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Home My WebLink AboutCOM 0212.336 1996-1998 CAST CC IL FOR AGRICULTURAL SCIENCE AND TECHNOLOG . =ISSUE PAPER ~ l.~~ti~~ _,1~~~~-,~~, NUMBER 7 APRIL 1996 `~,If'41L~ RADIATION PASTEURIZATION OF FOOD AUTHORS: DONALD W. THAYER (COCltair), U. De- pnrnnent of Agriculture. ARS, ERRC. Philadelphia. Pennyslvauia; EDWARD S. JosErxsoN (Cocltairj. L'MDIARY cal Association, the Ameri- Radiation asteuriza- Food Science and Nutrition Research Center. Uni- P can Dietetic Association. [he _ lion of foods with low doses versin~ of Rhode !Bland. West Kingston: ARt Ins[imte of Food Ttchnolo- of gamma rays. X-rays, and gRY~toLFSSO~, Wm(and. Massnchusettsr GEOttce gists, and the health authori- electronswill effectively con- ties of approximately =0 G. GIDOtNCS (Deceased). /ntenmtional Atnrnic En- trol foodbore pathogens on countries. beet. pork. Iamb, and fish. As ergr Agency, Vienna. Austria; REVtewexs: JL•Llcs used here rndiatiort pasteur- VI. Coon, rYLD., Jenkinron, Pennsplvanin: SANFORD INTRODUCTION i;ation means the destruction A D•LLLER. Graduate School of Biomedical Science. Although largely pre- of pathogenic non-spore ventable, foodbome illness formino foodbome bacteria Univecsin• of Tesnr Health Science Center of San remains a serious problem in and parasitic organisms, such Antonio; bloRRts E. POTTER. DV~N. Centers for Dis- the United States. A report b~~ as trichina. Radiation pasteur- rase Control and Prevention. Atlanta. Georgia: the Council for Agricultural iza[ion therefore can protect Science and Technolosy has TANVA RoRERTS. U.S. Deparnnent of Agriculture, - the public from diseases such estimated [hat foodbome dis- cs salmonellosis. hemorrhag- Econronic Research Service: WALTER (IRBAIN. Su° eases caused by pathogenic is diarrhea caused by Esther- Cin•, Ari;,ona bacteria such as Cmnp~ Gr ichia coli 0157:H7, and gas- buc•ter, Escheric6ia cn(i troenteritis from Vibrio vulniftcus. Irradiation can extend O 157:H7. Listeria nvmacytogenes. Snlnvrnelln- and Sta- the shelf lives of fruits and vegetables, and atthropod ph~~lococcus mtreus may Cause as many as 9.000 deaths pests, e.g.. insects and mites, can be sterilized or killed each year and 6.5 to 33 million cases of diarrhea! dis- in amore environmentally friendly manner than is pas- ease in the United Stales- The annual economic losses Bible with ozone depleting, highly toxic fumigants. associated with foodbome disease may be as !arse as 55 Moreover, long-tetm animal feeding studies have dem- billion to 56 billion. Recent outbreaks of disease caused onstrated that radiation pasteurized or sterilized foods by the ingestion of E. tali OI57:H7 in hambureer. par- aresafe and nutritious for humans. The process has been, titularly in the notthwestern United States where there endorsed by by the U.S. Food and Drug Administration were more than 700 cases and four deaths from a sinsle (FDA), the U.S. Department of Agriculture (USDA), the outbreak. have alarmed the public. Unfottunately, this U.S. Army, [he World Health Organization (WHO), the organism may cause 8,000 to ?0,000 cases of disease Codex Alimentarius Commission, the American Medi- annually in the United States. Gc)tnoe ~0. 2 ~ Z.. IniP nD,,FND GI R,^f 'iU:Qf65Bnt6r~~ MAY 0 7 1997 COI. .FOR AGRICULTURAL SCIENCE AND TECNNOLOGV-2 The most comfion foodbome bacterial pa[hogens sne. and [he protozoan parasite Tn.TOplasuxr gondii. Tri- that may be found on meat aril poultry are Cmnp~'lo• c/tinellu spirn[is localizes in the muscles of piss and bacrerjejuni. E..tc6erichiaco/i01~7:H7.Listerinmono- manv wild animals and when inserted by humans can cwogenes. various SnGnnnellu app., and Stnp/n•locnc•cus cause trichinosis. Fortunately. this disease is rare in the nureus. The symptoms of campylobacteriosis caused by United States. Adult tapeworms may be several feet loner C. jejuni generally are a mild diatrhea besinning I to 7 and occasionally infections may resul[ from a[[achment days after inoestian of contaminated food and may las[ of Cpsricercus bovis to the wall of [hr intestine. If the from t to 7 days. Infections larvae emeree within the in- from E. coli 0157:H7 can testine. the}' may penetrate ' cause severe abdominal THE RADIATION PASTEURIZATION the wall: when that happens cramps and pain. bloody dice- the eyes. heart, liter. lungs. rhea, and occasional renal PROCESS FOR MANY FOODS HAS BEEN and brain may become infec[- failure staffing 3 to 7 days APPROVED OR ENDORSED BY THE ed. Other symptoms of infec- after ingestion of the contam- tion may be abdominal pain. inared food. lasing days to MAJOR U.S. AND WORLD AGENCIES nausea, weakness, wri~ht weeks. and possibly resulting AND ASSOCIATIONS. loss, hunger pains, and ner- indeath. Listeriosis caused by vousness. In 1993. T. gondii infection withL. mosoc•croge• caused 2.0.6 cases of food- - nes is an acute infection of the brain with or without ac- borne illness in the United States a[ an estimated cost companyino persistence of the organism in the blood. of 52.7 billion. In most otherwise hra([hy individuals. Symptoms appear suddenly and include fever, intense its associated disease usually is mild and self limiting. headache, nausea. and vomiting. The bloodborne form It can. however, cause diseases ransins from a rash to of [he disease is an acute. mild illness with influenza like hepatitis in adults. Babies may be infected before birth symptoms, which in pregnant women usually results in by cross infection from the mother. These congenital infection of the fe[us and miscarriage. Most foodbome infections sometimes lead to infections of the brain with cases of listeriosis occur among individuals with sup- death occurrine in 5 to f09o of the cases. In those per- pressed immune systems. In these individuals the mor- sons whose immune systems are not functionine at nor- tality rate may reach 13°c; overall it is 309c. Lisrerin mal levels, previously benign infections of Toxoplnsma monoccrogenes can multiply in foods stored at refriger- gondii may progress to encephalitis and other infections anon temperatures. so risk may increase during storage. of the central nervous system. despite proper refrigeration. Salmonellosis, caused by infection with anv of over 2.500 different strains of Snl- THE ISSUe matel(n, is characterized by a mild to severe acute gas- Radiation pasteurization when used in conjunc[ion troenteritis starting 6 to 72 hours after ingestion of con- with proper food processing and prepara[ion techniques. taminated food and lasting for days to weeks, and greatly decreases the probability that foodbome patho- causing fever. pain. diarrhea, nausea, and vomiting. Srn- Bens associated with meat, poultry. and other foods will pln•lococ•cus aureus can produce cheat-stable toxin in reach consumers. improperly stared food that, if ingested, will produce mild to severe symptoms of nausea, cramps, vomiting. Boaster oe IoNtZING R,tuuTtO~ Are[tovED diarrhea. and pros ration in 2 to 7 hours lasting I to 2 eOR FOOD IRIt.4D[AI'IO\ days. The FDA has approved the following sources of Beeti. pork, and other meats sometimes are con-. ionizing radiation for the treatment of foods: samma ra}'s taminated by parasitic organisms [hat may cause disease produced by the natural decay of radioactive isotopes in humans when ingested. Among these arc the parasit- of cobalt-60 or cesium-137, x-rays wi[h a maximum is nematode Trichirtel/n spirnlis, the bovine and pork enerey of five million electron volts t~(eV), and elec- tapeworms Ccsric•ere•us bovis and Cvsricercus ceUulo- [eons with a maximum energy of IO ~IeV. (The elec- CO -FOR AGRICULTURAL SCIENCE ANO TECHNOLOGY-: tron volt [eV] is the`amog4rt=of enemy acquired by an ported before consumption. Most spices are dried in the electron when it is accelerated'by one volt in a vacu- open air and become severely contamina[ed by air- and um.) X-rays are produced when high energy electrons soil-borne bacteria. fungi. and insects. Bacterial pla[z strike a thin metal tilm and are identical in [heir action counts of one to l00 million per gram of spice are not to eamma rays. The term ionizing means that [his form unusual. Many commercial food processors therefore of radiation has sufficient energy to create posi[ice and fumigatz spices with methyl bromide [o eliminate insects negative charges leading [o the death of bacteria and or with zthylzne oxide to eliminate bacteria and mold. other pa[hogens in food. Other forms of radiant znergv Bo[h methyl bromide and zthylene oxide are extremzh include lish[. heat, microwave. and radio waves. toxic. and methyl bromide is pazntially capable of dz- plz[ing the atmospheric ozone layer. Ethylzne oxide has SAFETI' been banned in Europe because of safety and znviron- While food is being irtadiuted it is never in con- mental concerns. and its use for the treatment of eround tact wi[h any radioactive material. and the gamma rays, spice has been reeoked in the United Stales. The U.S. x-rays, or electrons used to treat it cannot make it ra- Clean Air Act and the Montreal Protocol of thz Vienna dioactive. Readers can rela[z Convention require tha[ an} this to personal zxperience substance listed as ozone dz- from exposure to sunlight or MULTIGENERATIGN STUDIES WITH pleting be withdrawn from to beins s-rayed. Althoush ANIIVIALS HAVE DEN(ONSTRATED THAT Production and use by the excessive exposure to sun- year ?001. light and to x-rays can be INGESTION OF IRRADIATED FOODS [S In the United States. harmfuh appropriate expo- COMPLETELY SAFE AND THAT THE spices. herbs. and dry veseta- sure to radiation can be used ble seasonin_ss currently are to kill rapidly growing cells NUTRITIVE VALUE REMAINS treated with ionizing radia- such as those in cancers. It is ESSENTIALLY UNALTERED. lion to eliminate both insects the rapidly growins cells of and bacteria. The FDA has insects or spoilage and patho- approved ionizing radiation genic bacteria that are killzd when food is irtadiu[ed. doses not to zxceed 30 kilogray (kGyi for microbial There is little effect on the food itself because its cells decon[amina[ion of dry or dehydra[ed herbs, spices, and are not multiplying. There are minor effects of radiation vegetable szasoninss that are used in small amounts as on some very sensitive vitamins, e.g.. BI in pork. How- food in~rediznts for flavoring or aroma. (This is a veq ever, it has been estimated that even if all of the pork in mild treatment as a radiation dose of l kGy [1.000 gray]. the United States were to be irradiated, only 3.39c of which represents the absorption of only enough energy vitamin BI in the die[ of Americans would be lost. Also, to increasz the temperature of the product by 0.~3'F.t a small amount of ascorbic acid (vitamin C) in frui[s is Food irtadia[ion is replacing the use of ethylene oxidz converted to another equally usable form of the vitamin. and methyl bromide and is less harmful to the spice [han In fact. multigeneration studies with animals have dem- either heal or ethylene oxide, is more effective agains[ onstrated that ingestion of irradiated foods is complz[e- bacteria than ethylene oxide, and does not leave chem- ly safe and that the nutritive value remains essentially ical residues on products. unaltered. FRGITS AND VEGETABLES SPICES, HERBS, AND DRY VEGETABLE Fruits and vegetables are being irradiated in the SEASONINGS United States ro eliminate insects and spoilage organ- Even though herbs, spices. and vegetable season- isms and [o prevent overripening and in the case of [w- ings are used in small amounts. they may introduce bac- tiers and bulbs. sprouting. The use of ionizing radiation feria sufficient to cause spoilage or foodborne disease with a minimum dose of 0.3 kGy and a maximum dose organisms in food products that must be stored ortrans- nut exceeding I kGy has been approved by the FDA for COUn_,~ FOR AGRICULTURAL SCIENCE ANO TECHNOLOGY--i erowth and maturation inh#bition of fresh foods and for Some varieties of fruit are very sensitive to radiation and disinfestation of arthropod pests in food. [n addition. the skin of the fruit is damased. They therefore may be Japan and other countries that ban the use of chemical poorly suited for irradiation. whereas other varieties of sprout inhibitors, irradia[e potatoes and onions to pre- the same frail respond well. And. too. commodities tend vent sprouting. The shelf life of specialn~, very perish- to be harvested over very short periods. a practice cre- able swee[ varie[ies of onions can be extended to 3 atins huge volumes requiring rapid trea[men[. Very low months. Irradiation of toma[oes not only extends their doses of ionizine radiation can preven[ the emergence shelf life bu[ also allows them to be harvested when fully of adult insects and thereby mee[ treatment demands. ripe. Irradiated mushrooms have a 3-w'eek shelf life Because irradiation leaves no residues. products must without brownine or cap separation. Irradiation ofstraw- be protected from reinfesta[ion after treatment and dur- berries extends their refrigerated shelf life to 3 weeks ino transport. without decay or shrinkage. Irradiated fruit and veleta- Use of irradiation as a quarantine control measure tiles now are available in some U.S. stores. requires approval by both state agencies and the USDA- So the[ insect pests such as the fruit fly are elim- Animal and Plant Health Inspection Ser<ice (APHIS i. mated. fruit from Hawaii and Puetto Rico and from other [f the product is to be exported. the importing country countries must be fumigated or treated by hot water dips coal[ approve [he quarantine process. Because the ap- before being imported into the continental United States. propria[e radiation doses will cause sexual sterility of Even on the mainland. many fruits. grains, and veleta- insect pests. but not necessarily kill them outright. reg- - bles must be fumigated before being transported. stored. ulatory agencies are considering the type of regulations or processed. The primary fumigant used for fruit is needed to achieve quarantine security. Currently, the methyl bromide, which may be banned in ZOOI. Irradi- only applicable U.S. quarantine regulation is for the ir- ationcan replace fumigation for some of these commod- radiation of fresh papaya fruit in Hawaii to prevent fruit hies. Most arthropod pests, e.g., frail flies. codling fly importation to the mainland (Table I). moths. mango and avocado seed weevils. scale insects. Several other fruits that are available in Hawaii. mealy bugs. and mites can be sterilized or killed by very but not on the mainland, have been imported and irta- low doses of radiation. Irradiation is a promising alter- dialed for customer acceptance trials. with excellent native [o methyl bromide as a quarantine trea[men[ for results. The Agricultural Research Service (ARS r. the codling moth on apples. APHIS, and [he food industry are participating in these Just as with other disinfestation techniques. how- trials. and the federal agencies actively are considering ever. the food irradiation process must be optimized for regulations for implementation of radiation disinfesta- the particular variety of fruit and its stage of maturity. [ion. This technology, which for some commodities may Tablet. U.S.approvals (kilograys)torirradlated foods ProduM Agency Date Dose (kGy) Purpose Wheat. wheat Nour FDA 1963 0.2-0.5 Insect disinfestation White potatoes FDA 1964 0.05-0.15 Sprout inhibition Spice and vegetable seasonings FDA 7983 max. 10 Microbialdecontamination pork FDA 1966 0.3-1.0 Trichinainactivation Fruits and vegetables FDA 7986 max.1.0 Insect andlorgrowth and maturation delay Papayafruit USDA 7987 min. 0.150 Insectdisinfestation Herbs, spice, and dry FDA 1966 max. 30 Insectdisinfestationend/or vegetable seasonings microbialdecontamination Dehydrated enrymea FDA 7986 max. 10 Microbialdecontamina6on Animal and pet food FDA 1986 max. 25 Microbialdecontaminatlon Poultry FDA 1990 max. 3.0 Microbiatdecontamination USDA 1992 1.5-3.0 Microbialdecontamination Red meat, nonfrozen FDA Pending max. 4.5 Microbial decontamination Red meat, frozen FDA Pending max. 7.0 Microbialdecontamination J COI ,FOR AGRICULTURAL SCIENCE AND TECHNOLOGY-5 be the only suitablev~nd e_nrironmentally safe replace- contamination. Radiation pasteurized products are nei- men[ for methyl bromide fnrttigation, has the addition- Cher sterile nor shelf-stable and must be properly refri~- al advantage of increasing shelf life by eliminating spoil- erased, cooked, and served. Irradiation serves as one of ace organisms. the processor's final quality control steps, assurine both the processor and the consumer of product safety. An- WHEAT nvu FLOUR other impottan[ advantage of radiation pasteurization of As much as 400,000 tons per year of imported meat and poultry products is that cross contamination of wheat are irradiated with an electron beam to kill insects other products during meal preparation is prevented. Ir- at the port of Odessa, Ukraine. This process was devel- radiation is an effective addition to the overall control oped through U.S. Army/ARS reseazch and approved for of extremely virulent pathogens. e.g.. Escherichia coli use in the United States in 0157: H7, in raw wound 1963 (Table I). It has not jN THE UNITED STATES, SPICES, beef. been used in the United States It is unlikely that all because of the availability of HERBS, DRY VEGETABLE SEASONINGS, meat and poultry products fumigants and physical meth- AND FRUITS AND VEGETABLES ever will be irradiated: ra[h- ods for separating insects er. irradiated meat and poul- fromgrain. All these methods CURRENTLY ARE TREATED WITH try likely will be chosen b}' have advantages and disad- IONIZING RADIATION TO ELIMINATE customers who desire or re- _ vantages, but neither irradia- quire a greater decree of food lion nor physical methods INSECTS, BACTERIA, AND SPOILAGE safety, and by food service leave residuals to prevent re- ORGANISMS. establishments to protect chil• infestation. dren and other hieh risk con- sumers from ~ foodbome BEEF, La,~, PORK, aN0 POIn.TitY pathogens. The largest market for irradiated chicken cur- Relatively low doses of ionizing radiation can be rently is hospitals and nursing homes. Ittadia[ed chick- used for radiation pasteurization treatments of meat or en has sold well, when offered, in retail markets. poultry to control parasites, fungi, and all but the most Research has demonstrated that the number of liv- resistan[ of foodbome pathogens and food spoilage bac- ing cells of rags[ foodborne pathogens, includins E. co(i feria. To control Trichinella spiralu, both the FDA and 0157:H7, can be significantly decreased. and in many the USDA, Food Safety and Inspection Service (FSIS) cases completely killed on meat or poultry, by treatment approved in 1986 the irradiation of fresh or previously with ionizing radiation (Table 2). Radiation doses re- frozen pork to a minimum dose of 0.3 kGy and amax- quired to decrease pathogen numbers by 9090 in beef are imam dose not to exceed 1.0 kGy. Regulations permit- ting poultry irradiation to control foodbome pathogens were approved by the FDA in 1990 and by the FSIS in 199? (Table 1). The FDA established the maximum dose Table 2 Radiation does (kilograys) required to reduce the population of foodboms paNogens by 90% in beef as 3.0 kGy, and the FSIS established the minimum dose at 5°C as l.5 kGy. The FDA is reviewing a petition to allow pathogen Dose (kGy) radiation pasteurization of edible tissue of domesticat- ed mammalian human food sources, primarily beef, Bacuuscereusendospore 2.aezo.3t ork, shee ,and horse. Campylobaaerjejuni G.15-o.20 P P ClosMdiumbotulinumendospore 3.43 ®-30°C The potential for consumer infection by patho- Escbedchiacoli0i57:!-17 G.3oxo.o2 gens is decreased greatly and shelf life is extended by t.ISredamonocytoganes o.a5 xD.o3 Selmonellaspecies 0.70 z 0.04 radiation pasteurization of meat and poultry. This ben- Stapby~oeoccusaureus O.aS x O.oz efit can be achieved only if [he highest-quality products , Salmonella dublin, S. enrenn'dis, S. newport, S. senttenberg, are irradiated, preferably after packaging, to prevent re- ands. lypbimudum. COUNCIL FOR AGRILULTUFAL SCiEPICE AND TE~4NOLOGV-8 listed in Table The parasitfCnema[ode Trichinella Cnlnp~lobacrer. 99.999+90 of E. coli O157:H7 (Figure spiralis. the bovine and pork tapeworms Cvsticercus I 99.9+9c of Snbnonella (Figure 1), and 99.999+9c of bons and CysriceruLS celkdosae, and the protozoan Sraph~dococcus cells would be killed. These results were parasite To-[oplasma goltdii are all inactivated by ion- calculated assuming irsadiation at a temperature of 4l'F. izine radiation doses below 1.5 kGy. Escherichia coli Further. for Snlnronella. a rather high resistance value OI~7:H7, Lisreria monocvtogenes. Salmonellae spp.. of 0.70 kGy was used for Salmonella based on [he radi- Srapln•/ococcus aureus, and other foodbome bacterial a[ion resistance of a mixrure of five Salmonella strains. pathogens can be eliminated or decreased significantly Some strains of Salrnolrella are much less radiation re- in number by treatment of meaz or poultry with Pasteur- sis[ant than [his mixture and when present in foods such izine ionizing radiation doses above LS kGy but below as eggs. which have higher water contents than meats l0 kGy (Table 2). do. will be even more sensitive to irradiation. Submis- The approved minimum ionizing radiation dose lion of a petition to [he FDA and USDA to approve low for treatment of poultry is LS kGy. and [he maximum dose irsadia[ion (0.6 to LS kGy) to control Salmonella dose is 3.0 kGy. The FDA currently is considering a infections in fresh whole ergs in intact shells is pend- pe[ition from industry for approval to irradiate nonfro- ing. zen red meats with a maximum dose of ~+.5 kGy and In general. the radiation sensitivities of a bac[eri- frozen red meats with a maximum dose of 7.0 kGy to al pathogen in meat and in poultry are not substantially control foodbome pathogens. Le[ us assume that a tar- different. Addition or removal of substantial amounts of eel dose of 2.5 kGy might be chosen for the irradiation water or of salt, however, may alter the radiation sensi- of beef. Such a large[ will be set so that the minimum [ivi[ies of pathogens in processed meat or poultry. Ac- and maximum doses received by the product rage[ rag- tool number and percentage of cells that will be killed ulatory requirements. If the majotiry of the product re- by irradiation depend on various factors such as pa[ho- ceived 2.5 kGy, then approximately 99.9999+9c of gen. growth stage, absorbed radiation dose, irsadia[ion- time temperature, oxygen presence, and water conrent. Resistance of bacterial pathogens is substantially greater 99.999999 at freezing temperatures: these effects, however, have gg_ggggg been determined for most pathogens and are considered E. coli 0157:H7 Salmonella 99 9999 in the selection of appropriate radiation doses. Bacteri- al pathogens differ considerably in their sensitivity to 9x'999 ionizin_s radiation, and spore-forming bacteria and food- Y ~ gg,gg rREATEO ar borne viruses are substantially more resistant than are O1 purely vegetative forms of bacteria (Table 2). c 99.9 . a s9 V Spore-forming bacterial pathogens of the genera InnAOUnoN ~ Bnc•illus and Clostridium are more sensitive to heat af- ro ELIMINATE 90 pq~0~g ter irsadia[ion even though the actual numbers may be o affected only slightly by pasteurization doses of radia- O 1 2 3 fiadiatlon dose (kGy) tion. The Few nonspore-forming bacteria that may sur- vive irradiation are injured severely and become much Figure 1. Tha percentage ofEseherleAlaeoN0157:H7orSal more sensitive to heat. They are, therefore. very unlikely monella contaminating meet or poultry by treat- ment with ionizing rodiatlon doses of 0 to 3 ki- [o survive cooking. lograya (kGy) at a temperature of 41 °F. Ths symbol at the lower right of the figuro is the rodura symbol FI$H AW $FIELLFISH thathas been adopted lnternationallyasalabel for Fish and shellfish are significantsourcesoffood- ircadlatedfood.ln addition, the U.S. FOOd and Drug borne pathogens. And irradiation has been demonsVat- Adminlatratlon rsquirea that the label Include the words"treated with rodiation"or•'treated byirrodi- ed to control Salmonella. Shigella, Staphylococcus au- Atlon" and "keep rofrigerotetl" or "keep frozen." reaas, en[eropa[hogenic Escherichia coli, Vibrio COU FOR AGRICULTURAL SCIENCE ANO TECHNOLOGY-7 cholerne, V. parahaernoAricRS, V. vubtificas, and hep- foods that can be stored for extended periods of time at otitis A virus. which all hale liven associated with fish room temperature without spoilage. The shelf-stable and shellfish. Vibrio vubtifrars may cause gasvoenteri- product is excellent for use by immunocompromised tis or septicemia, which has a mortality rate exceedin_ patients. campers. yachters. astronauts. and military per- ~04"c. This pathogen is associated primarily with the in- sonnet Apollo l7 astronauts ate radiation sterilized ham ~es[ion of contaminated raw oysters. on the moon. Radiation-sterilized. shelf-stable beef steak Frequent oyster contamination led the FDA in and smoked turkey are being consumed by astronauts. 1985 to advise against consumption of raw or under- and with permission of the FDA. U.S. hospitals have cooked seafood by people with hepatic disorders: this used such products. Radiation sterilized meals and meal warning has affected the U.S. shellfish indusw adverse- components are marketed commercially in South Airi- ly. Recent data have shown [hat ionizing radiation dos- ca and are used by the South African military forces. The es of only I kGy are adequate [o eliminate Vibrio vubtifi- South African process is very similar to that developed crrs in oysters. When combined with a traditional by [he U.S. Army Natick Research and Development depumtion, or controlled purification, treatment, radi- Center. The only sterile, shelf-stable meat and poultry anon doses of 2 kGy were demonstrated in 1991 to de- products available commercially in the Cnited States are crease significantly the number of hepatitis A virus in canned (thermally processed) products. clams and oysters. Radiation sterilization allows preparation of meat Although irradiation's ability to control foodbome and poultry products with flavor and texture character- - pathogens in fish is well established. [here is a concern istics different from [hose of thermally processed prod- that marine fish might becon- ucts. The techniques used to laminated with Clostridium RADIATION PASTEURIZATION WHEN Prepare sterile food by irradi- bondinum type E, which can a[ion differ greatly from those grow at refrigeration temper- USED IN CONJUNCTION WITH PROPER used in radiation pasteuriza- atures as low as 38°F. As FOOD PROCESSING AND PREPARATION lion. In sterilization. [he radi- mentioned. C. borulinum is anon dose must ensure elim- relatively resistant to radix- TECHNIQUES, GREATLY DECREASES THE ina[ion of [he most resistant lion and will not be affected PROBABILITY THAT FOODBORNE bacterial pathogen- Closn•id- signiticandy by pasteurize- ium 6ondinunr. Because this lion doses: if contaminated ir- PATHOGENS ASSOCIATED WITH MEAT, is a very large dose-approx- radiated fish are sealed in POULTRY, ARID OTHER FOODS WILL imatety 1? to i 1 kGy depend- oxygenimpermeable packag- ing on the product, it must be es. C. 6onrlinum type E may REACH CONSUMERS. delivered to a vacuum pack- thrive because of decreased aged and deeply frozen prod- competitionfrom other bacteria. The product then would uct to avoid flavor change and nutrient loss. The dose become toxic without the usual signs of spoilage. This selected is twelve times that required to kill 909c of the seems an unlikely event. however, considering the rar- endospores of C. boruli»trrn. [f the product is intended ity of C. burulinrrrn type E and the availability of oxy- to be shelf stable then it must be cooked, that is blanched, gen-permeable packaging materials. before irradiation to inactivate the meat's natural en- zymes. Ifthis is not done, the product will spoil through STERILE PRODUCCS biochemical, enzymatic action. Prior cooking improves Two types of food products require sterilization the Flavor of radiation sterilized meat and poultry. mtherthan radiation pasteurization. The first iscornmer- Excellent radiation sterilized. shelf-stable mixed ciall~~ sterile foods, which require itmdiation while fro- vegetable and meat products are available on the South zen. must be stored frozen. and are intended for con- African retail market. Several radiation sterilized, shelf- sumption by the severely immunocompromised patient. stable foods used are well accepted by the South Afri- The second is both sterile ar[d shelf-stable foods. or can military forces in the field. COUNCIL FOR AGF~ICULTURAL SCIENCE AND TECHNOLOGY-e i ' PRODCCT FYCCEPTANCE the water when materials are [o be irradiated, and the An unfortuna[e misconception is [hat the Ameri- food is passed throush the radiation Held. A maze con- can public will no[ accep[ irradiated food. Bo[h atti[ude s[ructed of thick concrete walls, numerous safety inter- studies and market tests hate demonstrated the con[rary. lock systems. s[rict operating procedures. and proper i.e., when the consumer is trainins prorect workers from provided accurare informs- radiation. A typical commer- RECENT MARKET STL'D[ES HAVE tion about produc[s and a cial irradiation plant design is choice between irradiated and INDICATED THAT INFORMED shown in Fieure 2. nonirradiated food. In fact. Electron-beam and e- CONSUMERS ARE WILLING TO PAY A recent studies have indicated ray genera[in~ systems also that informed consumers are PREMIUM FOR IRRADIATED POULTRY can be used for food irradia- willin_ to pay a premium for tion. Several such plans in A;~ID PORK. irradiated poultry and pork. the United Stales are used pri- marily for the sterilization of TECHNOLOGY medical supplies. These systems also must provide sie- Technologies and types of equipment required to nitican[ a[nounts of shielding during operation. but re- irradiate food are identical to those used [o sterilize med- quire none when tamed off. Electron-beams. however. ical supplies. (See Table 3 for examples of medical items have eery low penetm[ion ability and cannot be used for and consumer roods currently sterilized by irradiation.) irradiation of thick materials. An electron-beam system Many commercial irradiation plants exist in the United is used commercially in France to irradiate minced Stales. and they have established an excellent safety chicken meat. Within an aseptic packagins system. losv- record. Commercial plants using cobalt-60 as the source power E-beam sycrPms may be suitable to treat such of radiation store it underwater when it is not in use. items as sinL~le patties of hamburger This technology Cobalt pellets are encapsulated twice in stainless steel may be practical because the mdia[ion dose can be de- tubes arraneed in racks. These rucks are withdrawn from livered to the product very rapidly. A new type of self- Table 3. Examples of items currently eterillzed with ionizing radiation MedicaVPharmaceuticalProdacts Airways and tubes Intravenous administration sets Alcohol wipes Liquid detergents Bandages Lubrication gels Slood Operating room towels Contact lenses Petri dishes Cotton balls Prostheses (arterial, vascular, orthopedic) Dental anchors, burrs. and sponges Surgical gloves Drug products Surgical drapes and gowns Drug mixing/dispensing systems Sutures Enrymes Syringes and needles Eye droppers and ointments Thennometerslcovers Fetal probes Tongue tleprossors Instruments Topieal ointments Consumer Products Adhesive bandages Disposablenurser bottles Animat vaccines Food packaging Baby bottle nipples Pacifiers and teething rings Contact lens cleaning solutions Pet food Cosmetics Rawhide dog toys Dairy and juice containers Tampons CD' .FOR AGRICULTURAL SCIENCE AND TECHNOLOGY-t contained irradiator desionetlto use cesium-137 and suit- Nations Food and Agricultural Orsanization, the WHO. able for use by small andmedium-sized food process- and the Codex Alimentarius Commission suppott the use ing plants is being developed. The term self-caunised of the technology for preservation of wholesomeness of indicates that [he radiation source is never exposed. In food. addition, both commercial and research organizations are actively developing electron-beam and x-ray gen- REFERENCES ermi0? equipment [ha[ may be Suitable fOr fOOd prOCCSS- Ama, A. A.. VI. K. Hamdy. and R. T. Toledo. 1991. Effects of heating. ing plants. Design and operation of food irradiators are PH and Ihennomdiuion on inactivation of Vibrin cuGrijicus. Fond .N(crobiol. I I I S-?.7. regulated strictly by state and federal agencies. American Dietetic Association. 1996. Position of ehe American Die- [e[ic Association: Food irradiation. J..{rn. Dirrrric ,issue. ENDORSEMENTS 96l I ):69-72. Bruhn. C M. 1995. Consumer u[titudes and market response [a irtadi- The FDA has approved the irradiation of pork, ated food. J. Food Pror. 58:175-Isl. poultry, fruits, vegetables, spices, dry vegetable season- Clavem. R. s.. o. Monk. L. R. Beuchm. )l. p. Doyle. and R. E. Ings. wheat, and wheat flour for general use, and shelf- Brakett. 1991. Inactivation of Escherrcbin tali 0157:H7, salmo- stable steak and smoked turkey for use by astronauts. nellae. and Cnnrpylnhncrrr jejuni in raw .round beef by samma irtadiation. App(. Enriron. Microbio(. 60:'_069-?075. The USDA has approved regulations for irradiation of Council for Agricultural Science and Technology. 1986. /mri;ing En- pork, poultry, and papaya fruit. The U.S. Department of rrge in Fnod Processing and Prsr Control: L WGo(erornenrss of Health and Human Services, the U.S. Public Health Food Trrarrd with/onicing fnergr. Report So. 109. Council for Agricultural Science and Technology. Ames. Iowa. 50 pp. Service, the U.S. Army, the National Association of Council for Agricultural Science and Technology. 1989. lonicirrg En- State Departments of Agriculture, the American Medi- rrge br Fr„n/ Pr„<r:.rir~4 n,~d P::r C~nrmc r/..tpp(icudor~r. Ra- cal Association, [he American Dietetic Association. and port No. I I5. Council for Agricultural Science and Technology. the Institute of Food Technologists have endorsed irra- Ames, Iowa. 9s pp. diction technology to enhance food safety. The United Council for A¢ricultural Science and Tahnolooc. 1995. Foodbome Radiation shield Conveyor system Unloading processed product Irradiation 1, , room } y~ 11 ~11~.;,,1, I ~1\ll~~c'~ 1~1'~~~`~; Control console 1 ~~~1`' i ~,~,al~\'~!,i Storage Loading pool Radiation source Figurs 2. Atypical cobalt-8o commercial irradiatlonfacility. Severe) other designs ors used eommareially.Illustration courtesy of Nordion Intemationel, Inc., Kanats, Ontario, Canada. CO. ,L FOR AGRICULNRAL SCIENCE ANO TECHNOLOGY-1L AMERIGN ACADEMY OF VETERINARY AND COMPARATIVE TO%ICOLOGY Pathogens: Risks Qlld CU4sC- AMERICAN AGRICULTURAL ECONOMICS ASSOCATION •AMFAICAN ASSOCIA- Thayer. D. W.. G. Boyd. J. B. FUX. quences. Report NO. I21. TION FOR AGRICULNRAL EDUCATION • AMERICAN ASSCCIATIINJ OF CE- Jr., L. Lakri[Z. and L W. Hamp- 000DCtI fOr AYDCUIfUr1I $Co- RHAL CHEMISTS • AMERICAN DAIRY SCIENCE ASSOCIATION • AMERICAN son. 1991. Variations in radia- ence and TCChDOI08y. Alllet. FORAGE ANO GRASSUNO COUNCIL • AMERICAN MEAT SCIENCE ASSDCIA- n00 sensitivity of foodborne Iowa. 87 pp. TwN • AMERICAN METEOP.OLOOICAL SOCIETY • AMERICAN PEANUT RE- palhOgens at50Cta[ed with [he Diehl. 1. F. and E. Josephson. 1991. SEARCH AND EDUCATION SOCIETY • AMERICAN PHYTOPATHOLOOICALSOCI- SUtpending meat. J. FOOd $c'i. A55¢tsmen[ Of «'`'~IttOmenetS • pMERICAN SOCIETY FOR HORTICULTIIRK SCIENCE • AMERICAN 50- 60:f13-fll. Of Irtadia[ed foods. Acra A/i- CIETY OF AGRICULTURAL ENGINEERS •AMFAIGW SOCIETY OF AORONOMV U.S. Departmtn[ Of AEIICUIWR. INPltfarla 23:195= Il. •AMERICAN SOCIET/OF ANIiMLSCIENCE •AOUATIC PLANT MANAGEMENT FOOd $ately and Impec[ion Diehl. f. F. 1995. Snfrn' of /rmdinted ~I~, • ASSOCIATON OF DFRDIAL SEED ANALYSTS • CROP SCIENCE $eNICC. 1992. IrtldlallOn Uf FOOtIs. 2nd ed. Marcel DtkkeL SOCIETY OF AMERICA • INSTITUTE OF FOOD TECHNOLOGISTS . INTERNA- poulW products. Frd. Re¢isr. IDC.. Ne W York. 1S1 pp. TONAL SOCIETY OF REGULATORY TO%ICOLOGY AND PHARMACOLOGY • 57:135RR~3600. Josephson. E. S. and M. S. Pherson U.S. Departmentof Agriculture. An- NORTH CENTRAL WEED SCIENCE SOCIETY • NORTHEASTERN WEED SCI- IEds.l. 1982. 1983. Preserver- imal and Plant Health Insptc- ENCE SOCIETY POULTRY SCIENCE ASSCCIATON • RURAL SOCIOLOGICAL [ion of Food by lonizina Radio- Lion Strvice. 1987. Uu of irta- [ion. Vol. 1.. 378 pp.: Vol. [L. SOCIETY • SOCIETY OF NEM1NTOLOGISTS SOIL ANO PLANT ANALYSIS dlatl0o aS a quarantine treao- 313 pp.; Vol. ILL. 375 pp. CRC COUNCIL • SOIL SCIENCE SOCIETY OF AMERICA • SOUTHERN WEED SCI- meat fof IRSh fN16 Of papaya Press. [ne..Ba;a Raron. Florida. ENCESOCIETY•WEEO SCIENCE SOCIETY OF AMERICA•WESTERN SOCIETY fiom Hmvad. Fed. R¢gisr. Lee. P. 1991. Editorial. J. Am. Mrd. OF WEED SCIENCE 52:29'-'96 Assoc. 2'_(1):'_61. U.S. Depanmen[ of Agriculture. MaIIeR. I. C.. L. E. Beghian. T. G. Food Saftry and Inspection Metcalf. and J. D. R:avlor. 199E Service. 1986. Irradiation of Potential of irradiation technol- pod: fur convDl of Trichinella- agv for improved shellfish San- THE HLSSION OF THE CDt:VCIL FOR AGILICCLTLtIAL Sl'IE]ICE spun/ir. Frd. Rrgir'f. $I:I',69- itation. J. Food Saferr 11:231- 1771. AHD TECHNOLOGY (CAST) is to idenrifvfoorl aadfrber. envirom 215. U.S. Food and Drug Administration. Thayer. D. W., f. P. Christopher L. A. mensal, and other agriculnval isms mid ro inarprer referred 1990 Irtadiation in the produc- CampbelL.D. C. Ronning. R. R. scienti~ ••^^•A'njormaziaafoelegis(atorr, rcgnlarort. Ord Nte Lion. processing, and handlinE Dahlgrcn. G. M. Thomson, and media involved in public policy decision making. CdS7-is a non- of food. Fed. Regise 55:18538- E. Wierbicki. 1987. Toxicology profs orgarti:arion composed of 30 sciemifrc socirriet and many 18511. studies of irradiation sterilized Urbain. W. M. 1986. Fam! lrmdia- chicken. J. Forxl Pror. 50:278- mdicidual. student. company. nonprofit, and associnre socirn~ rion. Academic Press, lac.. Or- 283. mrmbers.CAST'r Board ofDirectorr it canposed ofdlf represert- Lando. Florida. 351 pp. Thayer D. W. and G. Boyd. 1993. rarivrs of the tcienrific societies and indiridaul mrmben, and an Elimination of Eschrricltia co/i OI57:H7 in menu by gamma ir- Erecuhve Conunirtre. CAST Rnr vtablishrd in ! 972 as a result of radiation. Appl. Enriron. Micro- a meeting sponsored in 1970 by the National Academe of Sciences. Additional copies of this issue paper biol. 59:1030-1031. National Research Council. 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