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Keeping Listeria at Bay: The battle that ready-to-eat processors can’t afford to lose. Host: Bill Kinross, Publisher, Meatingplace Moderator: Lisa Keefe, Editor, Meatinglace. Presenter. Harshavardhan Thippareddi,
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Keeping Listeria at Bay:The battle that ready-to-eat processors can’t afford to lose Host: Bill Kinross, Publisher, Meatingplace Moderator: Lisa Keefe, Editor, Meatinglace
Presenter Harshavardhan Thippareddi, Associate Professor of Food Science, Department of Food Science and Technology, University of Nebraska, Lincoln
Listeria Control:Old Problem, New Solutions Harshavardhan Thippareddi, Ph. D. www.meatingplace.com Sept 9, 2009 Prepared by: Martin Wiedmann, Ph. D., Cornell University, Ithaca, NY
Well Known “Facts” Human listeriosis can occur as an epidemic or as sporadic cases L. monocytogenes common in certain/many environments L. monocytogenes grows at refrigeration temperatures Infectious dose is high Growth in foods is usually needed to reach levels likely to cause human disease Martin Wiedman, Cornell University
Human exposure is common Majority (ca. 99%) of human listeriosis cases are foodborne Potentially long incubation period (7-60 days) Human listeriosis affects predominantly elderly and immunocompromised people, pregnant women and newborns Well Known “Facts” Martin Wiedman, Cornell University
The FDA-CSFAN, USDA-FSIS, & CDC Risk Assessment – Highlights Most human listeriosis cases in US appear to be caused be contaminated deli meats RTE deli meats – 1,598 cases Pasteurized milk – 90 cases High fat and other dairy products – 56 cases Not-reheated frankfurters – 31 cases Cooked ready-to-eat crustaceans – 2.8 cases Smoked seafoods 1.3 cases Fruits and vegetables – 1.1 cases
Prevalence Of Listeria Monocytogenes On RTE Meat And Poultry Products* Percent Positives *FSIS results of ready-to-eat products analyzed for Listeria monocytogenes
Human Listeriosis - Trends http://www.cdc.gov/FoodNet/factsandfigures/trends.html
Listeria Monocytogenes Prevalence(%) On RTE Meat And Poultry, 2008 http://www.fsis.usda.gov/Science/Table22_Micro_Testing_RTE_2008/index.asp
Challenges Towards Continuous Reduction Of Human Listeriosis LM is common throughout the food chain A single magic bullet will not work Focusing on one product (RTE deli meats) at one point (processing) does not seem to work
USDA-FSIS Final Rule –RTE Processing Establishments Establishments producing post-lethality exposed RTE product must comply with requirements included in one of the following alternatives (§430.4) Alternative 1:Use post-lethality treatment AND an antimicrobial agent or process Alternative 2: Use post-lethality treatment OR an antimicrobial agent or process Alternative 3: Use sanitation measures ONLY
Physical Post-lethality Treatments Heating Steam Submersion in hot water Radiant oven heating High Pressure Processing
Thermal (Surface) Pasteurization Systems for RTE Meat Products Meat product type and composition Whole muscle vs. restructured product - product surface characteristics Thermal properties Product packaging Packaged vs. non-packaged Film thickness and material Product orientation & package design Single vs. double layer – hot dogs Sliced product – deli type products
Product Orientation Effects .75” Single-Layer Separated Franks Single-Layer Franks 1.5” Double-Layer Franks Courtesy: Alkar
Product Orientation Effects Turkey breast Roast beef Ham Courtesy: Alkar
Thermal (Surface) Pasteurization Systems for RTE Meat Products Hot water-based systems Steam-based systems Non-condensing steam Condensing saturated steam Flash steam system
Destruction Of L. Monocytogenes Using Hot Water System Muriana et al., 2002
High Hydrostatic Pressure Systems Non-thermal intervention technology Minimal quality changes Can be combined with other treatments such as heat Pressures in the range of 250 MPa (36,260 PSI) to 600 MPa (87,023 PSI) 100 MPa=14,504 PSI
High Hydrostatic Pressure Treatment – Factors Controlling Application Product type and composition Processing time and temperature Types of microorganisms to be inactivated
Antimicrobial Agents – Lethality Treatments Acidic calcium sulfate Acidified sodium chlorite Peracetic acid Lauric arginate ε- polylysine
Antimicrobial Agents – Lethality Treatments Liquid smoke fractions Listeria phages Octanoic acid Ozone (ozonated water)
Acidic Calcium Sulfate Nunez et al., 2004
Acidic Calcium Sulfate Nunez et al., 2004
Acidified Sodium Chlorite Luchansky et al. 2006
Model System – Ε- Polylysine Geornaras et al., 2005
Smoke Derivatives – L. Monocytogenes Control Gedela et al. 2007
Organic Acids Salts Approved for meat product use Sodium or Potassium salts of lactic acid Sodium acetate or diacetate Sodium citrate buffered with citric acid to pH 5.6 Live bacteria – Canbiocin Levulinate (not commercialized yet)
Acknowledgments This Project was funded through a grant from the National Integrated Food Safety Initiative (Special emphasis grant No. 2005-51110-03278) of the Cooperative State Research, Education and Extension Service, U. S. Dept. of Agriculture
Presenter John N. Butts, Vice President of Research, Land O’ Frost
Data Analysis, Investigation and Corrective Action “Follow the data trail to the source but always be alert and aware to the organism’s ubiquitous presence and pervasive nature.” John Butts Land O’ Frost Meatingplace Webinar Sept 2009
Commitment Model Resistant – don’t believe it has value Accepting – why not “Buy-in” – we will do it Engagement – involved in solution Commitment – hold self and others accountable for achieving results
Sources of Ls in High-Risk RTE Area Transferred from Zone 4 area outside of the High-Risk RTE area Homeless, but looking for a harborage location Typically found with a transfer point monitoring positive Growth niches within High-Risk RTE area This means they are established, and have found a protective home in equipment or facility. They may exist in a transient home such as rework pans, trash containers or other difficult to clean mobile container / environment.
Transfer Points vs Niches Many positive sites found during monitoring are not growth niches. They are transfer points (i.e., a product handler’s gloved hands, floor sample in high traffic pathway). Transfer points are not growth niches because the organism is eliminated during the cleaning and sanitizing process.
GrowthNiches Locations harboring the organism after the routine sanitation process for that area has been completed. Examples • Hollow roller on conveyor transporting food product • Hollow rollers not disassembled cleaned and sanitized or heat treated in a manner to eliminate any contaminating organisms can become growth niches.
Growth Niches Hollow roller with solid stainless steel shaft in center (almost press fit). When center shaft removed organic matter is evident.
GrowthNiches Must either be designed out of the system or managed as a part of the process. Design Examples Equipment is redesigned to eliminate or seal hollow areas Hollow areas of equipment (e.g., frames, rollers) must be eliminated where possible or permanently sealed (caulking not acceptable). Bolts, studs, mounting plates, brackets, junction boxes, name plates, end caps, sleeves and other such items must be continuously welded to the surface of the equipment and not attached via drilled and tapped holes. AMI Equipment Design Task Force
Growth Niches Minimize with process control techniques The potential to support growth still exists within the machine, part or area Whenever this becomes the chosen path remember to implement methods that will hold the gains with turnover in both hourly and management ranks.