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Louisiana Agriculture, Spring 2000 1

Spring 2000Vol. 43, No. 2

Food Safety Issue

Spring 2000Vol. 43, No. 2

Food Safety Issue

2 Louisiana Agriculture, Spring 2000

EDITORIAL BOARD:David J. Boethel (Chairman)Linda Foster BenedictPat BollichJames ChambersBarbara Groves CornsJane HoneycuttJeffrey W. HoyRichard F. Kazmierczak Jr.James A. OtteaDavid Sanson

Published quarterly by the LouisianaAgricultural Experiment Station,Louisiana State University AgriculturalCenter, Baton Rouge, Louisiana.Subscriptions are free. Send requestsand any comments or questions to:

Linda Foster Benedict, EditorLouisiana AgricultureP.O. Box 25100Baton Rouge, LA 70894-5100

phone (225) 388-2263fax (225) 388-4524e-mail [email protected].

www.agctr.lsu.edu

EDITOR: Linda Foster Benedict

COPY EDITOR: Jane Honeycutt

PHOTO EDITOR: John Wozniak

DESIGNER: Barbara Groves Corns

The mention of a pesticide or use of a tradename for any product is intended only as areport of research and does not constitute anendorsement or recommendation by the Loui-siana Agricultural Experiment Station, nor doesit imply that a mentioned product is superiorto other products of a similar nature notmentioned. Uses of pesticides discussed herehave not necessarily been approved by govern-mental regulatory agencies. Information onapproved uses normally appears on the manu-facturer’s label.

Material herein may be used by the press, radioand other media provided the meaning is notchanged. Please give credit to the author and tothe publication for any material used.

Louisiana State University AgriculturalCenter, William B. Richardson, Chancellor

Louisiana Agricultural ExperimentStation, R. Larry Rogers, Director

The Louisiana Agricultural ExperimentStation provides equal opportunities

in programs and employment.

Scientists develop processthat saves oyster industry

A partnership between scientists at the LSU Agricultural Center and entrepreneursin Louisiana’s oyster industry has resulted in a revival of the Gulf Coast raw oyster.Louisiana had been a key supplier of this product. But its marketing was threatened byfears that a deadly microorganism, named Vibrio vulnificus, might be lurking inside theshell. The U.S. Food and Drug Administration had required the oysters to carry a warning– strong enough that people did not want to buy them. Research scientists with the LSUAgCenter’s Department of Food Science in cooperation with an industrial firm,AmeriPure Oyster Processing Co., solved the problem. They came up with a heatingprocess, similar to the pasteurization of raw milk, that killed the offending microorganismwithout hurting the texture or flavor of a raw oyster. The process works so well thatthe FDA has lifted the warning label on pasteurized raw oysters. AmeriPure owns thepatent for the process.

Dr. Douglas Park, left, headed a team of scientists that worked with private industry todevelop a pasteurization process for raw, in-shell oysters. The oysters are rendered safe toeat with no harm to their flavor or texture. At his right is the renowned musician PeteFountain from New Orleans, who helped take part in the event at the state capitol.

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The LSU AgCenter sponsored an event at the state capitol in the spring of 1998 to helpacquaint people with the various research activities of the Louisiana Agricultural ExperimentStation. The oysters being served have been pasteurized using the procedure developedthrough research. Left to right are Noble Ellington, John Koch, Nick Felton, Charlie Smithand Michael “Hollywood” Broadway of the Acme Oyster House in New Orleans.


Scientists develop processthat saves oyster industry


Volume 43, Number 2, Spring 2000Page 5

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SCIENCE NOTES

4 The Concept of Food Safety: An OverviewDouglas L. Park and Carlos E. Ayala

6 Training Program Helps Keep Seafood SafeMichael W. Moody

8 New Bar Code Will Help Monitor Food SafetyCarlos E. Ayala and Douglas L. Park

9 Scientists Develop Rapid, User-friendly Test Kit for Marine ToxinsDouglas L. Park and Carlos E. Ayala

11 Consumers Approve Mandatory Country-of-origin Labeling of Freshor Frozen Beef: Louisiana First to Require InformationAlvin Schupp and Jeffrey Gillespie

12 Ozone: New Weapon for Fighting Food HazardsJoan M. King and Terry Walker

15 Safety and Soft-Ripened, French-Style CheesesJackin N. Nanua and John U. McGregor

20 Managing Aflatoxin Contamination in Corn: Scientists UseIntegrated Approach to SolutionJoan M. King, Terry Walker, Henry Njapau, Douglas L. Park and Kenneth E. Damann Jr.

22 Foodborne Illness: Are You at Risk?Evelina Cross and Maren Hegsted

10 Introducing ‘Earl’: Scientists Develop New Rice Variety

16 Pathogenic Microorganism Hazards with Reduced Oxygen Packagingof Ground BeefChung Ping Ho, Kenneth W. McMillin and Nai Yun Huang

17 Influence of Display Gas Mixture on Shelf Life of Ground Beefin Modified Atmosphere PackagingChung Ping Ho, Kenneth W. McMillin and Nai Yun Huang

18 Inhibition of E. coli in Ground Beef Patties with OzoneBrian S. Smith, Kenneth W. McMillin, Thomas D. Bidner and Arthur M. Spanier

19 Safety and Properties of Precooked Pork Roasts with Sodium Lactateand Sodium TripolyphosphateDean J. Antie, Kenneth W. McMillin, J. Samuel Godber and Douglas L. Marshall

Cover photo by John WozniakLSU AgCenter researchers are working on ways to keep the hamburger supply safe byusing ozone. See page 18. More about this research will appear in the Fall 2000 issue.


An Overview ood consumption plays two roles

in human development: nutrition anddisease prevention. Foods provide notonly protein, fats, vitamins, minerals andother constituents essential for growth,but also components necessary forprevention of certain diseases. Forproper growth and mental development,people must eat a balanced diet. Food isboth abundant and generally recognizedto be safe, but some human illnesses canbe traced to foods. The causes of theseillnesses may be natural constituents offoods, such as contaminating pathogenicbacteria, or chemicals in minute amountsthat have been added for other purposes,such as pesticides for insect controlbefore harvest or food additives forenhancing food quality and safety.

Illnesses associated with foods arerare. When they occur, however, theadverse effect on human health and thefood supply availability can be signifi-cant. Studies conducted in researchlaboratories play an important role inidentifying the sources of foodbornehealth risks and the development ofprocedures and products that reduce themagnitude and significance of foodbornehazards. These studies help provide theassurance of a safe, wholesome foodsupply. Industry, academia and publichealth agencies work hand-in-hand toreach this goal.

Components of FoodborneHazards

Foodborne hazards can be classifiedinto pathogenic organisms, intrinsiccomponents and chemicals. The primarycategories of foodborne pathogenicorganisms are bacteria, viruses and

parasites. Problem pathogens that havebeen featured in the news in recent yearsinclude Escherichia coli (E. coli)O157:H7 in meat and apple juice,Salmonella in eggs and on vegetables,Cyclospora on fruit, Cryptosporidium indrinking water and hepatitis A virus infrozen strawberries. Numerous methodshave been developed and are used toreduce risks posed by pathogenicmicroorganisms including pasteuriza-tion, cooking, addition of preservativesand proper storage conditions.

Intrinsic food components includenutritional factors and thousands ofcontaminant compounds naturallypresent in foods. The intrinsic compo-nent hazards in the food supply associ-ated with nutritional factors can be eitherdeficiencies or excesses. Pellagra,scurvy, goiter, rickets and beriberi areexamples of the former, and toxicityfrom excessive fat-soluble vitamins andminerals illustrates the latter. On theother hand, natural contaminants includethose occurring in foods of plant origin,such as the oxalates in spinach and theglycoalkaloids in potatoes. Eating anutritious diet including mixed andvaried components can minimize most ofthese problems.

Hazardous chemicals in foodsinclude naturally occurring toxicants,agro-industrial contaminants and foodadditives. The naturally occurringtoxicants pose the greatest risk, and foodadditives the least. Naturally occurringtoxicants are chemicals from the naturalenvironment that occur in foods andanimal feeds, including mycotoxins andalgal metabolites, aquatic biotoxins,phytoalexins, intrinsic components ofplants, bacterial toxins, cyanobacterialtoxins and food decomposition compo-nents. Food additives pose relativelylittle risk because of intensive testingrequired by public health agencies beforeapproval for food or animal feed use.Food additive categories in the UnitedStates are classified as direct, indirect,generally recognized as safe (GRAS)substances, pesticide residues and animaldrug residues. Major efforts are under

way to identify the risks posed by thesecompounds, develop cost-effectivemeasures to remove the risk and provideimportant information to consumers onthe role they can play in promoting foodsafety.

Risk AssessmentRisks associated with food hazards

and chemical exposure, although notcommon, make the public more aware offoodborne hazards in their daily lives.

Once a specified hazard has beenidentified as causing a particular healtheffect, a risk assessment is conducted.The goal of the risk assessment is toestimate the risk to humans caused bythe potential hazard. A risk assessment isconducted following three basic steps:hazard evaluation, human exposureevaluation and risk determination orestimation. Once these have beendetermined, a risk management strategyis developed to reduce the risk to thelowest practical level, while trying tomaintain an adequate, wholesome foodsupply.

Using aflatoxin contamination inagricultural commodities as an example,the initial step collects the availableinformation about the level and extent ofthe contamination as well as the toxicitypotential. Since the aflatoxin dose willhave an effect on the risk, nature andseverity of toxicity, this step alsoincludes a dose-response evaluation. Foreach determined form of toxicity causedby aflatoxin, the dose-response evalua-tion will help establish the quantitativerelationship between dose and risk oftoxicity in the range of doses that havebeen or might be experienced byconsumers. The assembled data arecritically evaluated to determine theforms of toxicity that may be caused byaflatoxin and to determine how vulner-able human beings may be to its toxiceffects under certain conditions.

The second step, human exposureevaluation, identifies the susceptiblecommodity or product and contamina-tion levels, the target population, thedose of aflatoxin received by individuals

The Concept of Food SafetyDouglas L. Park and Carlos E. Ayala

F

Douglas L. Park, former Professor and Head andnow with the U.S. Food and Drug Administra-tion, and Carlos E. Ayala, Postdoctoral ResearchAssociate, Department of Food Science, LSUAgricultural Center, Baton Rouge, La.


consuming the productsand the duration of expo-sure. Since not all individu-als in the population areexposed to the same doses,the dose ranges or numberof people exposed to eachof several different dosesneed to be determined.

The final step is therisk determination orestimation, which uses thetoxicological and exposureinformation to estimate thelikelihood that an adversehealth effect will occur inthe population. Despite itslimitations, risk assessmentis the best approach foraddressing safety, healthand environmental risks. Itanalyzes and evaluateslimited information, whileeliminating the guessworkin decision-making, andidentifies priority areas forfurther research.

Food Safety ProgramsFood safety programs are designed

to limit exposure to foodborne risks.Where feasible, prevention is the bestpolicy. For illustrative purposes, risksassociated with aflatoxins will be used todemonstrate how effective food safetyprograms can reduce human exposure tothose naturally occurring toxicants.Cottonseed, corn, peanuts and tree nutsare the commodities most adverselyaffected by aflatoxin contamination. Pre-harvest invasion of the toxin-producingorganism Aspergillus sp. and its subse-quent production of the toxin areunavoidable. Disallowing total availabil-ity or sale of products with potentialcontamination is not practical, particu-larly when the products are diet staplesor have high nutritional value. Ifcontamination occurs, the hazardassociated with the toxin must beremoved if the product is intended forhuman or animal consumption.

Before an effective food safetymonitoring program can be set up, it isnecessary to understand how theproducts become toxic and to have theanalytical tool to identify high-riskproducts. An optimum food safetymonitoring program for aflatoxins hasthree basic components: (1) monitoringagricultural commodities for aflatoxinsbefore or during harvest, (2) establishingregulatory limits to exposure and (3)

screening in commercial channels toidentify and separate toxic commodities.

When regulations for aflatoxin werefirst established by the Food and DrugAdministration (FDA), the toxicologicalknowledge available at that timeconfirmed an adverse health effect onlivestock and a potential health risk forhumans. A human food and animal feedsafety program has been established tominimize human exposure to aflatoxinand its metabolites, protect animal healthand provide an adequate food supply.This led to regulatory levels that varyaccording to the intended end-use of theproduct.

This Louisiana Agriculture issueprovides a snapshot of research effortsunder way in the LSU AgriculturalCenter to minimize risks associated withthe consumption of foods. These includealternative food packaging to control thegrowth of pathogenic bacteria, thepasteurization of raw in-shell oysters toreduce risks posed by Vibrio species, theimplementation of a rapid microbialdetection laboratory to support enhancedfood quality efforts and the mandatedhazard analysis and critical controlpoints (HACCP) program, the develop-ment of a bar code system for continuousmonitoring of pathogenic bacteria inmuscle foods and the evaluation of newtechniques to reduce aflatoxin levels incorn.

Dr. Douglas L. Park headed a team of LSU AgCenter scientists that helped develop a pasteurizationprocess to make raw, in-shell Gulf Coast oysters safe to eat. (See page 2.)

Risk ManagementRisk management is the process of

using information obtained in the riskassessment procedure and weighingpolicy alternatives to select the mostappropriate regulatory action. Unlikerisk assessment, risk management is ahighly subjective scheme, because itinvolves preferences and attitudes notpart of the risk assessment process. Also,a high degree of public acceptance isessential for the success of risk manage-ment decisions.

In principle, risk managementinvolves the identification and appraisalof available management alternatives,the selection of the best alternatives, andthe implementation, monitoring andenforcement of the selected alternatives.Some practical risk managementalternatives contributing to food safetyinclude:

Establishment of regulatory limits.Monitoring of food productsbefore and during harvest andprocessing.Screening and testing of productsin commercial channels.Developing decontaminationprocedures.Diverting products to less riskyuses.

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n December 1996, the U.S. Foodand Drug Administration (FDA) issued arequirement that all seafood must beprocessed using Hazard Analysis andCritical Control Point (HACCP) prin-ciples. The intent of the requirement is toincrease food safety and consumerconfidence.

The seven principles of HACCP are:1. Conduct a hazard analysis and

identify preventive measures.2. Identify critical control points

(CCP).3. Establish critical limits.4. Monitor each CCP.5. Establish corrective actions.6. Establish a record-keeping

system.7. Establish verification procedures.

Although the use of HACCPprinciples in food processing has becomemore important in recent years, theconcept, as applied to food manufactur-ing, has been around for more than 35years. The Pillsbury Company initiallyused the principles to manufacture foodfor the U.S. space program in the early1960s. By 1974, low-acid canned foodmanufacturers were HACCP-regulated toprotect consumers against botulism.

Over the years, HACCP has proved to bean effective, systematic way to ensuresafe food to consumers. The U.S.Department of Agriculture requiresHACCP in the processing of red meatsand poultry. Today, HACCP is theprincipal food safety tool used byregulatory agencies.

HACCP is effective because itrequires seafood processors to identifyfood safety hazards and then to initiateactions that prevent the hazard fromaffecting the seafood. Using HACCPprinciples allows for a preventive ratherthan reactive food safety system. Forexample, processors of cooked, ready-to-eat seafoods such as crabmeat, crawfishmeat and shrimp know that bacteriaassociated with the live seafood must bedestroyed before the product can beprovided to consumers. Using HACCPprinciples, processors determine thatachieving a specific minimum tempera-ture at the cooking step will destroy thebacteria that may cause illness. UsingHACCP in food processing is not a zerorisk strategy, but when performedcorrectly, seafood processors andconsumers can be confident that thehazards have been eliminated.

A key element in HACCP imple-mentation is training. So important istraining that the seafood regulationrequires that certain HACCP functionsbe performed only by “an individualwho has successfully completed trainingin the application of HACCP principles.”The regulation further states that thistraining must be “at least equivalent to

that received under standardizedcurriculum recognized as adequate” bythe FDA.

HACCP represents a major changefor seafood processors in many ways.First, they must keep records fordesignated processing steps to ensurecontrol over identified hazards. Inaddition, these records are used as part ofthe inspection process by regulatoryagencies. Second, processors must havea good understanding of potentialhazards associated with seafoods and thescience involved in controlling thosehazards.

Generally, hazards fall into threecategories: biological, chemical andphysical. Consequently, processors mustunderstand such concepts as the time andtemperature relationships needed todestroy or minimize the effects ofbiological (microbial) hazards, thenatural and man-made toxins andchemicals that can contaminate foodsand ways to prevent foreign objects fromcontaminating foods.

In 1994, a National SeafoodHACCP Alliance was formed in antici-pation of a HACCP training requirementas part of future regulations. The initialgroup was composed of representativesfrom governmental agencies, industryand university programs, including anLSU Agricultural Center representative.The overall goal was to increase thesafety of domestically processed andimported seafoods consumed in theUnited States through a focused HACCPtraining and education program.

Trainingprogram

helps keepseafood

safeMichael W. Moody

Michael W. Moody, Specialist, Department ofFood Science, LSU Agricultural Center, BatonRouge, La.

Using HACCP principles, seafood processors document the safety of products.Sometimes this includes handling and storage practices at harvest.

Trainingprogram

helps keepseafood

safe



The Alliance estimated that therewere more than 5,000 domestic-licensed seafood processing firms.There are nearly 500 individual seafoodprocessing permits in Louisiana alone.In addition, the Alliance estimated thatnearly 3,000 state and federal seafoodinspectors and other individuals wouldseek training.

Working in concert with FDA, theAlliance developed and published acore curriculum, which has become thestandard referred to in the regulation. Amanual, now in its second edition, ismore than 200 pages long and isavailable in both English and Spanish.The Alliance also developed a protocolfor teaching the course. The course isthree days long, and all successfulstudents receive a Certificate ofCompletion from the Association ofFood and Drug Officials (AFDO). Thiscertificate shows proof to regulatoryagencies that an individual has met thetraining requirement.

In October 1996, the LSUAgCenter offered the first seafoodHACCP class to a group of 28 proces-sors. Since that time, the AgCenter hasprovided 24 classes statewide, with 921students successfully participating inthe training. Representatives from the

FDA and the Louisiana Office of PublicHealth participated in teaching everycourse in Louisiana.

Nationally, there have been 364basic courses offered by other universi-ties and consulting groups to 9,701students. Internationally, the numbersare 63 basic courses and 1,170 students.

As a result of this effort, mostLouisiana processors have a HACCP-trained employee responsible forwriting and implementing a HACCPplan. However, because of turnover ofpersonnel in processing facilities andthe start-up of new facilities, the

AgCenter will continue training but ona reduced scale. An individual needs totake the course only once.

Because of the popularity of theHACCP training, seafood processors,including those from Louisiana, haverequested a complementary coursedealing specifically with plant sanita-tion. The Alliance has undertaken thischallenge and has prepared a one-daycourse titled Sanitation StandardOperating Procedures (SSOP) training.This course will address issues associ-ated with cleaning and sanitizing of thefacility, employee sanitation practicesand plant design.

As in the basic HACCP trainingcourse, a manual has been developedalong with a course protocol. Successfulparticipants will receive certificatesfrom AFDO. There is no requirement inthe HACCP regulation that seafoodprocessors receive sanitation training,but many seafood processors haveexpressed a desire for the course. TheLSU AgCenter will offer the coursebeginning in the summer of 2000.

The Louisiana seafood processingindustry, working hand-in-hand withthe LSU AgCenter, is meeting theHACCP challenge.

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HACCP affects the entire processing facility. Employees must be aware of their responsibilities to produce a clean product and to userecommended sanitary practices. A HACCP-trained individual must document daily sanitation practices.

HACCP requires that seafood processorscontrol biological, chemical and physicalhazards. Processors must be sure thatproper cooking times and temperatureshave been used to eliminate pathogenicbacteria, which are a biological hazard.



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T hroughout the various phases ofthe food production and processingsystem, opportunities for contaminationexist. Reliable laboratory and fieldmethods are necessary to rapidly detectand trace the source of contamination.To enhance early detection and continu-ous monitoring of foodborne diseasenationwide, new and improved diagnos-tic tools are needed. They should providerapid, cost-effective testing for patho-gens in food animals, agriculture andaquaculture products, animal feeds andprocessed food products.

One new tool is called the FoodSentinel System (FSS). Unlike othersystems that involve the collection of asample at a given time and place andsubsequent sample preparation andanalysis, the Food Sentinel Systemremains with the product and performs acontinuous tracking for product safety.This helps alert food processors, dis-

tributors, public health officials andconsumers of the presence of pathogenicbacteria of human health concern in fish,poultry, meat and some liquid products.

The Food Sentinel System is basedon a solid-phase immunobead assay (S-PIA) and antibody sandwich principlesmodified to allow the continuous flowand exposure of product juices andcontaminating microorganisms. It is animmunochemical method linked to auniquely designed commercial universalproduct code (UPC) bar system.

As contaminants such as Salmonellasp., Escherichia coli 0157:H7, Listeriamonocytogenes flow through the FSS,they bind to colored immunobeads(specific-pathogen antibodies bound toblack latex microspheres) that, in turn,migrate to be captured by a secondspecific antibody. This antibody isattached to a membrane forming part ofthe bar code system. The presence of the

contaminatingbacteria isevident by theformation of alocalized darkbar on themembrane as aresult of theimmunobead-antigen complexagglutinating onthe captureantibodylocation.

The darkbar modifies theappearance ofthe overlying barcodes in twoways. Thepurveyor’s barcode is renderedunreadable byany scanner,while the lower

FSS bar code indicating contaminationbecomes readable from the added bar.The membranes are designed to allowentry of pathogenic bacteria, prevententrance of interfering substances andmaintain the immunobead-bacteriacomplex inside the system.

Bar code scanning can be done withhand-held devices or be automated aspart of packaging, transportation, storageand retail operations. Scanners can beprogrammed to read the type of contami-nation, product and the date and locationof the reading. In the absence of scan-ning devices, the consumer at home canobserve the appearance of a new symbolon the bar code signaling contamination.

The Food Sentinel System isinexpensive. Its usefulness in the foodindustry is greater than conventionalmicrobial testing because it continuouslymonitors microbial presence fromslaughter to the processing plant to theconsumer. Product and economic lossesare, therefore, reduced. Its universalpresence is better than conventionalmonitoring by random sampling.

Research at the LSU AgriculturalCenter’s Department of Food Sciencewill help bring the Food Sentinel Systeminto actual use, which is expected in thenext few years. Contributions of LSUAgCenter research include the following:

Concept and adaptation of S-PIAto the optical scanning bar codesystem.Evaluation and selection ofsystem solutions.Selection of membranes, latexbeads, structural films andsurfaces, absorbent pads andfilters.Evaluation and optimization ofthe migration process for optimalflow.Simplification and reduction ofsystem dimensions.Testing under natural packagingconditions.Testing under diverse physicalconditions.Testing additional structuralmaterials.

Carlos E. Ayala, Postdoctoral ResearchAssociate, and Douglas L. Park, formerProfessor and Head, Department of FoodScience, LSU Agricultural Center, Baton Rouge,La., and now with U.S. Food and DrugAdministration.

AcknowledgmentThe Food Sentinel System is a registeredtrademark of SIRA Technologies, whichhelped with the funding of this research.

The Food Sentinel System uses a bar code to help detect pathogens.This bar code travels with the product from processing to retail, and acolored bar appears if there is contaminating bacteria present.

Carlos E. Ayala and Douglas L. Park

New bar code will helpmonitor food safety

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iguatera fish poisoning is a typeof food poisoning caused by ingestion ofcertain tropical and subtropical marinefish that harbor natural toxins originatingfrom microscopic algae (dinoflagellates).The illness is widespread in the tropicalCaribbean, subtropical North Atlanticand the Pacific regions. More than 400

different fish species, including amber-jack, moray eel, barracuda, Spanishmackerel, triggerfish, snapper, parrotfish, surgeon fish and grouper have beenassociated with ciguatera outbreaks.

Ciguatera exhibits itself in a varietyof ways with many symptoms rangingfrom gastrointestinal to neurological tocardiovascular disorders. The symptomslast from an initial duration of 14 to 21days, to months or even years. The onsetof symptoms usually occurs within 3 to 5hours after eating a toxic fish. Generalsymptoms are flu-like. Prolonged casesmay also exhibit depression and phobiadevelopment. Low blood pressure,reduced blood volume, coma or deathmay occur. Susceptibility to the toxinsand severity of the symptoms varygreatly among individuals because of thepossible presence of several differenttoxins. Immunity does not develop.Evidence suggests that individuals who

have been previously exposed are moresusceptible and react to lower levels ofthe toxin. Additionally, the severity ofthe symptoms increases with subsequentingestions of ciguatoxic fish.

The major source of the toxins is agroup of dinoflagellates, which areplanktonic unicellular aquatic microor-

ganisms. Most, likeplants, containchlorophyll forphotosynthesis andare primary produc-ers of energy in theocean food chain.Dinoflagellates showtraits of both animalsand plants. Zoolo-gists classify them asprotozoans andbotanists as algae.They can sometimesreproduce inenormous numbers,called a bloom.Certain speciesproduce a strongnerve toxin and areresponsible for the

blooms called red tides that have killedlarge numbers of fish and have contami-nated clams and mussels, which maythen be lethal to humans who eat them.

Ciguatera toxins are odorless,tasteless and difficult to detect by anysimple chemical test. They are lipid-soluble, heat-resistant and acid-stable.This means the toxins cannot be elimi-nated by boiling, salting, drying,freezing, marinating or cooking the fish.

Detecting the toxinThere has been increasing interest in

development of a simple, rapid andinexpensive way to detect ciguatoxin andrelated toxins. Since the early 1990s,HawaiiChemtect International (Pasa-dena, California), in association withLSU Agricultural Center researchers, hasbeen working on development of acommercial kit named Ciguatect, whichinvolves an innovative rapid solid-phase

immunobead assay. Before the develop-ment of the Ciguatect kit, there was notest available which could be conductedoutside of a laboratory. This test willallow fishers, processors and individualsat various stages in the food chain todetect the presence of ciguatoxins.

The Ciguatect kit is a qualitativemethod for detecting the presence ofspecific antigens, such as toxins, on aspecial membrane attached to a plasticstrip for support. The suspected sample(tissue or its extract containing the toxin)is immobilized on the membrane andexposed to an immunobead solution.This solution is prepared by combiningan antibody specific to the toxin withmicroscopic colored latex beads. Thisprocess allows the antibody to be boundto the beads’ surface. The resultingimmunobeads are then capable ofbinding to the toxin whenever present onthe membrane. In running the test, thespecific immunobeads get bound to theimmobilized antigen within a fewminutes, resulting in a color change onthe membrane that indicates the presenceof the antigen. The assay can be consid-ered semi-quantitative, since the inten-sity of the color reflects the antigenmagnitude in the sample.

Test procedureThe Ciguatect test kit procedure for

ciguatera fish poisoning toxins in wholefish is simple and rapid. The usernormally makes a deep incision about 1inch behind the head of the sample fishand inserts the membrane end of the teststrip. The strip is placed on a flat surfaceuntil the membrane is dry (about 5minutes). The membrane end of the teststrip is immersed in methanol solution

Douglas L. Park, former Professor and Head andnow with the U.S. Food and Drug Administra-tion, and Carlos E. Ayala, Postdoctoral ResearchAssociate, Department of Food Science, LSUAgricultural Center, Baton Rouge, La.

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After a 10-minute incubation in immunobead solution, bluecoloration of the membrane containing a sample denotes thepresence of a specific marine biotoxin.

Scientists develop rapid,user-friendly test kit

for marine toxinsDouglas L. Park and Carlos E. Ayala

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and then allowed to dry for about 5minutes. This step helps the toxinmigrate from the tissue to the membranestructure where it is immobilized. Themembrane end of the test strip isimmersed in the immunobead solutionand left undisturbed for 10 minutes. Nocolor on the membrane is indicative ofnegative toxicity, and it is given a scoreof zero. The presence of color on themembrane denotes the presence ofciguatoxin in the fish. A faint colorindicates borderline toxicity. Theintensity of color is compared to a set ofpositive results ranging from 1 to 5. Theaverage value for the scores fromduplicate or triplicate sample strips iscalculated and recorded for the corre-sponding laboratory report.

ApplicationsThe Ciguatect kit can be used for the

detection of toxins associated withciguatera fish poisoning and in rapidscreening programs of toxic fish andshellfish in harvesting areas and themarketplace. In a kit configuration, thistype of marine toxin detection assay canbe used routinely for high-volumescreening of suspect toxic fish on boardships, in rudimentary dockside laborato-ries and at aquaculture facilities, as well

as in regulatory agency laboratories.Ciguatect can be adapted to test

mussel samples for the presence of themain toxin responsible for diarrheicshellfish poisoning in some parts of theworld. In addition to helping to monitorshellfish beds for shellfish poisoningtoxins, the kit can be applied in shellfishdepuration operations for elimination ofthe toxins, and to screen for toxicmussels, scallops and oysters in themarketplace.

Technologies such as this are usefulto governments around the worldconcerned with rapid, inexpensivecommercial testing procedures toidentify unsafe fishing locations. Theyalso help in random testing of suspectcommercial catches to ensure the safestseafood products for the public.

This test kit is not yet availablecommercially. The LSU AgCentercontinues to be involved in itsdevelopment.

The square membrane attached to the end of the supportingplastic strip holds the test sample, negative control or positivecontrol, before immersion in blue immunobead solution specific fora marine biotoxin responsible for fish or shellfish poisoning.

AcknowledgmentCiguatect is a registered trademark ofHawaiiChemtect International, which helpedto fund this research.

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laIntroducing ‘Earl’

Scientistsdevelop newrice variety

Scientists at the LSU AgCenterhave developed a new medium-grainrice variety, named Earl, that offersimproved yield and disease resistance.

Earl has “inherently very goodyield potential,” according to Dr. SteveLinscombe, rice breeder at the LSUAgCenter’s Rice Research Station atCrowley.

“This new variety addresses spe-cific issues,” Linscombe said. “It hasbetter resistance to blast disease andis a little higher yielding than Bengal, avariety we introduced in 1992.”

Bengal is the most widely grownmedium-grain rice in Louisiana – withabout 90 percent of the 38,000 to40,000 acres of medium-grain rice inLouisiana – and it also dominates theArkansas medium-grain productionin about the same proportion, ac-cording to Dr. Bill Brown, associatevice chancellor of the LSU AgCenter.

Rice farmers produced nearly$276 million worth of rice at farmprices in 1998, while value-added pro-cessing supplied another $82 millionto the Louisiana economy in 1998,according to the LSU AgCenter’s Loui-siana Summary of Agriculture andNatural Resources.

“The variety is named in memoryof Earl Sonnier, who was the directorof foundation seed production at theRice Research Station for many yearsas well as a recognized authority onrice seed production internationally,”Linscombe said.

The Rice Research Station hasproduced 250 hundredweight of Earlas foundation seed for 2000, said Dr.Joe Musick, the station’s resident di-rector. The seed has been allocatedto growers who will produce seed forthe 2001 crop. Rick Bogren


eef consumers are provided with various kinds ofinformation on the fresh beef sold in grocery stores. Retail beefpackages include all or some of the following: U.S. Depart-ment of Agriculture (USDA) Quality Grade, species of meat,standardized and common cut name, brand or store label, priceper unit, weight, total package costs, refrigeration and cookingsuggestions, packaging date and limited nutrient information.Shoppers use this information and visual observation to choosemeats.

Restaurant patrons know much less about the beef servedthem. They must rely on the reputation of the restaurant andprevious meals consumed in particular restaurants.

With limited exceptions, information on whether the beefwas produced in the United States or imported has beenunavailable to consumers. While U.S. Customs’ regulationsrequire all imported beef be labeled by country-of-origin onthe bulk shipping container, the label is not required toaccompany the beef to the next buyer unless imported in retailready packages. Hence, all imported fresh or frozen beefessentially becomes U.S. beef when repackaged.

Louisiana has become the first state to mandate thislabeling, however, when the 1999 Louisiana Legislatureenacted legislation requiring all fresh meats sold in grocerystores beginning January 1, 2000, to indicate “American,”“Imported” or “Blended,” the latter consisting of a mix of U.S.and imported meat. The law exempted all food service use,including restaurants.

U.S. consumers may be interested in the country-of-originof fresh or frozen beef for these reasons:

Imported beef might differ in quality from U.S.-produced beef.Countries licensed to export beef to the United Statesdiffer in the degree of government control of use ofspecific chemicals in the production of the animals andtheir feeds.Consumers may be concerned with the stringency ofregulation of slaughter and processing operations in thelicensed countries.Some consumers prefer to purchase U.S. products overimported products.

The USDA states that all slaughter houses licensed tohandle beef to be exported to the United States must meet thesame requirements as those imposed on U.S. slaughter orprocessing plants. It also claims that all imported beef israndomly inspected at port of entry for residues or otheradulterants. Now 32 countries, including Canada, Japan andMexico, require all fresh beef to be labeled by country-of-origin at the retail meat counter.

To determine the preferences of Louisiana beef consumersconcerning country-of-origin labels for fresh or frozen beef ingrocery stores and restaurants, we sent a survey to 2,000randomly selected households in eight parishes in the summer

Consumers approve mandatorycountry-of-origin labeling

of fresh or frozen beefLouisiana first to require information

Alvin Schupp and Jeffrey Gillespieof 1999. About 18 percent of the households responded to thesurvey. The sample was slightly biased toward higher income,more highly educated, white and older respondents, which istypical of the response rate from unsolicited mail surveys usingbulk mail rates.

Respondents overwhelmingly considered U.S. beefsuperior to imported beef (86 percent rated U.S. beef superiorto 14 percent rating U.S. and imported beef as equal). Theprimary reason for the superiority of U.S. beef was its higherquality. The remaining reasons involved consumer concernsabout safety.

When asked whether they favored compulsory country-of-origin labeling of fresh or frozen beef, 93 percent favored thelabel in grocery stores and 88 percent in restaurants. Respon-dents who were more likely to favor the label for grocerystores were those who (1) favor domestic durable goods toimported durable goods, (2) rate U.S. beef superior to importedbeef, (3) are black or (4) are from rural areas. Respondentswho were less likely to be in favor of the label were (1) older,(2) single, (3) male, (4) engaged in farming or (4) had childrenin the household.

Respondents who were more likely to favor the label forrestaurants were those who (1) favor domestic goods toimported durable goods, (2) rate U.S. beef superior to importedbeef and (3) generally read nutrition labels on food items.Males were less likely to favor the label for restaurants.

Preference for the labels did not differ with income,education level, whether there was a homemaker in thehousehold, and whether the respondent was retired. In mostissues related to food consumption, these variables are impor-tant in explaining the household’s choice.

The rate of approval of mandatory country-of-originlabeling of fresh or frozen beef in grocery stores and restau-rants (averaging 91 percent) estimated from this study exceedsthat of a recent national survey (76 percent).

The lower approval of mandatory country-of-origin labelsfor restaurant beef likely reflects the fact that consumers aremore accustomed to having less information on the meatsconsumed in restaurants than is available on packaged meats ingrocery stores.

The finding that households with single heads or house-holds with children tend to be less supportive of the country-of-origin label needs to be examined by the domestic beefindustry.

At this writing, implementation of the law is awaitingregulations that must be developed by the state Department ofAgriculture and Forestry.

Alvin Schupp, Martin D. Woodin Professor, and Jeffrey Gillespie, AssistantProfessor, Department of Agricultural Economics and Agribusiness, LSUAgricultural Center, Baton Rouge, La.

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Ozone:Ozone:Ozone:

zone is a substance best known intwo divergent ways. It is both benefi-cial—as in the ozone layer protecting theEarth from the sun’s harmful ultravioletrays—or detrimental when ground-levelconcentrations become excessive,particularly on hot, humid days.

Because ozone is one of the stron-gest oxidants known, it can be used toirreversibly degrade harmful microbesand toxic compounds. Ozone normallyexists as a gas, which is more soluble incold water than warm water. Ozonecontains three atoms of oxygen whereas,in the air we breathe, oxygen containsonly two atoms. Ozone is more reactivebecause of the extra oxygen atom andcan donate an oxygen atom to othersubstances to oxidize them, leaving theremaining two oxygen atoms to formregular oxygen found in air. This fact isimportant because there is no residue leftfrom the ozone itself.

Ozone can be produced commer-cially either through electrolysis orcorona discharge. In corona discharge,air or pure oxygen is fed into a unit thatconverts the oxygen to ozone using highvoltage. This procedure has disadvan-tages that include high capital andoperating costs, generation of toxicmolecules containing both nitrogen andoxygen if air is used, possible toxiccontamination by the electrode materialand, most important, low ozone concen-trations of 2.5 to 7.5 weight percent.

The second method involves the useof water in an electrolytic cell. Oxygenin the water is converted to ozone bypassage through positively charged andnegatively charged surfaces. Concentra-tions of ozone in this method can exceed20 weight percent. Municipal water canbe used, and the reactants and products

Joan M. King, Assistant Professor, Department ofFood Science, and Terry Walker, AssistantProfessor, Department of Biological andAgricultural Engineering, LSU AgriculturalCenter, Baton Rouge, La.

Joan M. King and Terry Walker

Dr. Joan King, left, and Dr. Terry Walker are doing research on ozonation of food productsas an alternative to other methods of eliminating pathogens. They are testing this ozonationprocessing unit as a way to remove off flavors from catfish.

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New Weaponfor FightingFood HazardsOzone:


Ozone:Ozone:Ozone:

Ozone:Ozone:Ozone:Ozone:

Ozone (O3)

Pathogens Oxygen (O2)

TreatmentTank

H2

H20 OzoneGenerator

Mix

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Col

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Diffuser

Gas

ThermalDestruction

02

are safe. Only water and oxygen are left.This process is less costly than thecorona discharge process because it usesless electricity and no special gases mustbe purchased. A commercial process forproducing ozone with an electrolytic cellhas been patented by Lynntech Inc. ofCollege Station, Texas.

Although ozone has been producedartificially since the beginning of the20th century and used in Europe forseveral decades, the Food and DrugAdministration only recently approved(1997) ozonation for use in the U.S. foodprocessing industry.

Ozone is becoming a widely usedreplacement for chlorine-based chemi-cals for water quality and for sanitationin food processing, especially in themeat industry. Studies have shown thatozone is a viable alternative to chlorinefor bactericidal effects. For example,poultry carcasses chilled with watercontaining 3.0 to 4.5 parts per millionozone scored lower in microbial countsthan those chilled in non-ozonated water.There was no significant color change oroff flavor in the ozone-treated productcompared with controls.

Recently, ozone has been used inaquaculture for control of bacteria, todisinfect and for water quality. Ozonegenerators are used in the United States,Russia and Japan to make ozonatedprocessing water for cleaning fish.Ozonation has shown potential gains in

catfish shelf life, ice quality productionand more efficient operation of waterchillers in fish processing plants.

At the LSU Agricultural Center,several studies have been initiated usingozonation. One involves degradation ofoff-flavor compounds in catfish fillets.Another is the decontamination ofaflatoxin in corn grain samples. To helpwith these two research projects, anozonation processing unit is being builtin the Department of Biological andAgricultural Engineering in a jointproject with the Department of FoodScience. Figure 1 shows how this unitworks. It involves the use of water in anelectrolytic cell. A series of tubes andvalves routes the generated ozone to thefood product and to ozone detectors for

determining inlet and effluent ozoneconcentrations. For catfish fillets, thefood will be in the treatment tank on aseries of trays. Corn contaminated withaflatoxin will be ozonated in bins.

The unit built for contacting thefood product such as catfish fillets andcontaminated grains will be capable oftreating the products with either gaseousor dissolved ozone. The materials usedfor construction must be resistant tohighly corrosive ozone and are limitedprimarily to silica-glass, 316 stainlesssteel and Teflon. All ozone streams fromthe system will be collected in a thermaldestruction unit containing a manganesedioxide catalyst that converts all residualozone back to oxygen before beingemitted to the atmosphere.

Ozonation Processing Unit

Ozone contains three atoms of oxygen unlike the oxygen in the air we breathe, whichcontains two. Ozone is highly reactive and can donate an oxygen atom to other substances,such as food pathogens, and oxidize them. This leaves the remaining two atoms to formoxygen, thus emitting no harmful residue.

Figure 1. This is a diagram of the ozonation processing unit being tested at the LSU AgCenter. Hydrogen (H2) and water (H2O) go into theozone generator which then sends the ozone through a mixing column of water to the treatment tank, where the food is placed. Any ozoneleft over from the ozonation of the food product will go through a thermal destruction unit and be emitted as oxygen.

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14 Louisiana Agriculture, Spring 200014 Louisiana Agriculture, Spring 2000


heese is one of the most ancientforms of manufactured food. It is theproduct of enzymatic action and lacticfermentation of milk using variousbacterial cultures. These enzymaticactions and fermentations lead to thecoagulation of milk and production oftypical cheese characteristics.

Fermented milk products originatedin the Near East and then spread tosouthern and eastern Europe. Nomadictribes who carried milk in storagepouches made from the stomachsof cows, sheep, camels or goatsaccidentally developed the earliestforms of cheese. Under warmstorage conditions, the milkcoagulated or clabbered because of theaction of proteolytic enzymes naturallypresent in the storage containers and theproduction of acid end products by lacticbacteria. Fortunately, the predominantbacteria were lactic types (acid produc-ers) and, therefore, helped to preservethe product by suppressing spoilage andpathogenic bacteria. People evidentlyenjoyed the refreshing, tart taste of thisdiscovery and began to handle milk sothat this preserving action would beencouraged.

Milk and curdled milk products arementioned throughout history datingback as far as 4000 BC: “He asked forwater, and she gave him milk; in a bowlfit for nobles she brought him curdledmilk” (Old Testament, Judges 5:25).There is also remarkable pictorialevidence that the custom of keeping milkin containers for later consumption wasalready a craft systematically practicedby the Sumerians around 2900 BC.Through scientific principles andadvances in manufacturing technology,these early products have developed intoa highly diversified group of foodspopular throughout the world.

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Jackin N. Nanua, Postdoctoral Researcher, andJohn U. McGregor, Associate Professor,Department of Dairy Science, LSU AgriculturalCenter, Baton Rouge, La.

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The FDA recommends that pregnantwomen and immune-compromised peopleavoid consumption of soft cheeses such asCamembert, Brie, Roquefort, feta andMexican-style cheeses because of the risk oflisteriosis.

domestic soft-ripened, French-stylecheese in the retail market. Cheesesamples—three imported French Brievarieties, one German Camembertvariety and one U.S. Camembert—werecollected from three supermarketslocated in the greater Baton Rouge area.Samples were analyzed in the DairyScience Department. The cheeses wereaseptically sliced to obtain surface,intermediate and center samples.

Analyses were performed immedi-ately. Age of the cheese could notbe determined, but they werewithin the “sell by” date. Thesampling was replicated threetimes.

The pH and proteolysis decreasedfrom the surface to the center. This couldbe attributed to the activity of theripening molds. Molds produce proteasesand other enzymes that break downproteins leading to the formation ofamino acids, peptides and ammonia.They also degrade lactic acid, milk fatand produce carbon dioxide. Proteinbreakdown causes an increase in solublecitrate and short-chain peptides. The neteffect is an increase of pH. The averagemoisture content was 43 percent for Brieand 48 percent for Camembert. The highpH and moisture contents observed inthese cheeses could encourage thegrowth of microorganisms includingpathogens. Many common pathogensgrow within a pH range of 4.5 to 10.Surface mold-ripened cheeses with a pHof about 6 can support the growth ofpathogens. Listeria monocytogenes,Enterobacter aerogenes and Escherichiacoli have been reported to grow inCamembert cheese. L. monocytogenesgrow at pH 5.5 to 5.3.

Plain Brie and Brie with herbs hadhigher coliform counts than U.S.Camembert and Brie with peppercorns(Table 1). In addition, Brie with herbs

Jackin N. Nanua and John U. McGregor

Safety and Soft-Ripened,French-Style Cheeses

Different varieties of cheese arecreated by varying coagulation agents,processing methods and ripening agents.Cheeses can be classified by moisturecontent as hard, semi-hard and soft.During the ripening of cheese, lactic acidbacteria use lactose to produce acid andother flavor compounds, some of whichinhibit undesirable contaminatingmicroorganisms.

Mold-ripened soft cheeses such as

Camembert and Brie are inoculated withthe mold Penicillium camemberti, whichproduce proteolytic enzymes leading toprotein hydrolysis. The amines andammonia produced during proteinhydrolysis raise the pH of the cheese tolevels that can allow growth of undesir-able microorganisms. Spices are some-times added to these cheeses, and thesecould introduce undesirable microorgan-isms into the cheese. It has been demon-strated that pathogens such as Listeriamonocytogenes can grow during theripening of Camembert cheese butdecrease during the ripening of Cheddarcheese.

Disease riskA number of disease outbreaks have

been traced to consumption of softcheese. This has raised safety concerns,especially for vulnerable consumers suchas pregnant women and immune-compromised individuals. The Food andDrug Administration (FDA) recom-mends that pregnant women avoidconsumption of soft cheeses such asCamembert, Brie, Roquefort, feta andMexican-style cheeses because of therisk of listeriosis. Stringent hygienicstandards should be maintained duringthe manufacture and subsequent han-dling of soft-ripened cheese to minimizechances of contamination.

Researchers in the LSU AgriculturalCenter’s Department of Dairy Scienceconducted a study to assess the micro-biological quality of imported and

“Cheese is probably the best of all foods,as wine is the best of all beverages.”

Patience Gray, author


Table 1. Mean Coliform Count

Brie-pep Cam-Germ Cam-USA Brie-plain Brie-herb Mean

Surface 0.69 4.53 1.46 3.13 5.47 2.95

Intermediate 0.00 0.00 0.00 1.13 3.83 1.06

Center 0.60 0.00 0.00 0.93 2.55 0.87

Brie-pep = Brie with peppercorns; Brie-plain = plain Brie; Brie-herb = Brie with herbs; Cam-Germ= Camembert from Germany; Cam-USA = Camembert from USA.

had high coliforms in the interior whileall the other cheeses had very fewcoliform counts in their interiors. Thehigher internal contamination of Briewith herbs might be caused by mixingherbs into the cheese. The herbs aremixed into the cheese interior, andpeppercorns are applied only to thesurface.

Brie and CamembertBrie had a higher incidence of

microbiological contamination thanCamembert. Brie is typically sliced intowedges in the retail shop, and

Camembert is presented as wholewheels. Contamination may haveoccurred during the cutting in thesupermarkets. Four Brie wheels werecollected from the supermarkets beforecutting into wedges and analyzed forcoliforms to determine whether contami-nation was at the cutting stage. Only onewheel had detectable coliform bacteria,confirming that cutting in the supermar-ket is probably responsible for most ofthe contamination with coliforms. No E.coli were detected in any of the cheesesamples examined. Canned Camembert,which is normally pasteurized by

dipping in hot water, had no viablemicroorganisms.

The soft-ripened cheeses examinedin this study had viable coliforms. Thisindicates conditions that could haveexposed the products to microbialcontamination. This is a cause ofconcern, especially for high-risk con-sumers such as pregnant women, theyoung, the elderly and immune-compro-mised individuals. High-risk consumersshould consume cheeses like Cheddarand mozzarella instead.

The higher coliform count on thesurface suggests post-process contamina-tion, most likely during cutting and theadding of spices for Brie. This could bereduced by using high quality spices andby following good sanitary proceduresduring the cutting step carried out atretail supermarkets.

Another means for potentiallyimproving the microbiological quality ofcheese at the retail level is to buy cheesecut and wrapped at the cheese manufac-turing plant. The sanitary proceduresused in dairy processing plants aretypically strict and carried out by highlytrained food industry professionals.

Although most refrigerated, uncooked beef is still packagedin traditional air-permeable, moisture-impermeable film on apolyfoam tray, more ground beef is being packaged at a centralfacility with different proportions of atmospheric gases (nitrogen,carbon dioxide, oxygen) to inhibit the growth of spoilage andpathogenic (disease-causing) microorganisms.

Since spoilage bacteria usually grow faster than pathogens,consumers have been able to use the spoilage indicators of odorand discoloration to determine the relative safety of refrigeratedfoods. However, several studies have indicated that pathogenicmicroorganisms may outgrow the spoilage organisms in atmo-spheres with little or no oxygen. This hazard may be greater ifelevated temperatures occur during storage or retail display.

For this experiment, ground beef patties were packaged intwo reduced oxygen types to determine the relative growth ratesand types of microorganisms during refrigerated storage anddisplay. Patties weighing 1/4 pound were formed from groundchuck and assigned to two packaging treatments: vacuum ormodified atmosphere (MAP) containing 50 percent nitrogen and50 percent carbon dioxide.

Pathogenic microorganism hazardswith reduced oxygen packaging of ground beef

Two studies look at packaging of ground beef

After 15 days of storage at 30 degrees F, the gas atmospheresin the MAP packages were exchanged for 80 percent oxygen and20 percent carbon dioxide. The patties were removed fromvacuum packaging and were overwrapped in polyvinylchloridefilm. Packages were displayed three days at 45 degrees or 60degrees F under simulated retail conditions.

Samples were taken at zero, 8, 15, 16, 17 and 18 days afterinitial packaging to determine color, microbial numbers and typesof microorganisms.

There was no difference in microbial numbers on patties inMAP or vacuum packaging for patties during the first 8 days of theinitial storage period. However, the microbiological counts onpatties stored in vacuum increased greatly from days 8 to 15. Thiswas unexpected since a storage temperature of 30 degrees Fclose to the freezing point (28 degrees F) of beef usually inhibitsmicroorganism growth, as was observed with the patties in MAP.

Microbiological growth increased upon retail display withboth temperatures. The 45 degrees F temperature is not uncom-mon for meat display cases, although 41 degrees F or below isrecommended.


Retail display of patties at the abusive temperature of 60degrees F caused rapid growth of microorganisms in both typesof packaging compared with display at 45 degrees F. The numbersof pathogenic bacterial species increased from 11 percent to 70percent in MAP and from 24 percent to 50 percent in overwrappedpackages displayed at 60 degrees F during the three days ofdisplay.

Discoloration of the bright red beef pigments to brown isoften used as an indication of the advancing spoilage of groundbeef. Patties in MAP with high levels of oxygen were darker andredder than patties stored in vacuum. Patties in MAP were redderthan patties in air-permeable packaging through the first two daysof retail display because of the higher levels of oxygen in the

Influence of display gas mixture on shelf life of ground beefin modified atmosphere packaging

packages. The lightness of patties in MAP remained fairly constantthrough three days of retail display. Display at 60 degrees Fdecreased lightness of patties in air-permeable packages anddecreased redness of patties in MAP compared with display at 45degrees F.

The implications from this research are that reduced oxygenatmospheres will alter the microbial populations, while exertingminimal influences on color during storage and retail display. Theincreased percentage of pathogenic microorganisms with retaildisplay in oxygenated conditions was increased even more withabusive temperatures during display. Processors and retailersshould be vigilant in maintaining low temperatures in display casesto safeguard their refrigerated meat products for consumers.

Modified atmosphere packaging (MAP) of fresh meat prod-ucts can improve the shelf life, reduce economic loss and improveproduct quality. The use of vacuum to remove oxygen preventsoxidative changes, but also causes meat to become a purple color,which is unappealing to consumers. Inclusion of carbon dioxidein MAP will inhibit microorganism growth and increase shelf life.

Ground beef is the major fresh beef product, accounting forabout half of the total beef consumed in the United States. Todetermine the levels of gases for optimal display shelf life ofground beef, different gas atmospheres during storage wereexchanged with different gases before retail display.

Ground beef patties were manufactured from chuck rolls bygrinding muscles through 1/2-inch and 1/8-inch plates beforeforming into 1/4-pound square shapes on a mechanical former.Patties were assigned to packaging in vacuum or one of threetypes of modified atmosphere packaging (MAP): 80 percentnitrogen and 20 percent carbon dioxide, 50 percent nitrogen and50 percent carbon dioxide or 20 percent nitrogen and 80 percentcarbon dioxide for storage in the dark at 30 degrees F.

After 15 days, the vacuum patties were removed, placedonto polyfoam trays and overwrapped with air-permeable, mois-ture-impermeable polyvinylchloride film. The atmospheres in theMAP packages were exchanged for 80 percent oxygen and 20percent carbon dioxide; 50 percent oxygen, 20 percent carbondioxide and 30 percent nitrogen; or 20 percent oxygen, 20percent carbon dioxide and 60 percent nitrogen. All packageswere displayed under simulated retail conditions of 45 degrees F.

The storage gas mixtures of nitrogen and carbon dioxide hada large influence on the growth of psychrotrophic microorganismplate counts on patties in MAP during storage and retail display.The display gases of oxygen and carbon dioxide had little influenceon microorganism growth during display. The psychrotrophicbacteria are those able to tolerate and grow in refrigeratedtemperatures. Many of the pathogenic microorganisms that causefoodborne disease are psychrotrophs. Increased levels of carbondioxide inhibited psychrotrophic microorganisms until the atmo-spheres were exchanged for oxygen and carbon dioxide on day15. Then the carbon dioxide in the gas mixtures was unable toimpede the growth stimulated by oxygen. The vacuum atmo-sphere did not inhibit bacterial growth during the storage period.

Color of fresh refrigerated meat is the main criteria used byconsumers to make their purchase decisions. The values thatindicate lightness of color were not different among patties fromthe different storage or display packaging treatments. The red-ness of patties during storage was similar between vacuum andMAP treatments. After gas exchange for oxygen mixtures, thecolor of beef patties in MAP became redder. The patties fromvacuum storage treatment that were exposed to air becameredder (bloomed) slightly, but less than the patties in oxygen. Thered color faded after 2 days of display under lighted retailconditions and was not acceptable for consumer purchase after4 days of retail display. Patties in higher levels of oxygen hadhigher yellow values than patties in lower levels of oxygen duringdisplay. Following re-packaging in air-permeable film, pattiesstored in vacuum were less blue during the dark storage and hadyellow values similar to the patties in 50 percent oxygen, 20percent carbon dioxide and 30 percent nitrogen,.

Oxygen is a concern with refrigerated packaged fresh meatbecause it causes oxidation of the lipids and rancidity to develop.In this study, lipid oxidation increased during storage in vacuumor in nitrogen/carbon dioxide gases. The lipid rancidity increasedgreatly during exposure to light during retail display and washigher with increased levels of oxygen in the display gas mixtures.

This study investigated the use of different gas mixtures onthe shelf life of ground beef patties during storage and retaildisplay. Increased levels of carbon dioxide inhibited the growthof psychrotrophic microorganisms while increased levels ofoxygen increased red color and lipid oxidation. The most desir-able gas combinations for MAP of ground beef in this studyappeared to be 50 percent nitrogen and 50 percent carbondioxide exchanged for 50 percent oxygen, 20 percent carbondioxide and 30 percent nitrogen for retail display. This MAP gassystem resulted in ground beef patties that had low microbialgrowth during storage and minimum lipid rancidity and desirablered bloomed color during display compared to other treatmentcombinations.

Chung Ping Ho, Image Global Marketing Development and ServicesCompany, Taipei, Taiwan, former graduate student; Kenneth W.McMillin, Professor, Department of Animal Science, LSU AgriculturalCenter, Baton Rouge, La.; and Nai Yun Huang, U.S. Meat ExportFederation, Taipei, Taiwan, former graduate student.


Inhibition of E. coli in Ground Beef Patties with OzoneAnother preservation technique being investigated involves

ozone, which may be equally effective in destroying pathogenicmicroorganisms with less cost and fewer product changes. Thisstudy was conducted to determine the effect of gaseous ozone onspoilage and pathogenic microorganisms in ground beef.

Ground beef was treated in two ways: (1) coarsely groundand vacuum packaged or (2) finely ground (1/8-inch) and formedinto 1/4-pound patties. The patties were packaged in modifiedatmospheres (MAP) in three ways: (1) 80 percent oxygen and 20percent carbon dioxide (O); (2) 80 percent nitrogen and 20percent carbon dioxide (N) or (3) 2.5 percent oxygen, 20 percentcarbon dioxide and 77.5 percent nitrogen ozonated with 2,500parts per million of ozone (O3).

All ground beef was stored in the dark at 36 degrees F.After 10 days, the coarse-ground, vacuum-packaged

beef was finely ground, made into 1/4-pound patties andplaced on foamed polystyrene trays overwrapped withair-permeable film, and the MAP packages for N and O3

treatments had the gaseous environments exchangedfor O.

All packages were then displayed under cool whitefluorescent light at 45 degrees F for 4 days.

Results included: The color of the ground beef patties was similar

among treatments during storage and display. Rancidity was higher in ground beef patties in

oxygen compared with the other treatments duringstorage. Upon repackaging or gas exchange, there wasmore rancidity. After 2 days of retail display, the ranciditylevel was very high, indicating that the product tastewould probably be unacceptable to consumers.

Microorganism counts were higher in coarselyground beef stored in vacuum packages and remainedhigher through the display of patties in air-permeable,overwrapped packages compared with the other packag-ing treatments. The carbon dioxide in the other packag-ing treatments was probably responsible for inhibitingthe growth of microorganisms on the beef patties.Ozone was not effective in inhibiting the general micro-bial species associated with ground beef.

The level of coliforms increased in the coarselyground beef in the vacuum package during storage, butremained stable in the other packaging treatments untildisplay. Coliforms are the species of microorganisms,including E. coli, that indicate unsanitary conditions andpotential foodborne illness hazards. The high levels ofoxygen in these packages appeared to destroy coliformorganisms during the first 2 days of retail display. Coliformcounts in ground beef patties in the oxygen and ozonetreatments decreased in the last days of storage andthroughout the display time.

Different packaging environments and treatmentswill influence the properties of ground beef duringstorage and retail display. Gas atmospheres that providelonger shelf life during storage give a purple meat colorthat is not acceptable for retail display. Packaging that

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LSU AgCenter scientists are testing the use of ozone gas to kill bacteria inpackaged ground beef. Behind Michael Michel, research associate in AnimalScience, is a gray box, which is the ozone generator.

Recent illnesses and deaths traced to foods contaminatedwith Escherichia coli (E. coli) O157:H7 have caused processors,regulatory officials and scientists to examine different techniquesto control and destroy pathogenic microorganisms. The patho-genic microorganisms in meat products may survive or growduring refrigerated storage. Foodborne illness can occur whenprecooked or raw meat products are eaten without adequateheating to destroy pathogens.

Irradiation has recently been approved to treat meat prod-ucts and kill pathogenic bacteria. Though effective, this preserva-tion method may be expensive and alter the palatability and shelf-life properties of meat products.



Consumers continue to demand more convenience withfood products, including meat. Safety is a primary concern withprecooked, ready-to-eat meat products. Meat processorsstrive to develop processed meat items to meet consumerdemand and increase meat consumption.

Many different food additives are available to enhanceflavor, inhibit microorganisms and preserve quality in meat.One such additive not in general use is sodium lactate, whichis a neutral salt of lactic acid. An advantage of this additive is thatit is perceived as “natural” or “organic” by some advocacygroups, as opposed to an artificially produced additive. Sodiumlactate has been shown to extend shelf life and enhance flavorwithout altering other product characteristics.

Few uncured, precooked pork items are available forconsumers. To test the value of sodium lactate as an additivein manufacturing precooked pork roasts, which would be anadditional meat item for the marketplace, a study was done thatcompared sodium lactate and sodium tripolyphosphate, usedalone and in combination. Sodium tripolyphosphate, a commonadditive, is used in meat products to increase juiciness andtexture.

Sodium lactate and sodium tripolyphosphate were incor-porated into boneless fresh pork leg muscles. The muscleswere netted to form 6- to 8-pound roasts cooked to 155degrees F internal temperature in a smokehouse. Roasts werechilled to 40 degrees F and sliced into 1/4-inch sections thatwere vacuum packaged. Packages were stored at 40 degrees Ffor sampling at zero, 4, 6 and 8 weeks.

Roasts containing sodium tripolyphosphate had highercooking yields (83 percent) compared with 69 percent yield ofroasts with no phosphates. The cooked roasts containingphosphates retained more moisture (70 percent) than roasts

without phosphates (67 percent). Fat and protein contentwere lower in roasts containing phosphates (3.4 percent fat,24.2 percent protein) than in roasts without phosphates (3.9percent fat, 26.4 percent protein).

Tensile strength necessary to shear the slices was higherin roasts containing phosphates. Roasts with phosphates werealso lighter, redder and bluer, and thus more appealing, thanroasts without phosphates. Sodium lactate did not changetexture, lightness and redness, but increased levels causedslightly bluer hues on slice surfaces.

Sensory scores increased for salt flavor and off-flavor anddecreased for pork flavor with increased levels of sodiumlactate. The use of phosphates decreased oxidative rancidityduring the 8 weeks of refrigerated storage but did not affectgrowth of microorganisms during refrigerated storage. Higherlevels of sodium lactate inhibited psychrotrophic microorgan-isms in the precooked pork more than lower levels of sodiumlactate through 4 weeks of storage at 40 degrees F. Thepsychrotrophic microorganisms are of food safety concernbecause they will grow and may produce toxins at refrigeratedtemperatures.

This study helped add information about use of sodiumlactate as a food additive for pre-cooked meat products. Theproper combination of additives, including sodium lactate andsodium tripolyphosphate, can improve product safety andpalatability while minimizing product changes during storage.

Dean J. Antie, Manda Fine Meats, former graduate student; KennethW. McMillin, Professor, Department of Animal Science; J. SamuelGodber, Professor, Department of Food Science, LSU AgriculturalCenter, Baton Rouge, La.; and Douglas L. Marshall, AssociateProfessor, Department of Food Science and Technology, MississippiState University, Starkville, Miss.

provides contact of oxygen with the meat surfaceblooms the ground beef to a desired red color,but the color fades and lipid oxidation occurswithin 2 to 3 days after display. Oxygen and ozoneappeared equally effective in destroying coliformsin the ground beef. Studies are continuing on theeffects of ozone on E. coli.

Brian S. Smith, former graduate student and now withCentral Soya Company, Fort Wayne, Ind.; Kenneth W.McMillin, Professor; Thomas D. Bidner, Professor,Department of Animal Science, LSU AgriculturalCenter, Baton Rouge, La.; and Arthur M. Spanier, U.S.Department of Agriculture Agricultural ResearchService, Beltsville Animal Research Center, Beltsville,Md.

Dr. Ken McMillin, professor in Animal Science, heads the research on ozonation ofmeat as a way to preserve it. The patty on the right has been treated with gaseousozone and is a slightly lighter red than the patty on the left.

Safety and Properties of Precooked Pork Roastswith Sodium Lactate and Sodium Tripolyphosphate


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The LSU AgCenter’s Northeast Research Station in Winnsboro was set up as an aflatoxin testing station in 1998 for farmers in that area tohave their corn tested. Allen Brown, former research associate, was involved in the testing.

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A flatoxin is a natural toxin pro-duced by the fungus Aspergillus flavus.Aflatoxin in corn appears when hightemperatures and drought stress occur,which favors infection of the ear by thefungus. Southern states are more likelyto have this problem than are the coolermid-western and northern Corn Beltareas. Louisiana experienced particularlysevere aflatoxin contamination duringthe 1998 growing season. This resultedin a large financial loss to Louisianafarmers who had to either destroy theircrops or sell them at a significantly

reduced price. If a viable alternative hadexisted for treating the infected grain toeliminate the aflatoxin, the farmers couldhave received a larger return for theirinvestment.

The possible contamination of foodcrops by aflatoxins and their potentialtoxicity to people and livestock havebeen known for almost 40 years.Aflatoxin is known to cause liverdamage and cancer in animals andhumans.

Worldwide, numerous studies aimedat understanding the biology of the fungi

Joan M. King, Assistant Professor, Departmentof Food Science; Terry Walker, AssistantProfessor, Department of Biological andAgricultural Engineering; Henry Njapau,Research Associate, Audubon Sugar Institute;Douglas L. Park, former Professor and Head,Department of Food Science and now with theU.S. Food and Drug Administration; andKenneth E. Damann Jr., Department of PlantPathology and Crop Physiology, LSU Agricul-tural Center, Baton Rouge, La.

Joan M. King, Terry Walker, Henry Njapau,Douglas L. Park and Kenneth E. Damann Jr.

Managing AflatoxinContamination in CornScientists Use Integrated Approach to Solution


that produce aflatoxins and the elimina-tion of the toxins have been carried out.Indeed, the understanding of eventsleading to the formation of aflatoxins infood crops and the effects on consumershas increased tremendously.

Preventing contamination is the bestmethod for managing the risk associatedwith consuming aflatoxin-contaminatedfoods. If contamination occurs, however,the hazards associated with the toxinmust be managed through post-harvestprocedures. Research has focused onboth pre-harvest prevention and post-harvest removal of aflatoxins fromgrains. The continuing challenge ofaflatoxin prevention necessitates theneed for improved post-harvest tech-niques to detoxify valuable grainsupplies that would otherwise end up ashazardous waste material.

Aflatoxin decontamination can bedone physically, biologically andchemically. Physical methods such asseparation of contaminated grain bydensity in water, screening or millingresult in loss of product and do notcompletely remove all contaminatedportions. Other physical methods such asheating or irradiation are either cost-prohibitive or non-effective for drysamples. Biological methods, whichinclude development of transgenic cropsresistant to the mold or use of microor-ganisms that destroy the mold, arerelatively harmless to the crop and showsome potential, but they have yet to becompletely effective in decontamination.

A number of chemical methods havebeen successfully implemented for

deactivation of aflatoxins in grains.Treatment with chemicals such asammonia, methylamine and sodiumhydroxide in the presence of moistureand heat have shown potential, butreduced protein nutritional availabilitywas observed in rat feeding tests.Chemical inactivation by ammoniationhas wide-spread use and acceptance, butthe cost is approximately $20 per ton.

Ozonation is a chemical method thatshows potential for decontamination ofgrains containing aflatoxin. Ozone isbecoming a widely used replacement forchlorine-based chemicals for sanitationpurposes in food processing, especiallyin the meat industry and for waterquality purposes, such as bacterial, odor,pesticide and hazardous compounddegradation. Compared to ammoniationtreatment, decontamination withozonation is estimated to cost only about$4 per ton.

One area of research in the FoodScience and Biological and AgriculturalEngineering departments is focused onthe suitability and safety of the ozonationprocedure for decontaminating aflatoxin-contaminated corn. The ultimate goal isnot only 100 percent detoxification ofaflatoxin-contaminated corn, butensuring the product is safe for con-sumption by animals.

Other research at the LSU Agricul-tural Center includes the following:

A breeding approach to productionof resistant corn hybrids. This is a jointproject in the Agronomy Department andwith the Dean Lee Research Station.

In the Entomology Department,

scientists are developing control prac-tices to limit insect damage, therebyclosing off a potential avenue of entryand spread into the ear by the fungus.

At the Northeast Research Station,scientists are assessing managementpractices, such as irrigation and fertiliza-tion, which minimize stress.

In a joint project between theNortheast Research Station and the PlantPathology Department, researchers areevaluating about 75 commercial cornhybrids each year for aflatoxin contami-nation in an inoculated test. Thisprovides information for growers onhybrids to select to minimize exposure toaflatoxin contamination.

LSU AgCenter scientists also areexploring novel approaches to theaflatoxin problem, including chemicaltreatment to turn on corn diseaseresistance genes leading to systemicacquired resistance. A second approachuses the herbicide Liberty on inoculatedLibertyLink and non-LibertyLink corn toproduce ammonia through its interactionwith the fungus and the plant. Ammoniais toxic to the fungus and also directlydegrades the aflatoxin molecule.Preliminary results appear promising. Athird biological control approach appliesa microorganism to the corn ear that isinhibitory to the fungus in culture.

No single method will ensure thecomplete removal of aflatoxin. Amultidisplinary effort can significantlyreduce the risk associated with aflatoxincontamination and yield products safeand acceptable to the consumer, yet cost-effective for producers.

LSU AgCenter Extension conducts “Safe Food Handlers”workshops to help people learn to keep food safe. Notableamong the participants are the food vendors for the NewOrleans Jazz and Heritage Festival. This organization requiresthat all vendors who sell food at this annual event complete this8-hour training course.

A spin-off of this training program is called “Safe Food,Healthy Children.” In this program, extension specialists teachfood handlers from day care centers, preschools and HeadStart centers. Part of this training involves teaching youngchildren about food safety with a “Hurray for Hand Washing”curriculum.

Food safety extension publications available to the publicinclude the following. One copy is free to any Louisiana

resident. You may obtain them from your local parish exten-sion office or order from the Internet at http://www.agctr.lsu.edu/wwwac/puborder.htm.

There’s a Fungus Among Us! Food Molds—An ImportantHealth Concern #2488

Fight Bac #2700

Handling Food and Water After a Storm or Flood #2527I

How to Cook When the Power Goes Off #2527L

Play It Safe with Food After a Power Outage #2527M

Learn to Keep Food Safe


A lthoughAmericans enjoy the

safest food supply in the world, severalrecent outbreaks of foodborne illnesshave heightened concern about foodsafety.

In the United States, between 6.5million and 81 million cases offoodborne illness and as many as 9,100related deaths are reported annually. Inaddition, the risk of incurring foodborneillness is increasing because of morelarge-scale production and distributiontechniques that allow contaminatedproducts to reach more individuals. Thenumber of people in high risk groupssuch as those with suppressed immunesystems and the elderly is increasingalso. Children are more at risk becausemore of them spend significant amountsof time in group settings.

In addition, bacteria have found newmodes of transmission. Some are moreresistant to long-standing food process-ing and storage techniques. Virulentstrains of well-known bacteria haveemerged. The exact cost of foodborneillnesses is unknown, but estimates of thecost of medical treatment and lostproductivity may be as much as $5billion to more than $22 billion annually.

Contamination SourcesAlthough more than 30 pathogens

are associated with foodborne illness, theCenters for Disease Control (CDC)considers E. Coli 0157:H7, SalmonellaEnteritidis, Listeria monocytogenes andCampylobacter jejuni the most impor-

PreventionAccording to the CDC, 97 percent

of foodborne illness can be prevented byimproved food handling practices suchas proper cooking and storage of foodand appropriate personal hygienepractices by food handlers. Sincebacteria are found naturally all aroundus, safe handling is necessary toprevent the bacteria frommultiplying and causingfoodborne illnesses

One of the mostimportant factors incontrolling bacterialgrowth is temperature.Most foodborne out-breaks in the UnitedStates are the result ofimproper temperature control. Heatingfood to a specified temperature andmaintaining that heat for a given time,depending on the food, will destroy mostmicroorganisms. The general rule is toheat foods above 140 to 170 degrees F orout of the “danger zone” where bacteriamultiply rapidly.

FFFFFoodborne Illness:oodborne Illness:oodborne Illness:oodborne Illness:oodborne Illness:ArArArArAre e e e e YYYYYou aou aou aou aou at Risk?t Risk?t Risk?t Risk?t Risk?

Evelina Cross, Professor and Interim Director,and Maren Hegsted, Professor, School of HumanEcology, LSU Agricultural Center, Baton Rouge,La.

Evelina Cross and Maren Hegsted

Table 1. Sources of Food Contamination

PATHOGEN SOURCES FOODS

E. coli 157:H7 Animal and human feces, Raw or undercooked ground beef,untreated water unpasteurized milk, produce

Salmonella Raw meat and poultry, Eggs, poultry products, meat, dairyhuman and animal feces products, seafood, fruits, vegetables

Listeria Soil, plants, water, animal feces, Soft cheese, other dairy products, rawrefrigeration condensate produce, deli items, meat, seafood,

fruits and vegetables

Campylobacter Animals, flies, raw poultry Poultry, unpasteurized milk, rawvegetables, meat

tant. The most common carriers arefoods of animal origin such as beef,pork, poultry, eggs and seafood prod-ucts. But many other foods, includingmilk, cheese, ice cream, orange andapple juices, cantaloupes and vegetables,have been involved in outbreaks duringthe last decade. The sources of contami-nation of food by the four pathogensidentified by the CDC are in Table 1.

Although foodborne illnesses are ofshort duration and do not requiremedical treatment, serious complicationsand death can result. E. Coli O157:H7can cause kidney failure in youngchildren and infants. Salmonella can leadto reactive arthritis, serious infectionsand deaths. Listeria can result inmeningitis and stillbirths, andCampylobacter can cause arthritis, bloodpoisoning and be a precipitating factorfor Guillain-Barre syndrome.

Campylobacter

E. Coli O157:H7Salmonella

Listeria

Illustrations by Elma Sue McCallum


Never leave cooked meat or otherperishable foods at room temperaturelonger than two hours. Keep all coldfoods at temperatures below 40 degreesF and hot foods at an internal tempera-ture of at least 140 degrees F. Freeze orrefrigerate leftover foods immediately.Cut large portions in smaller portions tospeed cooling time, and, to speedcooling, use small, shallow containers.Always reheat leftovers to at least 165degrees F. Sauces and gravies should bereheated to a rolling boil for at least oneminute before serving.

Consistently following these rulesfor safe handling, preparing, storing andreusing foods will greatly reduce the riskof foodborne illness for you and yourfamily.

refrigerator temperature is at 35 to 40degrees F. Store uncooked meat, fish andpoultry products on a plate on the lowestshelf of the refrigerator so raw juices donot drip on other foods and contaminatethem. Always defrost meat, poultry orfish in the refrigerator or under cold

Avoiding cross contamination offoods also is essential to safe foodhandling. To prevent cross contamina-tion, all hands, utensils and surfacestouching raw food should be thoroughlywashed and sanitized before being usedagain for either raw or cooked food. Thisincludes tabletops, cutting boards,knives, forks and slicers as well asaprons, cleaning cloths and sponges.

PersonalHygiene

The personal hygiene practices offood handlers are critical to preventingfoodborne illness. Hands should bewashed frequently, especially beforehandling food, after touching raw meator eggs, after using the restroom,sneezing or handling garbage.

When shopping for food, consumersare advised to notice the “sell by” and“use by” dates to be sure they have notexpired. The “use by” date applies to useat home. Both labels refer to the qualityof the food and are not a guarantee of anuncontaminated product. Examine thepackaging of the items, and do not selectthose with holes or tears. Cold fooditems should be kept cold, and frozenfoods frozen solid. When possible, placeraw poultry, meat or fish in separateplastic bags to ensure that they do notleak and contaminate other unprotectedfoods. Plan to select perishable fooditems, especially meats, just beforeleaving the store to reduce the time thefood is at room temperature. If groceriesmust be left in the car for longer than 30minutes, use a cooler to transportperishables home.

Upon arriving at home, placeperishable foods immediately in therefrigerator or freezer. Be sure the

running water because bacteria multiplyrapidly at temperatures between 40 to140 degrees F.

Keep CleanKeep everything that touches food

clean. Wash hands with hot, soapy waterbefore preparing any food and afterhandling raw meat, poultry and fish. Useseparate platters, cutting boards, traysand utensils for cooked and uncookedmeat, poultry and fish. Prevent juicesfrom raw meat, poultry and fish fromcoming into contact with any otherfoods, either cooked or raw. Alwayswash contact surfaces and utensils withhot, soapy water immediately afterpreparing these products. Use separatecutting boards for each food type. Neveruse the same board for raw meat orpoultry and then for cooked or ready-to-eat foods. Cutting surfaces can besanitized by washing with a solution oftwo or three teaspoons of householdbleach in one quart of hot water, thenrinsing with plain, hot water. Directsneezes and coughs away from food andpreparation areas, and wash hands aftersneezing or coughing. Wash all producethoroughly with clean, drinkable water.

Cook ground meats thoroughly to aninternal temperature of 160 degrees F oruntil the juices run clear. Ground poultryshould be cooked to at least 165 degreesF. Cook beef to at least 145 degrees F,pork to 160 degrees F and poultry to 170degrees F. Do not cook dressing in thecavity of the bird; instead, cook itseparately. Do not partially cook food tofinish later. A temperature high enoughto destroy bacteria may not be reachedwith partial cooking and will allowbacteria to multiply rapidly.

For more informationabout food safety, contact:

USDA Meat and PoultryHotlineMonday through Friday,9 a.m. to 3 p.m. central time(800) 535-4555

Centers for Disease Controland PreventionFoodborne Illness Line24-hour recorded information(404) 332-4597

National Cattlemen’s BeefAssociationwww.beef.org

USDA Food Safetyand Inspection Servicehttp://www.fsis.usda.gov

When in doubt, throw it out!


Non-profit Org.U.S. Postage

PAIDPermit No. 733Baton Rouge, LA

Louisiana Agricultural Experiment StationLouisiana State University Agricultural CenterP.O. Box 25100Baton Rouge, LA 70894-5100

Inside:

The LAES contributes to thiscountry’s safe food supply. .......... Page 4

Seafood is big business in Louisianaand safe because of HACCP............................................................... Page 6

New bar code will help monitor foodsafety. ............................................... Page 8

Louisiana consumers want to knowwhat country their meat comes from..............................................................Page 11

Ozone is a new weapon in the foodcontamination battle. .................. Page 12

The Rapid Microbial Detection and Food Safety Assurance Laboratory was established under the direction of Wanda J. Lyon, a professor inthe Food Science Department, to work with Louisiana meat processors and food manufacturers to assist them with their HACCP (HazardAnalysis and Critical Control Points) plans. (See page 6.) The facility includes state-of-the-art equipment to detect pathogens and toxins in alltypes of foods. This laboratory has a proven record of assisting food processors in their efforts to address microbial hazards. The laboratorywas equipped by funds provided by the state Department of Agriculture and Forestry and is housed in the Agricultural Chemistry Building onthe LSU campus in Baton Rouge, La. The LSU Agricultural Center is seeking funds through the legislature to support this laboratory andother food safety extension activities.

Detection laboratory helps meet food safety needsPh

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food safety issuefood safety issue - ncf-net.org · 2 louisiana agriculture, spring 2000 editorial...

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