I=LSGP-G-82-001 C. 2

January 1982 Oyster Prodoction:P ant Workers

W. Steven Otwell

Florida Sea Grant CollegeMarine Advisory Bulletin MAP-21

IMPORTANT NOTE

This manual has been prepared with reference to the guidelines recommended by the National ShellfishSanitation Program and the Florida State Regulations specified in the Rules of the Florida Department ofNatural Resources. This manual does not replace or interpret these recommendations and regulations, butshould be used to supplement these references.

SPECIFIC REFERENCES

National Shellfish Sanitation program Manual of OperationsPart I Sanitation of Shellfish Growing AreasPart II Sanitation of Harvesting and Processing Shellfish

1965 Revision with amendments as communicated through the U.S,Food and Drug Administration, Shellfish Sanitation Program,Region IV Office, 1182 W. Peachtree St., NW, Atlanta, GA 30309

The Florida Comprehensive Shellfish and Blue Crab Control Code, Chapter 16B-281979 corrected copy with amendments as communicated throughthe Bureau of Marine Resource Regulations and Development,Florida Department of Natural Resources, 3900 CommonwealthBlvd., Tallahassee, FL 32303

Publication design, layout, and illustration page 4! by Laurie A. Walsh.

W. STEVEN OTWELL, seafood specialist, Sea Grant Marine Advisory Program, is an assistant professor inthe Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences {IFAS!,University of Florida, Gainesville, Florida.

Contents

Introduction ..

Health ..

Processing .

Shell stock

Shucking

Skimmingand Blowing

Packagingand Storage ..

Clean-Up andWaste Oisposal.

Regulatory Agencies ..

Introduction

Shucking and processing oysters is a proud pro-fession which requires hard work and training. Anexperienced worker has learned special techniquesfor opening the shells and removing the oysterswithout damaging or contaminating the 'meat'.Numerous attempts to develop oyster shuckingmachines have failed because opening the irregularshaped shells requires unique methods and care.Thus, oyster production is a specialized form offood processing which requires skilled labor.

Oyster production requires more care and atten-tion than other types of food processing. Unlikebeef, pork, poultry and fish � oysters are commonlyeaten raw. Raw oysters are harvested from an en-vironment that can carry harmful bacteria and con-taminants which can threaten the health of con-sumers. Oysters are filter feeders which means theyfilter materials from the water as it is pumpedthrough their gills. Oysters, therefore, can concen-trate materials in their bodies to several times theamount found in the water, When raw oysters areconsumed, any bacteria or contaminants present orgrowing on the raw oysters will also be consumed.Thus clean growing waters, sanitary handling prac-tices, and proper refrigeration are of vital concern insafe shellfish production.

Occasionally, a consumer will suffer illness fromeating poor quality oysters. The result is discomfortfor the consumer and bad publicity which couldthreaten the jobs of all workers in the oyster in-dustry. In fact, since raw oysters have the unfor-tunate reputation of causing food illnesses, they aresometimes blamed for sickness caused by otherfoods. Thus, it is the responsibility of all workers toassure that oysters are harvested from approvedwaters and are shucked and processed undersanitary conditions which prevent contaminationand potential illnesses.

This manual has been prepared as a brief guidefor workers in the oyster industry. Most of this infor-mation is good common sense. This informationshould be used along with the rules and regulationsof the various health and regulatory authorities toassure the production of safe, top quality oysters.

* "Bacteria and Seafood" is a free booklet which explains bacteria problems associated with Seafoods, Ask for Florida Sea GrantMarine Advisory Bulletin, NiAP-22, 3982.

" The above statement assumes the oysters are harvested from clean approved waters or after an approved relaying operation.Relaying and depuration operations for moving live oysters from contaminated to clean waters can remove some harmful con-tamination, thus improving the oyster quality,

Health

All workers tnust be in good health while process-ing oysters. Human illnesses can be contagious toother workers and can contaminate the oysters withdangerous bacteria or viruses.* A common cold,cough, running nose, or infected eye can also causeproblems. No person should report to work if theyare sick or have infected wounds, sores, boils,pimples, or respiratory infections. In some areas ofFlorida, all workers harvesting and processingoysters for commercial use must obtain a HealthPermit. This permit is to assure and promote the im-portance of good personal health when handlingoysters. Procedures for obtaining these permits canbe explained by the local county health depart-ments.

ProcessingOyster processing is the entire system of opera-

tions for the production of edible oysters. The firststep in the operation is harvesting. Oyster process-ing begins as soon as the oysters are removed fromthe bottom. The quality of oysters will never be bet-ter than at the moment of harvest." After harvest,natural chemical reactions and the presence andgrowth of bacteria will gradually decrease oysterquality.

Noticeable changes in quality could be develop-ment of odors, cloudy fluids, bad flavor, anddiscoloration. Also, harmful bacteria and virusescould be present and growing to dangerous levels.Growth of harmful bacteria is not always noticeable,Thus, when processing oysters, workers must usemethods of storage and handling which preservethe quality, prevent spoilage, and keep oysters safefor consumers.

Shellstock

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BEFORE

AFTER

All commercial oysters must be harvested fromapproved wafers as determined by state enforcedregulations. Bacterial surveys indicate approvedwaters are not likely to carry types of bacteria whichcould be harmful to consumers. Most states alsoenforce a size law � inches at greatest dimension!to protect the oyster stocks and to assure a betterquality product.

Workers should never harvest, purchase, or pro-cess dead or dying oysters. Dead oysters are riotalvvaya easy to detect, but gaping is a sign of death.lf the oysters are gaping and remain open Hfteragitation, then they are probably dead, Oysters diewhen they are mishandled, improperly stored, ordiseased. Dead oysters can spoil rapidly or containharmful bacteria. It is interesting to note thatspoilage bacteria, which cause changes in odor andflavor, are not necessarily the same types ofbacteria which can be harmful to consumers.

Regardless of which type of bacteria is present,spoilage or harmful types, both can cause problems.

Naturally, all shellstock will contain somebacteria, During warm months it is necessary to pro-tect the shellstock from overheating in the aun. Asthe temperature of the shellstock increaaea, theamount of bacteria in the surface mud and insidethe shell can increase. During cold months theoysters can remain on the boats for more than aix toeight hours, but in summer months, the oystersshould be protected and brought to the dock assoon as possible. Florida's Seafood Quality ControlCode requires that the cargo be protected from theaun and weather, This is best accorripiished by ashade or canopy over the oysters on the deck,

Oyster QveA'ty Ceo 8e No 8etterThen At The MOment Qf 8@West

When approved ahellstock is delivered tc theplant it should be clean. Although vvaahing requiresa little extra vvork, it wIII remove excess mud, lf un-necessary amounts of mud enter the processingand storage areas, it can contaminate vyorking aur.faces, workers clothing and shucked oysters. Bothspoilage and harlYlfuI types of bactena can grow inmud.

The best time to vvash oysters is when they arebeing removed from the water or when loaded onthe boat, A simple sloshing action with the oystertongs can remove loose mud before unloadingoysters on the culling board or deck, and a smallbattery pump can be installed to provide a hosedspray to remove sticky mud. If the oystermen areharvesting from approved waters, then the oysterscan be washed with approved water which has asimilar salinity and temperature. Qystera shouldnever be washed with water from unapproved areas,and the boet should have a removeable false bottomto prevent bilge water or vyaah water from coming in.to contact vvith the clean cysters, lf the oysters arewashed at the dock, then workers must make sure

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sooroas IONR! rr?aiotaios eo atlas of ooastajareas approved for harvesuott oysters.

SHELLSTOCK BEFORE AND AFTER WASHING

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to use clean wash water, The muddy vvater must bedirected away from the processing area to avoidcontact vvlth floors, containers, and vvorkersclothing and boots,

After washing, the sheiistock should be stored ina clean cool area. The recommended storagetemperature should not exceed 45 F, Fven in eccltemperatures bacteria wiH continue to grow, if thestorage temperature is decreased, then the bacterialgrowth rate wiH decrease, A good rule of thumb is toship or shuck aH sheHstock vvithin 48 hours afterharvest.

Shucking

There are several methods used to hand-shuckoysters. Workers like to use the most comfortableand rapid method. The plant manager ~ants to usethe method which produces the most clean, un-damaged oysters. UsuaHy the method wiH dependon the individual worker's skill and the size and typeof oysters. The best method carefuHy cuts theoyster muscle away from the sheil and does not tearthe 'meat'.

The three basic oyster shucking methods arestabbing, chipping, and grinding.

VVhen stabbing oysters, workers force the point ofa thin blade oyster knife between the two oystershelis, Inexperienced shuckers stab the oystersalong the hinge or 'heel' of the shells, then twist theknife to pry the shells apart. Stabbing along thehinge sr'ea can damage the knife point and tear' theoysters. Experienced shuckers stab the sheHs alongthe edge or 'beak' at a point near the muscle attach-ment. Thus, when the knife enters the shell, themuscle can be c! eaniy cut and the top she H removed,

Grinding and chipping methods provide an open-ing for inserting the knife blade along the edge of

the shells, Grinding refers to the electrical machinesthat grind an opening, These methods require lessforce to enter the sheH, but they mix smaH pieces ofsheH with the shucked oysters,

Regardless of which method is used, workers'clothing and utensHs should be clean, as vveli as thework area. When the oysters are removed from thesheH, they can be contaminated with more bacteria,Clean clothing end the use of rubber gloves andaprons help reduce bacterial contamination. Rubberand plastic materials may be difficult to work with,but they do not absorb water, slime or bacteria, andthey are easier to clean than cloth, At no timeshould workers remove clothing, shirts�shoes andsocks while shucking oysters. Hats, hairnets, andscarves are recommended to prevent loose hairfrom faHing into the shucking buckets,

Airways Pash Hands Thoroughly AfterEv'ery Work Break, l.inch Time, and

lfisits to the Bathroom

UtensHs including knives, buckets, and pailsshould be cleaned and sanitized on a regularschedule, The shucking containers should be rinsedin running tap water before each refiHing. The use ofdipping buckets for frequent rinsing of the knife isProhibifed. A three compartment sink is required forcleaning and sanitiz'mg aH utensils and small equip-ment. This sink is not for washing hands. The firstcompartment is for washing to remove dirt, slime,and food particles. The second compartment is forrinsing. The last compartment is used for a sanitiz-

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Cloth gloves are often preferred because they are easier to workwith, but they cen become worn and soaked, used cloth gloves wglcontain bacteria which can contaminate fresh shucked oysters.

ing treatment, Rinsing between washing and sanitiz-ing removes the dirt and detergent film which wouldprevent an effective sanitizing treatment. Properdraining and drying completes the cleaning pro-cedure. Until further use, the utensHs should bestored in a clean location protected from splashes,dirt, handling, end contact with food. Knives, gloves,end aprons should nof be taken home because theycould be exposed to harmful bacteria, from Hl-nesses, pets, or unsanitary storage conditicns.Utensiis should remain stored in e dry location inthe plant.

Wooden materials should not be used in theshucking operation. Wooden shucking blocks, cut-ting boards, boxes, benches, stools, end tables eredifficult to clean and wiH support bacterial growth,Wood requires frequent painting or mey becomecracked, splintered, end soaked. Smooth surfacesof concrete or non-toxic mete! ere recommendedbecause these materials ere easier to clean end donot absorb or promote bacterial growth.

Temperature control is the best method to limitbacterial growth. Bacteria will grow or multiply morerapidly in warmer temperatures, For exemple, whenfresh, shucked oysters ere stored for 5 days et 50'F,the number of bacteria present can increase over1936 times, but when oysters from the same batchare stored for 5 days et 3T.O' F, the bacteria may notincrease more then 5 times. Although the bacteriacontinues to glow et both ternpeiatures, the Ioweitemperature �7,5'p near freezing, slovvs the rate ofbactedel growth. Workers should try to keep theoysters cold during shucking, skimming, bicwing,and storage.

The temperature control guideHne for shuckingoysters is that all fresh oysters should be cooled tobelow 45 F within 2 hours after shucking, To meet.this guideline, especially during warm months,workers must prevent overheating of the shellstock.Starting with refrigerated shelistock leeds to ecooler shucked product. Do not let pHes of

Grhdting, eating, smoking and tobacco chewing should be tsrohgsftedin the work area, Handling food or tobacco cen transfer bacteriafrom the workers mouth to the fresh shucked oysters.

Growth of bacteria on fresh oysters peeked in gallon sans and storedat 379'F � ! or 59 F - - -!, References: Kelly, C.B. 1964, Time-Ternperature Effect on Baeterlo!ogioa! Quality of stored oysters.Proosedings Fifth hiational She!Nish Sanitation srorksho!s, ave!!aÃefrom Shegfish Sanitation Branoh, Food and Drug Adrn!nistration,Washington, D.C.!

shel stock remain on the shucking benches over-night. A shucking schedule should be managed tocontrol the temperature of fresh shucked oysters. Inlarger operations, smeller shucking pails can beused far more frequent trips to the pecking roam.Some workers have placed ice in the shuckingbuckets �/3 cen full! to lower the temperature of thefresh aysteis. Remember, certain bectei'te cen sui"-vive in ice, so the ice should be clean,

which increases the yield. An experienced plantmanager controls the blawing time, depending onthe season and size oysters, to produce an attractiveproduct that is not over-soaked. In Florida, the legaltime limit for blowing aysters is 15 minutes. Over-soaked oysters could lose water after they ere pack-ed and may not meet market standards, Also, waterin the blawer should be changed on a regularschedule to prevent bacterial build-up. An excellentway to keep the oysters cool is to use crushed,clean ice in the blower water.

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Skimming end Blowing

Skimming end btavving Operetiane Cen be uSed tadrain and clean oysters before pecking. Fresh,shucked oysters should be clear!ed end packaged ina room separated from the shucking roam. Thisseparation prevents shell, mud, end unauthorizedworkers from contaminating the cleaning end peck-ing cperetians. Only euthanzed personnel should beallowed in the peckmg room end oysters shoutdnever be returned from the pecki~g room ta theshucking room.

The skimming operation washes oysters vvith eclean, chilled water spray to remove dirt, slime, eridsrnetl pieces of shell. Excess water mixed with theoysters witt drain through smelt hales in the skim-ming table. Since oysters come in direct contactwith the skimming table, the surface af the tablemust be cleaned end sanitized regularly..

The blowing operation is e cteening process thatcen improve the appearance af the oysters. Theaeration In the blavving tanks stirs the oysters inclean meter to remove more dirt encl pieces of shell.White the oysters are in the tank, they absorb vveter

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oysters should he spray vrsshad with pre-ehg!ed, !s!ean vratar on thesk horning table,

LAST SALE DATE indicatesthe 14th day after shuskiniI,Florida Iarr prohrbtts.sale offresh oysters 34 days aftershu ck Inil,

CornpenV name, address, andcertification number cart beUsed to trace the oVsters totheir point of origin.

Packegiing arid Storage

Containers for packing oysters must be clean enddry, and each container must have a permaneritlabel. Information on the labels ta Important end canbe used to trace the source of the oysters in ceae ofiHneases or market problems. In Florida, aHpackages of fresh oysters must be lebeHed with a'terminal sale date'. This date is 14 days after theoriginat shucking dey.

Fresh packed oysters should always be stored attemperatures between 32' to 4O" F untH purchasedby the consumer. Frozen oysters should be stored etor below O' F. It ia illegal to thavv frozen oysters forsale es fl'esh Qyatel'a,

Pecked oysters or sheltstock which ia shipped bytruck should be refrigerated et 40 F or below, Whenstoring containers or begs, they should be arrangedto aHow cool eir circulation around, under, endabQve the packages. If the pack8gea are 808nged lne tight bunch, completely fiHing the refrigerato ortruck, then the center of the bunch wHI not be cooledend bacteria wHt begin to multiply.

Deity Qyater' plocesalng operations ere not cQIYI-p!etc untH the processing house ia cleaned end etlwaste removed. Good cie8fi.up and waste disposalhelps reduce bacterial build-up in the house encldiscourages insects and rodents, Critical clean-uppoints in the shucking rocms ere benchea, stools,knives, buckets, gloves, aprons, end the floor.Critical points in the pecking room ere the akirnmertables, the entire blower system, end the floor. Asimple water splay Ql' hosing down ls not adequatecleaning,

Proper cleaning begins vvith e clean, cool waterrinse to remove excess dirt end large particles. Nextthe equipment and surfaces should be scrubbedthoroughly with detergent. Aftel' the excessdetergent is vveshed away with a second clean waterrinse, the surface should be sanitized. Sanitizingkills the invisible bacteri that cen remain even afterscrubbing with detergent. Chemical sanitizingagents and/or hot water solutions should bespecified by the plant manager, Knives, buckets,skimming tables, end blower systems should besanitized at the end of every worA day, EIenches,shucking steHs, and floors should also be sanitizedd el ly,

AH waste materials, empty boxes, used con-tainers, and trash should be moved outside theplant. Outside Waate Starage ShOuld be COnteined tOprevent attracting insects, rodents, end dogs. Altwaste should be picked up on a regular schedule.

LABFL INFORMATION REQUIRED ON EVERY

CONTAINER OF F RESH OYSTERS

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Fresh packed ossters should be stored with sn internal temperaturebetween 32 F to 40'F,

RECQIyIWIENDED CLEAItIING I ROI:EI3URE

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Rinse away remaining detergent before final sanitizing treetntent,

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Regulatory AgenciesRegulation of oyster production is a complex Iob

involving both harvesting waters and oyster pro-cessing operations. At the federal level, a NationalShellfish Sanitation Program NSSP! has beenestablished. This program is a partnership betweenthe U.S. Food and Drug Administration, variousstate shellfish programs, and the oyster industry.This partnership follows a recommended set ofguidelines and standards estabiished for growingwater quality, harvesting, and processing.

ln Florida, the State Shellfish Program is in theDepartment of Natural Resources DNR!. This pro-gram is divided into two sections. The Shellfish En-vironmental Assessment Section located in St.Petersburg monitors shellfish harvesting areas. TheBureau of Marine Resource Regulations andDevelopment located in Tallahassee inspects andcertifies processing operations. Also a DNRmicrobiology iaboratcry in Apaiachicola tests forthe number of certain bacteria in water samples andoysters.

Other state agencies are also concerned vvithoyster quality and safety. The Florida Department ofAgriculture and Consumer Services is pnmariiy con-cerned with the quality of oysters in retail opera-tions, seafood markets, and grocery stores. TheFlorida Department of Health and Rehabilitative Ser-vices HRS! is primarily concerned with oyster quahtyand safety in restaurants and other places oystersare served to consumers. This agency is alsoresponsible for issuing Health Permits required forworkers employed to harvest and process oysters.

All Florida state agencies can be contactedthrough their local county offices or by direct con-tact with the main office in Tallahassee,

Florida Sea Grant College is supported by award of the Office of Sea Grant. National Oceanic and Atmospheric Administration, U.S. Depart-ment of Commerce, grant number NABOAA-D-00038, under provisions of the National Sea Grant College and Programs Act of 1966. Thisinformation is published by the hlarine Advisory Program which functions as a component of the Florida Cooperative Extension Service, JohnT, yyoeste, dean, in conducting Cooperative Extension work in Agriculture, Home Economics, and Niarine Sciences, State of Florida, U.S,Department of Agriculture, U.S. Department of Commerce, and Boards of County Commissioners, cooperating, Printed and distributedinfurtherance of the Acts of Congress of hfey 8 and June 14. 19 14. The Florida Sea Grant Collage is an Equal Employment Opportunity-A ffirma-tive Action employer authorized to pmvide research, educational information and other services only to individuals and institutions that func-tion without rejsrd to race, color, sex, or national origin.

Copies available from:

ThiS public document was promulgated at a cost of $1312.00, or 26.2 cents per copy, to provide guide-lines regarding sanitation and production methods to persons involved in the oyster industry. 2- 5M -82

Marine Advisory Program

Florida Cooperative Extension Service

GO22 McCarty Hall

University of Florida

Gainesville, F L 32611

Preparedin cooperation with theFlorida Department of Veteran and Community Affairs and theFlorida Sea Grant Marine Advisory Program

with funds from the

Economic Development Administration and theFlorida Sea Grant College Program