IAFP Annual Meeting 2017
Tampa, Florida, USA
July 9, 2017 – July 12, 2017
ILSI North America is sponsoring 4 scientific sessions and 2 posters at the 2017 International Association for Food Protection Annual Meeting. Explore all the presentations below.
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 Bacteriophage to Control Foodborne Pathogens in the Food Processing Environment and in Ready-to Eat Foods
Sam Alcaine, Cornell University
Supported by the ILSI North America Technical Committee on Food Microbiology
Fate of Listeria monocytogenes in Cocoa Powder during Isothermal Inactivation
Presentation on Wednesday, July 12, 2017
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.