Irradiation of Food CASA Annual Meeting2001

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Irradiation of FoodCASA Annual Meeting-2001

• Catherine N. Cutter
• Department of Food Science
• Penn State University

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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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History of Irradiation

• Discovery that uranium is radioactive 1896
• ?-rays found to destroy bacteria in food 1900
• Patents issued for food irradiation 1905
• Electron-beam accelerator invented 1940
• X-rays found to preserve ground beef 1943
• U. S. Army tests irradiation on foods 1950s
• U. S. government approves irradiation
• for wheat flour, potatoes 1963-4
• NASA sterilizes food with irradiation 1970s
• Irradiation approved for herbs, spices,
  seasonings 1983
• Irradiation approved by USDA for control
• of trichinosis in pork 1984
• Irradiation approved for control of insects
• and maturation of fruits and vegetables 1986

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History of Irradiation

• USDA approves irradiation for control of
• Salmonella spp. in poultry 1990
• FDA petitioned for approval of irradiation
• for fresh red meat 1994
• FDA approves irradiation for red meat 1997
• FDA petitioned for approval of irradiation
• for processed/RTE meat and poultry 1999
• USDA approves irradiation for fresh and
• frozen meat 2000
• FDA approves irradiation for eggs 2000
• FDA petitioned for approval of irradiation
• for sprouts 2000
• FDA petitioned for approval of irradiation
• for seafood
  2001

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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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Irradiation.also known as

• Ionizing radiation
• Surface pasteurization
• Electronic pasteurization
• E-beam sterilization/pasteurization

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Electromagnetic Spectrum
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• Gamma (?) rays
• energy comes from decay of radioactive isotopes
  (Cobalt-60 and Cesium-137) short half life25
  years
• isotope is contained and stored in pool of water
  (radiation shield) and raised when product is
  exposed to ?-rays
• facility is concrete chamber with 6-12 thick
  walls
• completely penetrates product and packaging
  (pallets)
• process 200 million lbs/year
• estimate of pennies/lb

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Gamma (?) rays
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Gamma (?) rays
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Gamma (?) rays
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• Electron-beam
• electricity is power source-switch on and off
• uses stream of high-energy electrons accelerated
  at near the speed of light
• electrons are showered on the product
• facilities are shielded with concrete or steel
  walls
• penetrates approximately 2-3 of product and
  packaging
• ideal for thin ground beef patties
• can process 26,400 lbs in one hour
• estimated cost of 0.05/lb for in-plant system
• 0.15/lb for off-site system (product is
  transported to facility, unloaded, unpacked,
  treated, repacked, reloaded)

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Dosimeter
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• X-rays
• energy comes from electrical source that produces
  a beam of accelerated electrons that collide with
  metallic target
• facility enclosed in 6-12 thick concrete walls
• penetrates 12 or more of product and packaging
• process 2,640 lbs/hour
• estimate of gt0.05/lb
• ideal for whole chickens and turkeys

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Dual X-Ray E-Beam System
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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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Biological Effects of Irradiation
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Biological Effects of Irradiation

• Irradiation can directly impair critical cell
  functions or components (DNA)
• Single strand breaks (repairable in most cases)
• Double strand breaks (not repairable in most
  cases)
• Irradiation can indirectly form radiolytic
  products/free radicals from water (oH, oOH)?DNA
  damage

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Factors affecting irradiation effectiveness
against microorganisms in foods

• Growth phase
• Type of food
• Moisture content
• Temperature of food
• Presence of oxygen

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Irradiation Dosage

• Dose - amount of energy transferred
• rad - old unit
• gray (Gy) - new unit
• very large dose 1 million rad 10kGy
• or 1kGy 100,000 rad
• 1 chest X-ray .01 rad
• natural background 0.1 rad/year

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Approximate doses of radiation needed to kill
various organisms
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Effect of Irradiation on Pathogens Population
(log10 CFU/g) - killed by
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Levels of Food Irradiation

• Radurization (low) lt 1 kGy
• vegetable sprouting, fruit ripening, insect
  sterilization
• Radicidation (medium) 1-10 kGy
• kills most pathogens and many food spoilage
  organisms, kills insects and parasites
• Rappertization (high) gt 10kGy
• can sterilize by killing all bacteria and viruses

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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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Current Uses of Irradiation Pharmaceutical/Medica
l

• -Airways and tubes
• Alcohol wipes
• Bandages
• Blood
• Contact Lenses
• Cotton Balls
• Dental anchors, burrs and sponges
• Drug mixing/dispensing systems

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Current Uses of Irradiation Pharmaceutical/Medica
l

• Enzymes
• Eye droppers and ointments
• Fetal Probes
• Instruments
• IV Administration sets
• Liquid detergents
• Lubrication gels
• OR towels

• Petri dishes
• Prostheses
• Surgical Gloves
• Surgical gowns
• Sutures
• Syringes and needles
• Thermometers/cover
• Tongue Depressors
• Topical Ointments

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Current Uses of Irradiation
Consumer Products

• Adhesive bandages
• Animal vaccines
• Baby bottle nipples
• Contact lens cleaning solutions
• Cosmetics
• Dairy and juice containers

• Disposable baby bottles
• Food packaging
• Pacifiers and teething rings
• Pet food
• Rawhide dog toys
• Feminine hygiene products

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Current Approved Dosage for Foods
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Irradiation Facilities

• 36 countries approved irradiation
• 140 irradiation facilities
• 115 for medical products
• U.S.
• 40 irradiation facilities
• Food treatment in US
• FOOD TECHnology Service, Plant City, FL (gamma)
• Titan, Sioux City, IA (e-beam)
• New Jersey (e-beam and X-ray)
• Long Island (x-ray)
• Chicago (e-beam) and Excel plant (e-beam)

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Irradiation Facts

• Irradiation is a cold process that does not
  increase the temperature significantly or alter
  characteristics of the food
• Energy from the process dissipates and does not
  remain in the food
• Nutritional losses due to irradiation are less or
  about the same as cooking and freezing
• Irradiation causes chemical changes in foods
  similar to cooking, toasting, frying, and
  freeze-drying
• Appropriate precautions (refrigeration, proper
  handling, preventing cross contamination) must be
  taken with irradiated product to ensure that
  pathogens do not present a problem

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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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Labeling Requirements of Irradiated Foods
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Treated by Irradiation Using Surebeam
Electronic Pasteurization System
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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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Levels approved for meats

• 0.3 - 1.0 kGy for control of Trichina in pork
• up to 3.0 kGy for control of pathogens in fresh
  or frozen packaged poultry
• up to 4.5 kGy for pathogen control in
  uncooked/refrigerated meat
• up to 7.0 kGy for pathogen control in
  uncooked/frozen meat

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Meat Industry Use of Irradiation

• Only good quality, wholesome meat will be
  irradiated
• Irradiation will not be used to destroy
  pre-formed toxins or viruses
• Irradiation will not be adopted to cover up badly
  contaminated meat
• Irradiation will reduce, and in some
  circumstances, eliminate pathogenic
  microorganisms in or on meat and poultry
  including Salmonella, E. coli O157H7, S.
  aureus, Listeria monocytogenes, Campylobacter
  jejuni, and Toxoplasma gondii

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Meat Industry Use of Irradiation

• When irradiated at certain doses and under low
  oxygen conditions, meat does not exhibit
  off-odors or off-flavors
• Meat color (dark red) can be affected by
  irradiation under vacuum packaged conditions

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Shelf life extension of fresh meat
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Overview

• History of Irradiation
• Types of Irradiation
• Biological Effects of Irradiation
• Current Uses of Irradiation
• Labeling Requirements
• Meat Industry Use of Irradiation
• Consumer Opinions of Irradiation

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Consumer Concerns

• Creation of potentially harmful, chemical
  compounds in irradiated foods
• Loss of nutrients in irradiated foods
• Use of irradiation to conceal contamination of
  spoiled foods
• Exposure of employees to dangerous levels of
  radiation

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Consumer Surveys

• Kansas State Survey
• Mailed educational brochure to consumers
• Followed by questionnaire
• Results
• 75 said they would buy at same
• 55 said they would buy at higher
• - Purchase at Meat Lab
• 70 bought irradiated poultry at same price
• 52 bought if .10/lb higher

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Consumer Surveys

• American Meat Institute Survey
• 54 would buy (after irradiation was explained)
• University of Georgia Survey
• 45 would buy (if labeled)
• 17 would not
• 38 undecided

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Will Consumers Buy Irradiated Foods?

• Strawberries - 1992, over 1000 pints sold in 5
  days in North Miami Beach
• Poultry - 1993, sold out of boneless breasts in
  2 days in Northbrook, IL
• Beef-2000, sold out of ground beef in 4 days in
  Minnesota

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Consumer Opinions of Irradiation

In market trials of labeled irradiated foods
sold alongside the non-irradiated ones, consumers
willingly bought irradiated products, and in many
cases, expressed a preference for the irradiated
product.
results suggest that most consumers would
purchase irradiated meat and that up to 30 of
consumers would pay a premium for irradiated
product.
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Consumer education is important

• There is no health risk
• There is no environmental risk
• It will reduce (nearly eliminate) pathogens
• It will not replace other food safety procedures
• Low levels will not affect palatability
• It will result in a safer product

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Future of Irradiation

• Approval by FDA and/or USDA
• Use of technology for
• RTE foods
• Eggs
• Sprouts
• Seafood
• Combination of irradiation with other
  technologies to reduce pathogens

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QUESTIONS??