Food Irradiation Helping Improve Food Safety The UW Food Irradiation Education Group

Why Food Irradiation? Food Safety In 1999, food-borne disease was responsible for:† 76 million illnesses 325,000 hospitalizations 5000 deaths $6-30 billion impact Recent news stories... † According to US Center for Disease Control

Why Food Irradiation? Global Food Supply Approximately 25% of worldwide food production is lost after harvesting due to insects, bacteria and spoilage† Economic losses of $5-17 billion annually in the US alone In the news now…. † According to UN Food and Agriculture Organization

What is Food Irradiation? New commercial technology to eliminate disease-causing germs Comparable to heat pasteurization Used for decades in NASA space missions already used for sterilization of: medical devices, supplies and implants wine corks and other food packaging materials cosmetic ingredients Single slide introduction to process

How Does Food Irradiation Help? food is exposed to carefully controlled amounts of radiation radiation damages DNA of microbes and parasites disease-causing germs are reduced bacteria which cause spoiling are reduced sprouting is slowed or stopped

What are the Results of Food Irradiation? When used in conjunction with proper food handling procedures: food-borne diseases are reduced or eliminated shelf-life is increased the nutritional value of the food is preserved the food does not become radioactive dangerous substances do not appear in the foods

What Foods Can Be Irradiated? Approval Year Food Purpose 1963 Wheat Flour Control of mold 1964 White Potatoes Inhibit sprouting 1986 Pork Kill Trichina parasite 1986 Fruit and Vegetables Insect Control Increase Shelf Life 1986 Herbs and Spices Sterilization 1990(FDA) 1992(USDA) Poultry Bacterial pathogen reduction 1997(FDA) 1999(USDA) Meat

Puchasing Irradiated Food? All irradiated products must be marked with the “Radura” Irradiated meats expected to be more widely available this summer If interested, ask your local grocery retailer

Benefits of Food Irradiation decreased incidence of food-borne illness reduced spoilage in global food supply increased level of quality assurance in international trade of food products Single slide summary of social benefits - related to previous slide on motivation.

Food Irradiation Facilities SOURCE HOISTS SOURCE PASS CONVEYOR UNLOADING ELEVATOR IRRADIATION ROOM CONTROL CONSOLE LOADING ELEVATOR JS8900 UNIT CARRIER IRRADIATOR

Three different energy sources electron beams a beam of electrons is accelerated by an electron gun similar to a TV tube, accelerating electrons towards the screen it can be turned on or off since it uses no radioactive material, but… electron beams can only penetrate about 1” into material

Three different energy sources x-rays generated by directing an electron beam at a thin metal plate similar to medical x-ray sources

Three different energy sources gamma rays emitted from spontaneous radioactive decay “pencils” of naturally occurring non-radioactive cobalt metal (59Co) neutron bombardment in reactor to produce radioactive cobalt (60Co) “turned-off” by lowering Co source into storage pool

Effects of radiation How it kills bacteria radiation damages DNA of organisms if the damage is not automatically repaired the organism will be unable to replicate itself chance of DNA damage related to size of DNA irradiation more effective on bacteria than viruses This information could easily, if tangentially/inappropriately, raise issues of low-level radiation effects on living organisms. Differences: large organisms can afford to have some individual cells die without harmful effects - it is, in fact, part of the process of life this is the reason that radiation is damaging at high doses - it kills more cells than the organism can handle (a related curiosity: Is the single-celled equivalent of cancer basically the creation of a new species? Is this an interesting or relevant issue?)

Effects of radiation Effect on Food most food is made up of dead cells DNA damage is irrelevant living cells cause sprouting and spoilage DNA damage delays spoiling and prevents sprouting longer shelf-life

Effects of radiation Side-effects Nutritional effects macronutrients - proteins, carbohydrates, fats - unaffected micronutrients - vitamins - some reduction comparable to other processing or storage techniques including pasteurization, canning, or even cold storage No change in taste

Costs of Food Irradiation Like any food process, irradiation will add to the cost of the food initially 2-3¢/lb for produce, 3-5¢/lb for beef expected to decrease as it becomes more common Typical food irradiation plant: $3-5 million compare to moderately sized pasteurization plant: $2 million small vapor-heat treatment for fruits: $1 million

Safety of Irradiation Facilities Over 30 yrs of experience 100+ medical sterilization plants medical radiation treatment centers bone marrow transplant centers No public exposure to radiation Independent regulators: gamma rays: NRC X-rays & e-beams: FDA

Facility Accidents and Waste Severe accidents are not possible electron beam and x-ray sources can be easily turned off gamma ray sources cannot blow up The facility itself cannot become radioactive no radioactive waste used Co-60 gamma sources can be recycled/regenerated

Food Irradiation as Part of Comprehensive Food Safety food irradiation is not a replacement for comprehensive food safety in particular, food irradiation cannot reverse the spoilage process irradiated foods need to be stored, handled and cooked in the same way as unirradiated food

Benefits of Food Irradiation disease-causing germs are reduced or eliminated the nutritional value of the food is preserved decreased incidence of food-borne illness reduced spoilage in global food supply increased level of quality assurance in international trade of food products

Food Irradiation Means Safer Food The UW Food Irradiation Education Group http://uw-food-irradiation.engr.wisc.edu uw-food-irradiation@engr.wisc.edu

Radiation dose the quantity of radiation absorbed by the food measured in Grays (Gy) 1 Gy = 1 Joule absorbed per kilogram of food international health and safety authorities have endorsed radiation levels for food up to 10,000 Gy (10 kGy)

What Foods Can Be Irradiated? Approval Year Food Dose (kGy) Purpose 1963 Wheat Flour 0.2-0.5 Control of mold 1964 White Potatoes 0.05-0.15 Inhibit sprouting 1986 Pork 0.3-1.0 Kill Trichina parasite 1986 Fruit and Vegetables 1.0 Insect Control Increase Shelf Life 1986 Herbs and Spices 30 Sterilization 1990(FDA) 1992(USDA) Poultry 3(FDA) 1.5-3(USDA) Bacterial pathogen reduction 1997(FDA) 1999(USDA) Meat 4.5