Regulatory View
of
Microwave Pasteurization
Gregory J. Fleischman, Ph.D.
Institute for Food Safety and Health
U.S. Food and Drug Administration
gregory.fleischman@fda.hhs.gov
June 10, 2011
45th International Microwave Power Institute Symposium
FDA and USDA
FDA regulates…
foods except meat and poultry products
food products containing less than 2 percent cooked meat/poultry
and containing less than 3 percent raw meat.
the manufacturing of meat sauces and most soups
game meat (e.g., venison, ostrich and snake)
eggs after inspection
USDA regulates
most meat and poultry
eggs at the production level
Pasteurization
Defined in Section 403 of the Federal Food, Drug,
and Cosmetic (FD&C) Act [21 U.S.C. 343] as
amended by the 2002 Farm Bill
Interpretation:
“Any process, treatment, or combination thereof, that
is applied to food to reduce the most resistant
microorganism(s) of public health significance to a
level that is not likely to present a public health risk
under normal conditions of distribution and storage.”
National Advisory Committee on Microbiological Criteria for
Foods. 2006. Journal of Food Protection, Vol. 69, No. 5, 2006,
Pages 1190–1216
Milk
Examples
governed by the Pasteurized Milk Ordinance (PMO)
the PMO is prescriptive, stipulates time/temperature
requirements
target organism: originally Mycobacterium tuberculosis, now
Coxiella burnetii
Juice
governed by the Juice HACCP Regulation (21 CFR 120.24(a))
each juice requires its own HACCP plan
target organism: variable, and may be other contaminants as
well, e.g., chemical contaminants
Eggs
governed by the 2009 Egg Safety Action Plan (21 CFR Parts
16 and 118)
Producers are exempt from 6 of 7 provisions of this plan by
pasteurizing eggs
Target organism: Salmonella Enteritidis
Microwave
Pasteurization
21 CFR 179.30
Radio frequency radiation, including microwave frequencies, may be
safely used for heating food under the following conditions:
The radiation source consists of electronic equipment producing
radio waves with specific frequencies for this purpose
authorized by the Federal Communications Commission.
The radiation is used or intended for use in the production of
heat in food wherever heat is necessary and effective in the
treatment or processing of food.
Achieving Pasteurization
Talk to FDA concerning process goal
Identify target organism(s)
Determine level of inactivation required
• determine initial potential bacterial load
• establish variations in this load
Determine the effect of the food matrix on organism survivability
Insure that process does not create a hazard as a consequence to
pasteurization
Validate the process
Verify the process
Submit findings to FDA
Achieving Pasteurization
Talk to FDA concerning process goal
Identify target organism(s)
Determine level of inactivation required
• determine initial potential bacterial load
• establish variations in this load
Determine the effect of the food matrix on organism survivability
Insure that process does not create a hazard as a consequence to
pasteurization
Validate the process
Verify the process
Submit findings to FDA
Validation and Verification
of Pasteurization Processes
Validation = does your process work?
demonstrate that pasteurization is achieved
throughout food
establish critical factors and their acceptable range
establish means to monitor critical factors
insure that validation procedure doesn’t change
process
Verification = does it keep working?
monitor critical factors
Potential Critical Factors
in Microwave Pasteurization
Food factors
• composition
• physical characteristics (shape, size, volume)
• physical state (liquid, solid, ice)
• changing product parameters (e.g., specific heat)
Process factors
• power level and cycling
• process time
• equilibration time
Equipment factors -- magnetron frequency and age
Packaging -- effect on process delivery
The Microwave Validation
Challenge
Continuous processing (liquids) is straightforward
adequate mixing assures uniform temperatures
downstream direct measurement of temperature levels
Discrete processing (individual packages) is not straightforward
non-uniform temperatures
only indirect assessment of temperature levels possible
example: microwave pasteurization of shell eggs
Shell Egg Pasteurization
Uniformly inoculated egg
Clear vs. Cloudy albumen
FDA Review
FDA doesn’t…
• prescribe validation protocol
• approve processes
FDA does…
advise producers on what is expected in a validation
protocol
review validation protocol
Issues a letter of no objection if validation protocol is
deemed sufficient to support pasteurization claim