1. Food Irradiation The present & the future of food processing The Law and the Science of Food Irradiation

2. Food Safety New Paradigm for Y2K Emerging Pathogens Foodborne Illness Outbreaks Food Safety Regulation

3. Food Irradiation Exposure of foods to ionizing radiation in form of gamma radiation, X-rays and electron beams to destroy pathogenic microorganisms In use for over 50 years in European Union US consumers perceptions of effects of radiation prevented widespread acceptance of food irradiation Limited use allowed since 1963 on specific food products for specific purposes.

4. Ionizing Radiation Causes disruption of internal metabolism of cells by destruction of chemical bonds DNA cleavage results in loss of cells ability to reproduce “Free radicals” formed upon contact with water containing foods Free radicals react with cellular DNA causing radiation damage DNA considered “radiation sensitive” portion of cells

5. Ionizing Radiation Exists in form of waves Shorter wavelength = greater energy Light, radio, microwave, television = long wavelength, low energy cannot alter structure of an atom Shorter wavelengths have enough energy to “knock off” an electron to form a “free radical” but not high enough to “split” an atom and cause target to become “radioactive” Interaction between free radicals and DNA responsible for “killing effect” of IR

6. X- Rays Produced during high energy collisions of gamma rays and heavy elements (i.e. Tungsten) Little practical application because of low conversion efficiency of gamma to X-rays

7. Electron Beams Produced by linear accelerators Coherent, directional beam of high energy electrons Low dose Portable (no reactor required) Not inherently radioactive Requires less shielding than gamma radiation Flip of the switch technology Lack penetration depth of gamma Advantage is shorter exposure time

8. Gamma Radiation Most widely used type of ionizing radiation All penetrating, emitted in all directions continuously Produced at MURR by exposure of natural Cobalt-59 to neutrons in a reactor where reaction between the two species produces Cobalt-60 Cobalt-60 specifically manufactured, for radiotherapy, medical device sterilization and food irradiation, not a waste product of nuclear reactors

9. What is Food Irradiation Food irradiation is a process in which food products are exposed to a controlled amount of radiant energy to increase the safety of the food and to extend shelf life of the food Like pasteurization of milk and pressure cooking of canned foods, treating food with ionizing radiation can kill bacteria and parasites that would otherwise cause foodborne disease.

10. Irradiation….also known as: Ionizing radiationIonizing radiation Surface pasteurizationSurface pasteurization Electronic pasteurizationElectronic pasteurization E-beam sterilization/pasteurizationE-beam sterilization/pasteurization

11. Ionizing radiation When radiation strikes other material, it transfers energy. This can cause heating, as with microwave cooking, or if there is enough energy, it can knock electrons out of the material bombarded, breaking the molecular structure-thus leaving ions (free radicals) hence the name ionizing radiation.

12. Electromagnetic Spectrum Low Frequency Long Wavelengths High Frequency Short Wavelengths

13. Sources of Ionizing irradiation Gamma sources of irradiationGamma sources of irradiation X-ray machinesX-ray machines Electron acceleratorsElectron accelerators

14. Gamma (  ) rays Energy comes from decay of radioactive isotopesEnergy comes from decay of radioactive isotopes –Cobalt-60 (half life of 5.3 years) Produced by neutron bombardmentProduced by neutron bombardment –Cesium-137 (half life of 30 years) By-product of spent nuclear fuelBy-product of spent nuclear fuel

15. Gamma (  ) rays Isotope is contained and stored in pool of water and raised when produce is to be exposed to  -raysIsotope is contained and stored in pool of water and raised when produce is to be exposed to  -rays facility is concrete chamber with 6-12’ thick wallsfacility is concrete chamber with 6-12’ thick walls completely penetrates product and packaging (pallets)completely penetrates product and packaging (pallets)

16. Electron-beam electricity is power source-switch on and offelectricity is power source-switch on and off uses stream of high-energy electrons accelerated at near the speed of lightuses stream of high-energy electrons accelerated at near the speed of light electrons are showered on the productelectrons are showered on the product facilities are shielded with concrete or steel wallsfacilities are shielded with concrete or steel walls penetrates approximately 2-3” of product and packagingpenetrates approximately 2-3” of product and packaging ideal for thin ground beef pattiesideal for thin ground beef patties

17. How ionizing radiation works Electrons disrupt the DNA chain either destroying or preventing reproduction of the organism

20. Factors affecting irradiation effectiveness against microorganisms in foods Growth phase of microorganismGrowth phase of microorganism Type of food (lean vs fat)Type of food (lean vs fat) Moisture content (water level)Moisture content (water level) Temperature of food (frozen vs heated)Temperature of food (frozen vs heated) Presence of oxygen (aerobic vs anaerobic)Presence of oxygen (aerobic vs anaerobic)

21. Irradiation Dosage Dose - amount of energy transferredDose - amount of energy transferred –rad - old unit –gray (Gy) - new unit –1 kGy = 100,000 rad 1 chest X-ray =.01 rad1 chest X-ray =.01 rad natural background = 0.1 rad/yearnatural background = 0.1 rad/year

22. Approximate doses of radiation needed to kill various organisms OrganismsDose (kGy) Higher animals0.005 to 0.1 Insects0.01 to 1 Non-spore forming bacteria 0.5 to 10 Bacterial spores10 to 50 Viruses10 to 200

23. Typical irradiation D-values of pathogens kGy OrganismFresh (refrigerated)Frozen Camplobacter jejuni0.08 – 0.200.21 – 0.32 E. Coli O157:H70.24 – 0.270.31 – 0.44 Staphlococcus aureus0.26 – 0.600.30 – 0.45 Salmonella spp.0.30 – 0.800.40 – 1.30 Listeria monocytogenes0.27 – 1.000.52 – 1.30 D-value is equivalent to radiation dose required to reduce a bacterial population 90%

24. Typical irradiation D-values of pathogens kGy OrganismFresh (refrigerated) Clostridium botulinum spores 1.00 – 3.60 Toxoplasma0.40 – 0.70 Trichinella spiralis0.30 – 0.60 D-value is equivalent to radiation dose required to reduce a bacterial population 90%

25. Destruction of microorganisms Irradiatio nkGy dose 1 D value Contains 10 microorganis ms 1 microorganism survives Irradiatio n kGy dose 2 D value Contains 10 microorganis ms 1 microorganism survives/ 10 steaks

26. Pasteurization To reduce microorganisms but not to sterilize the product Purpose is to destroy pathogenic microorganisms to make food safe This is normally 5 to 7 D values

27. Effect of irradiation on shelf life of fresh meats Spoilage organisms, especially pseudomonads, are susceptible to low dose irradiation Spoilage of low dose irradiated meats may be due to yeast, LAB, or Moraxella spp. (increased lag time)

28. Shelf life extension of fresh meat Meat product Dose kGry Untreated shelf life (days) Irradiated shelf life (days) Beef cuts214-2170 Ground beef1.58-1026-28 Pork loins34190 Ground pork1812

29. How does irradiation food processing operation work? Food is packed in containers and moved by conveyer belt into a shielded room. Food is exposed briefly to a radiant-energy source. (The amount of energy depends on the food.) Food is left virtually unchanged, but the number of harmful bacteria, parasites and fungi is reduced and may be eliminated.

30. Gamma (  ) ray processing facility

32. Electron-beam Dosimeter

33. Levels of Food Irradiation Radurization (low) < 1 kGyRadurization (low) < 1 kGy –vegetable sprouting, fruit ripening, insect sterilization Radicidation (medium) 1-10 kGyRadicidation (medium) 1-10 kGy –kills most pathogens and many food spoilage organisms, kills insects and parasites – Rappertization (high) > 10kGyRappertization (high) > 10kGy –can sterilize by killing all bacteria and viruses

34. Technology Comparison Electron Beam Cobalt-60 Technology Technology Focused beam of electrons (10 MeV energy) Photons created from decay of radioactive material AdvantagesSafe ON/OFF Cost efficient In-Line capability Compact systems High dose rate = reduced oxidation Increased ability to penetrate dense material Process pallet load Disadvantage Reduced ability to penetrate dense material (3 ½ in. of highly dense product – approx. 8 meat patties high) Cannot be turned OFF – always emitting gamma radiation Requires source disposal and replenishment Low dose rate = increased oxidation Consumer perception

35. Meat Irradiation December 23, 1999 Federal Register Effective date – February 22, 2000 Ionizing radiation approved for use –Cobalt-60, Cesium-137, X-ray machines, Electron accelerators Dosage –4.5 kGy if refrigerated –7.0 kGy if frozen

36. Safety and efficacy of food irradiation The following statements are in the Federal Register (12/23/1999) The safety and efficacy of food irradiation, as demonstrated by numerous experiments and studies, is widely accepted by Federal regulatory agencies and national and international food and public health organizations FDA examined numerous studies on the chemical effects of radiation, the impact of radiation on nutrient content of foods, potential toxicity concerns and effects on microorganisms in or on irradiated products. FDA concluded that irradiation is safe in reducing disease- causing microbes in or on meat food products and it does not compromise the nutritional quality of treated products. The World Health Organization, Food and Agriculture Organization, American Medical Association and American Dietetic Association endorse food irradiation

37. Food Irradiation “The Law” Exposure of foods to ionizing radiation in form of gamma radiation, X-rays and electron beams to destroy pathogenic microorganisms In use for over 50 years in European Union US consumers perceptions of effects of radiation prevented widespread acceptance of food irradiation Limited use allowed since 1963 on specific food products for specific purposes.

38. History of Irradiation First documented use of ionizing radiation was to “bring about an improvement in the condition of foodstuffs” and in “their general keeping quality”. British patent issued to J. Appleby and A.J. Miller, analytical chemists British patent No. 1609 (January 26, 1905)

39. History of Irradiation US Army investigates use of irradiation to improve safety and quality of troop diets in 1930 MIT hamburger sterilization study in 1943 Approved by Soviet Union to increase potato consumption in 1958

40. History of Irradiation Approved for potatoes by Canada in 1960 1963 First FDA approval for insect control in wheat flour 1964 - dehydrated vegetable seasoning 1986 - fruit and vegetable ripening 1990 - fresh and frozen poultry to control salmonella and other pathogens

41. Food Additives The term “food additive” means any substance the intended use of which results or may reasonably be expected to result, directly or indirectly, in its becoming a component of or otherwise affecting the characteristics of any food...(and including any source of radiation intended for such use), if such substance is not generally recognized.....to be safe under the conditions of its intended use;”

42. Food Additive Amendment Enacted in 1958 to control use of chemicals in food products First legislation to address irradiation directly Defined all sources of ionizing radiation as food additives (blanket prohibition)

43. Classification of Irradiation as a Food Additive

44. Legal Basis: Deposition of radiolytic byproducts considered “components” of food product. Radiolytic byproduct “affect the characteristics” of the food

45. Scientific Basis: Ionizing radiation produces byproducts (radiolytic byproduct) which interact with and thereby become a component of foods The interaction of ionizing radiation with foods affects the characteristics of foods

46. Factual Basis: Perceived need to inform consumer of all “material facts” about the foods they consume Little understanding of the nature and effects of ionizing radiation in biological systems Inability to identify irradiated products Public reaction “Irradiation = Radioactive”

47. Impact of Classification Requirement for pre-market approval Costly and protracted review process Limited utilization of effective food safety tool Labeling requirement (Radura) Limited opportunity for consumer education and acceptance of irradiated products

48. Statutory Exemptions to Classification Prior Sanctioned substances Approved substances (FAP) Substances generally recognized as safe (GRAS)

49. Generally Recognized as Safe General recognition of safety among experts qualified by scientific training and experience to evaluate its safety No FDA approval required Can petition FDA for affirmation Congressional recognition of “safety” criteria

50. GRAS Criteria What do you need for GRAS status? General recognition of safety through scientific procedures based on published literature GRAS status must be based on same quality and quantity of scientific evidence as would be required for “food additive” petition (FAP)

51. GRAS Criteria Substantial history of consumption by significant number of consumers in the US (”common use”) GRAS status based on “common use” requires lesser quantity of scientific evidence than FAP GRAS affirmation should consider manufacturing process

52. GRAS Examples U.S. v. Articles of food.....Buffalo jerky 456 F. Supp 207 Nebraska, 1978. Affirmed by the 8th circuit in 1979. Buffalo patties adulterated because ingredient (nitrite) not GRAS. Caffeine, GRAS since 1960 Simplesse, GRAS in 1990 Menhaden fish oil, GRAS in1989 Chymosin from recombinant DNA, GRAS in 1990.

53. Self Determination of GRAS Status No requirement for Food Additive Petition Places burden on FDA to prove additive unsafe Avoids costly and protracted FDA approval process Can market product immediately Can seek FDA affirmation of GRAS status by petition

54. Self Determination Criteria: Safety Determination by proponent Common use over a period of time (the “nothing happened” test) Lesser degree of scientific evidence if based upon “common use”

55. Irradiation as GRAS Common useage for over 50 years in US and European Union (nothing happened!) FDA approval is government admission of the safety of irradiation Irradiation does not fit definition of a food additive

56. Irradiation as GRAS Original classification erroneous Radiolytic byproducts products by irradiation are the same as those produced by traditional processing methods whose status as GRAS or as a food additive has never been asserted or challenged. (Heat treatment, freezing) Advances in analytical capabilities have determined nature, quantity and effects of radiolytic byproducts in biological systems

57. Some Examples

58. Nutra-Sweet Aspartyl-phenylalanine-methyl ester Heavily criticized because of delayed submission of negative data Agency insiders retained by industry Caused FDA to adopt “strict scrutiny” of all data submission in support of FAPs

59. Olestra Originally submitted for approval as a DRUG for cholesterol reduction in 1974. Withdrew drug application in 1988 Filed as “fat replacer” in 1988 Not approved until 1996 200,000 pages of data submitted

60. High Fructose Corn Syrup Developed at time as Olestra Marketed as GRAS in mid-60's “Self Determination” of GRAS status Marketed and sold continuously for over 30 years without resort to FDA approval process

61. Benecol New Approach Cholesterol absorption inhibitor FDA alleged Benecol margarine “plant stanol ester” is un-approved food additive Manufacturer alleges Benecol is Dietary Supplement in food form Sold in Finland since 1995 FDA can seize or sue (refer to Dept of Justice) Why not assert “GRAS” status?

62. Approval of Irradiation Recent outbreaks of foodborne illness FDA Modernization Act of 1997 President’s Food Safety Initiatives (Food Safety From Farm to Table) NASA Petitions Isomedix Petition

63. Approval of Irradiation Isomedix petition filed 1994 seeking approval to use ionizing radiation for treatment of beef products. December 1997 FDA approved use of ionizing radiation for the treatment of refrigerated or frozen uncooked meat, meat byproducts and certain meat food products to control foodborne pathogens and extend shelf life.

64. Labeling of Irradiated Foods FDA has required labeling of irradiated food products since 1966 Radura logo required since 1986 Irradiated ingredients excluded Only “First Generation” foods must be labeled Reduces acceptability of irradiated food products because of consumer association with radioactivity and lack of consumer education regarding safety and efficacy of irradiation

65. Labeling Considerations Effect of Irradiation Declaration on acceptance of irradiated foods and food safety generally Does labeling at the retail level ensure the safety of the food product Inconsistent application of labeling requirement (potatoes, wheat flour)

66. Consumer Acceptance Affected by Irradiation label declaration Tested by consumer surveys, limited market testing and retail sales Affected by perception that irradiation equals radioactive 72% of consumers have heard of irradiation but 30% of those think irradiated foods are radioactive (1996 survey) Survey found that education increases acceptanc

67. Food Irradiation “The Science”