1. FDA/CFSAN: Food Irradiation Presented by: Dr. Lane Highbarger
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FDA/CFSAN: Food Irradiation
Presented by: Dr. Lane Highbarger
Tuesday, May 11, 2010

2. Food Irradiation Lane A. Highbarger, Ph.D.
Division of Biotechnology and GRAS Notice Review
Office of Food Additive Safety
Center for Food Safety and Applied Nutrition
May 11, 2010

3. Poll Question Have you ever knowingly purchased an irradiated food?
Yes No
How would I know?
Labeling of food is only for foods that have been irradiated.
It is highly unlikely that you have purchased pre-made food that does NOT contain irradiated spices. l

4. Energy

5. Radiation Spectrum

6. Sources of Radiation Cobalt 60 - 1.33 MeV Cesium 137 - 662 keV
Electron accelerators operated at
10 MeV or less
X-ray generators operated at
7.5 MeV or less

7. Dose – What it Means Irradiation doses are measured in gray (Gy)
Gy is measured in joule/kg absorbed energy
1 Gy = = 1 m2  s-2
For X-rays and gamma rays == Sievert
Energy sources are constant
Applied dose = energy source ✕ time exposed
Absorbed dose depends on other factors J Kg

8. Food Irradiation Facilities
Gamma
Electron beam

9. Let’s Pause for Questions?

10. Food Irradiation Overview

11. A Brief History of Food Irradiation
1905 Begins the era of food irradiation.
1958 Congress defines a source of radiation as a food additive.
1980 Foods irradiated up to 10 kGy considered to be safe and wholesome.
1997 Foods irradiated at any dose should be considered as safe and as wholesome as foods treated by any other conventional process.
2001 Irradiation is used to eliminate possible traces of Anthrax.
FDA approves the use of irradiation in a variety of foods.
1905 Scientists receive patents for a food preservation process that uses ionizing radiation to kill bacteria in food.
1921 A U.S. Patent is granted for a process to kill Trichinella spiralis in meat using x-rays.
Animal feeding studies are performed to assess the wholesomeness of irradiated food.
1943 Scientists at the Massachusetts Institute of Technology show that x-rays can be used to preserve ground beef.
1950’s Beginning of era of food irradiation in the U.S. and Europe, with studies involving wholesomeness and application of the technology dominating the research.
1953 Formation of the U.S. National Food Irradiation Program, a project of the U.S. Army and the Atomic Energy Committee.
The Army Medical Department oversees a program to study the safety and wholesomeness of 21 irradiated foods. The Army Surgeon General concludes that foods irradiated up to a specific dose pose no significant health risks to humans.
1958 Congress classifies irradiation as an additive; therefore, a food additive petition detailing each application is required before irradiation can be used.
1976 The Joint Expert Committee on the Wholesomeness of Foods, formed by the World Health Organization, International Atomic Energy Agency, and Food and Agriculture Organization of the United Nations, convenes with scientists and other experts to recommend that food irradiation should be classified as a process, not an additive.
1980 The Joint Expert Committee designates that foods irradiated up to 10 kGy be considered safe and wholesome.
1997 The Joint Expert Committee designates that foods irradiated at any dose should be considered as safe and as wholesome as foods treated by any other conventional process.
2001 Irradiation is used by the U.S. Postal Service to eliminate possible traces of Anthrax. Consumers begin to understand the technology and acceptance grows.

12. Why Irradiate? Low Dose (<1 kGy) Medium Dose (1-10 kGy)
Control insects
Inhibit maturation
Inhibit sprouting
Medium Dose (1-10 kGy)
Extend shelf life
Reduce microorganism level
High Dose (> 30 kGy)
Sterilize - analogous to canning
Decontaminate certain food additives, e.g., spices

13. Foods Permitted to Be Irradiated Under FDA’s Regulations
All foods Arthropod Control 1 kGy max
Dry Enzyme Preps. Microbial Control kGy max
Fresh Foods Maturation Inhibition 1 kGy max
Spices/Seasonings Microbial Control kGy max
Poultry Microbial Control 3 kGy max
Seeds for sprouting Microbial Control 8 kGy max
Shell eggs Microbial Control 3 kGy max
Meat and meat byproducts Microbial Control kGy/7 kGy
Molluscan shellfish Microbial Control kGy max
Fresh lettuce and spinach Microbial Control 4 kGy max
NASA Sterilization kGy min

14. Other Irradiated Substances
Medical equipment Microbial Control
Laboratory animal Microbial Control
diets kGy max
Poultry feed Salmonella spp.
25 kGy max
Pet foods, treats and Salmonella spp.
chews kGy max

15. Best return on irradiation
Which foods do you think would benefit most from being irradiated? Either from a food safety point of view or a commercial point of view. A) Ground beef B) Lettuce C) Shell eggs D) Fruits E) NASA beefsteak

16. Let’s Pause for Questions?

17. Irradiation Action

18. Method of Action E-beam – shallow penetration
Converted to x-ray for more penetration
Gamma – ‘deeper’ penetration
All act via similar mechanisms

19. Susceptibility
Mammals > Insects > Single Celled Organisms > Viruses; (Prions Likely Resistant)
D10 – The radiation dose needed to inactivate 90% of the microbial load in the food medium
Jejuni – common poultry

20. Bacterial Susceptibility
All bacteria have different susceptibilities to radiation (values in kGy)
Salmonella spp. –
Listeria monocytogenes –
E. coli O157:H7 –
A % reduction = 5 x D10 value
Jejuni – common poultry

21. Perceptions
Which number sounds better as a descriptor for the reduction of a bacterial population? And which one is the greatest kill?
A) 5000 times
B) 99.99%
C) Reduced by 10-5
D) A 4 D10 reduction
E) I have a headache now
Jejuni – common poultry
Want to do this poll 2x

22. Let’s Pause for Questions?

23. Safety Considerations

24. Safety Considerations
Radiological Safety
Chemical Change and Potential Toxicity
Nutritional Adequacy
Potential Microbiological Hazard

25. Chemical Change Energy stimulates chemistry
Increases when liquid is present
Initiates reaction with air
Generally little – but not necessarily negligible change
Can be controlled by controlling conditions

26. Heated Lipid (180 ºC/1Hr) vs Irrad (120 kGy)

27. Nutrition Issues Vitamins can be labile to heat and irradiation
Thiamine and ascorbic acid (vitamin C) are the most radiation-sensitive of the water-soluble vitamins,
followed by other B-complex vitamins in order of decreasing sensitivity: pyridoxine, riboflavin, folic acid, cobalamin, and nicotinic acid (Ref. 2 Diehl).
As for fat-soluble vitamins, vitamin E and vitamin A are the most sensitive;
vitamins D and K are quite insensitive.

28. Microbiological Radiation sensitivity varies with species
Sensitivity varies with environment
Temperature; water Activity; pH; Salt; etc
Same as heating

29. Poll Question
Has an explanation about food irradiation made you feel more or less comfortable about purchasing irradiated foods?
Do you want more information?
More
Yes
Les No

30. Let’s Pause for Questions?

31. Foods Currently Under Review
Crustaceans
Multiple-ingredient products
Non-refrigerated meat food products
Poultry
Dietary supplements

32. Labeling Criteria
The FDA requires that irradiated foods bear the radura label and state on the label “Treated with radiation” or “Treated by irradiation”
There is no statutory requirement specific to irradiation

33. Poll Quesiton
Would you prefer to have food labeled if it were irradiated? √ Yes X No

34. Controversy and Queries
Objections
Consumer
Public Citizen / Center for Food Safety
Formal Correspondence

35. Let’s Pause for Questions?

36. Other non-Thermal Mitigation Technologies

37. High Pressure Processing
80k – 130k lb/in2
Effective at elimination of microbial contamination
Spores are resistant
Expensive

38. Pulsed Field Short bursts of electricity used for microbial control.
Liquids, e.g., juice, milk, liquid eggs.
Low cost.

39. UV Radiation Effective at microbial decontamination in liquids.
Approved for use in surface decontamination.
Approved for use in juices.

40. Web Based Information Resources Food Safety and Irradiation
Food Irradiation Processors Alliance –
Kansas State University –
USDA Fact sheet –
FSIS on labeling –
Food Safety dot gov –
Printable information: Irradiated Lettuce and Spinach –
Recent News: E. coli O145 in romaine lettuce –
WSJ Blog on E. Coli –

41. Thank you to the sponsor of tonight's Web Seminar:

44. National Science Teachers Association
Dr. Francis Q. Eberle, Executive Director
Zipporah Miller, Associate Executive Director Conferences and Programs
Al Byers, Assistant Executive Director e-Learning
NSTA Web Seminars
Paul Tingler, Director
Jeff Layman, Technical Coordinator
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