar Poona on Fresh-Cut Apples with Naturally Occurring Bacterial and Yeast Antagonists
Wojciech Janisiewicz, USDA ARS

Application of Probiotics to Control Foodborne Pathogens from Farm to Fork
Mindy Brashears, Texas Tech University

Application of Bacteriophage to Control Foodborne Pathogens in the Food Processing Environment and in Ready-to Eat Foods
Sam Alcaine, Cornell University

Supported by the IAFNS Technical Committee on Food Microbiology

Managing Risk
Debate: Food Safety Perspectives
Chemical & Microbial Risk Assessment

Poster Presentations

Listeria monocytogenes

Fate of Listeria monocytogenes in Cocoa Powder during Isothermal Inactivation
Presentation on Wednesday, July 12, 2017

Download Poster

Authors: Hsieh-Chin Tsai, Washington State University, Marizela Silva, Washington State University, Juming Tang, Washington State University, Meijun Zhu, Washington State University

Introduction: Listeria monocytogenes can survive in dry condition for a long period of time. Despite an increasing number of studies addressing Salmonella inactivation in low-moisture foods, there is a general lack of knowledge related to L. monocytogenes inactivation in low moisture foods during thermal processing and to the factors impacting their survival in low moisture food. Cocoa powder is an essential ingredient and widely incorporated in different desserts and drinks and thus a possible source of L. monocytogenes contamination.

Purpose: To evaluate the thermal resistance of L. monocytogenes in cocoa powder and further investigate the impact of water activity (aw) on its survival in cocoa powder.

Methods: Natural unsweetened cocoa powder (Hershey’s) was inoculated with three-strain L. monocytogenes cocktail (~9.0 log CFU/g), equilibrated to water activity (aw, 25°C) to 0.3 or 0.45, then subjected to isothermal treatments using aluminum TDT test cell containing 0.4 g of inoculated and equilibrated sample. The survivors were enumerated on TSAYE plates.

Results: Inactivation data resulted from different temperatures at both aw showed log-linear trend which was used to obtained thermal inactivation parameters. Thermal resistance of L. monocytogenes at 0.3 aw was significantly higher than that at 0.45 aw across all three temperatures. Listeria monocytogenes at 0.3 aw and 0.45 aw had D70°C of 7.44±1.17 and 4.77±0.28 min, D75°C of 3.62±0.03 and 2.84±0.09 min, and D80°C of 1.35±0.04 and 1.06±0.05 min, respectively, z-value at 0.3 aw and 0.45 aw was 13.48 and 15.31°C, respectively.

Significance: Listeria monocytogenes demonstrated much higher thermal resistance in cocoa powder compared to the high moisture foods, which is impacted by aw. Data provide valuable information for industry to validate thermal processing for control of L. monocytogenes in low moisture foods.


ASTA Annual Meeting

Nancy Bontempo, PhD, Mondelez International
Delia Murphy, IAFNS

This presentation will provide an overview of the results of two IAFNS sponsored research projects: “Correlation of surrogate bacteria and Salmonellae for validation of spice/herb pathogen reduction processes” and “Protocol and surrogate validation for the inactivation of Salmonella on whole black peppercorns and cumin seeds.”

The projects used four spices, oregano, onion powder, whole black peppercorns, and whole cumin seeds, and focused on evaluating the usefulness of surrogate bacteria for validation of irradiation as a decontamination processes, and developing validated protocols for inactivation of Salmonella using ethylene oxide fumigation and dry steam (vacuum-assisted) treatment. The American Spice Trade Association provided an unrestricted grant to help fund these research projects.

This work is supported by the IAFNS Food Microbiology Committee.

IAFP 2016 Annual Meeting


Inoculation Preparation Affects Survival of Salmonella enterica on Whole Black Peppercorns and Cumin Seeds Stored at Low Water Activity