INSIGHTS

Agriculture Canada ActivitiesJor Salmonella Control

Veterinary InspectionDirectorate

The Veterinary Inspection Direc­torate (VIDI is the operational groupwithin the Food Production and Inspec­tion Branch which is responsible forimplementing the Animal Health, MeatHygiene, and Hatchery and PoultryGrading programs. The headquartersfor the directorate are located inOttawa and there are seven regions,each with its own regional office, aswell as many district or plant offices.The technical staff of VID is composedof 524 veterinarians and 1406 primaryproducts inspectors who are predo­minantly involved with either meatinspection or animal health duties.Recent branch efforts to furtherimprove efficiency and to eliminateduplication have required officers to beincreasingly involved in both programs.

Meat inspection is conducted in 570federal establishments and in 55domestic plants. Through federal andprovincial agreements, a number ofprovincially registered plants alsoreceive federal meat inspection serv­ices, although their products are soldonly within these provinces. The prin­cipal objectives of the Meat HygieneProgram are to ensure a safe andwholesome supply of meat and poultryproducts for domestic and foreign con­sumption, and to ensure that theproducts are correctly and accuratelylabeled.

In animal slaughter plants, antemor­tem and post-mortem inspections areperformed on each animal slaughteredin order to detect any condition thatwould render it unfit for food. Clinicallyhealthy animals that intermittentlyshed Salmonellae are recognized to bethe main source of contamination forslaughter and processing plants. Forthis reason, an important activity ofVID personnel is to detect any visibletraces of contamination on eachslaughtered carcass and to make surethat it is eliminated, thereby reducingthe risk of cross contaminationthroughout the food chain. In addition,all vehicles that transport live animalsare cleaned and disinfected under offi­cial supervision before leavingregistered premises. This helps preventrecontamination with Salmonella at thefarm level.

Can. InSf. Food Sci. Techno!. 1. Vol. 20, No.5, 19S7

In processing plants, the surveillanceof processing methods is carried out toensure destruction of Salmonella inready-to-eat products.

As well as monitoring individual car­casses and processes, the VID inspec­tionaI staff enforce the federal stan­dards established for plant sanitation.Both the slaughter and processingplants must comply with constructionand equipment standards to ensureproper sanitation and hygiene ofproducts for Canadian and foreign mar­kets. Equipment must be constructedto allow dismantling for daily cleaningand sanitizing. Pre-and post-operationalcleanup and sanitation are monitoreddaily or accordingly to a Frequency ofInspection Level (FOIL) approach.

Within VID, there are also 531 staffmembers who administer the AnimalHealth Program. These employees arelocated in district offices, at interna­tional airports and seaports, and at U.S.ports of entry. The objective of theAnimal Health Program is to keep thecountry's livestock and poultry freefrom currently exotic contagious andinfectious diseases. In order to preventthe introduction of foreign diseases,inspectors examine all livestock, animalproducts, and meat and meat productspresented for entry into Canada, aswell as personal belongings of travelersentering Canada. For instance, inresponse to the public health hazardcaused by pet turtles as asymptomaticcarriers of Salmonella spp., VID cur­rently enforces regulations limiting theimportation of turtles and tortoises.

In order to control and eradicate dis­eases existing in Canada, VID staffmaintain extensive testing and eradica­tion programs, which serve to reducethe incidence of diseases and toeliminate infectious animals that mayfurther propagate a particular disease.As an example, the Pullorum/Typhoid(S. pullorum and S. gallinarum) Eradi­cation Program for poultry requires theroutine testing of primary breedingflocks and hatchery supply flocks.Exhibition/game birds are also tested atspecified intervals. The program objec­tive is to declare pullorum/typhoid dis­ease exotic to Canada before the endof 1987.

VID is also responsible for themicrobiological monitoring of fluff sam­ples taken in hatcheries on a FOILbasis. This system of inspection isdesigned to focus efforts on hatcher­ies having a greater incidence ofSalmonella.

Canada has established an interna­tional reputation for the high quality ofits animal products and for the animalbreeds that it has refined. This reputa-

tion has opened many doors for inter­national trade. At present, livestockand meat industry representatives canenjoy the lucrative position of havingvery competitive markets for theirproducts at home and abroad. The neteffect of this is that livestock andanimal products constitute an impor­tant percentage of the total agriculturalexport dollar. This success is in partdue to the committed efforts of thestaff of the Veterinary Inspection Direc­torate.

Agricultural InspectionDirectorate

Within the Food Production andInspection Branch, the AgriculturalInspection Directorate (AID) worksclosely with all sectors of the agri-foodindustry, from producers throughprocessors to packers and shippers. Inorder to ensure that a high standard ofquality is met, the Directorate providesan inspection and monitoring servicefor a diverse range of products andprocesses including seeds, feeds, fer­tilizers, pesticides, plant health, dairyproducts, fresh fruits and vegetables,processed products, and eggs and eggproducts. The following is a summaryof the Directorate's activities withinthese commodity groups.

Dairy

AID works closely with dairy proces­sors to assure the high quality ofproducts through:• registration of all dairy product

plants to ensure sanitation stan­dards are met;

• inspection of imported and domes­tic processed milk products; and

• inspection of labeling, packaging,weights and composition.

Within dry milk powder plants,product and environmental monitoringprograms (Fall 1986 issue of Safetywatch) contribute to the assured safetyof Canadian dry milk products for con­sumers and foreign customers. In theevent that a product is found positivefor Salmonella, it is put under detentionor recalled if it has already been dis­tributed. The local offices of bothHealth and Welfare Canada and AIDwork cooperatively to locate and con­trol products under recall.

If environmental samples of a drymilk powder plant are found positivefor Salmonella, the plant is requestedto develop an action plan of correctivemeasures. A follow-up inspection ofthe environment is performed after theplant has completed the necessarycleaning and sanitizing procedures. Fur­thermore, a plant with a Salmonella-

fA / 289

positive environmental sample is put ona tighter Frequency Of Inspection Level(FOIL) for its products until the situa­tion is corrected.

Eggs and Egg Products

The directorate conducts the follow­ing inspections to assure the quality ofeggs and egg products:• monitoring of the sanitation of egg

grading stations and processed eggplants;

• environmental microbiological sam­pling of plant air, equipment andpremises

• monitoring of grading, packagingand labeling; and

• inspection of all imported productsas well as products for export.

An environmental sampling plan is inplace to monitor Salmonella at the plantlevel. Product samples are taken at theplant and wholesale levels. Effectivefollowup measures are taken whenpositive results are discovered.

The inspection program is audited onan ongoing basis, and a copy of theaudit report for each plant is forwardedto the Health Protection Branch ofHealth and Welfare Canada as well asto Agriculture Canada Headquarters inOttawa.

Feeds

The Directorate helps to assure thenutritional value and safety of all animalfeeds by:• monitoring the safety and quality of

all feeds manufactured, sold andimported into the country;

• giving special attention to the safetyof medicated feeds;

• investigating residues found inmeats which may be related tofeeds; and

• inspecting feed manufacturingestablishments.A surveillance program exists for the

detection of Salmonella in feeds. Theregional staff in each province areresponsible for the collection of thesesamples from feed manufacturers,ingredient suppliers and on-farm sites.

When Salmonella contamination hasbeen identified, follow-up measures aretaken to ensure:• improved production practices/sani­

tation are undertaken at the plant;and

• plant management is advised of anyneeded employee education toemphasize proper product-handlingtechniques.

290/ IA

Laboratory Services Division

The Salmonella Unit of the FoodLaboratory, Laboratory Services Divi­sion, analyzes approximately 8 000samples annually for the presence ofSalmonella spp. These samples consistof processed food products, animalfeeds or environmental samples fromdairy and egg processing plants. Thesamples are taken at the plant by AIDinspectors in the case of processedfood products and environmental sam­ples, and at the rendering plants, feedmills, dealers and farms in the case ofanimal feeds and ingredients. In thefood sector, the emphasis is currentlyon environment sampling in the plants.The analysis of environment samplesrequires less preparation time than thatfor product samples and, by controll­ing the occurrence of Salmonella in theplant environment, the likelihood ofcontamination of the product is greatlyreduced.

The effectiveness of the AgricultureCanada Salmonella program is indi­cated by the low rates of Salmonella indried milk and in processed eggproducts. In the last four years, theaverage number of positive samples forthese products has been 0.3 % and0.6 %, respectively. The percentage ofenvironment samples found to be posi­tive over the same period are 1 .4 % fordairy plants and 4.6 % for egg process­ing plants. The program covers allregistered dried milk and egg process­ing plants. Whereas the Ottawa labora­tory examines samples from Ontario,Quebec and the Maritime provinces,samples from the western provincesare analyzed by the Calgary laboratoryof the Laboratory Services Division. Inanimal feeds and feed ingredients, thepercentage of samples found positivefor Salmonella has been consistentlybetween 15 % and 20 % for a numberof years. The highest levels of contami­nation have been found in renderedanimal products (meat and bone meal,blood meal, feather meal, dried poultryby-product, etc.).

Continued attention to quality assur­ance and the acquisition of newerlaboratory methodologies when indi­cated will enable the Laboratory Serv­ices Division to continue to provide thenecessary diagnostic support for theBranch's Salmonella Program. For fur­ther information contact: Salmonellaand Food-borne Disease Unit, Health ofAnimals Directorate, Food Productionand Inspection Branch, AgricultureCanada, 2255 Carling Avenue,Ottawa, Ontario K1A OY9 (or call613-995-5433).Reprinted from Safety watch Food-borne Disease Bulle­tin No 4, 1987.

Why Do WJ;:Age O~~ Beef?'V"' ....>.. ''''~1''

'1\\

It is widely assumed that a coldstorage period for beef carcassesenhances the tenderness of meat. Forexample, many restaurants andretailers advertise that their meat isproperly "aged". The purpose of thisarticle is to explain the reasons whybeef processors have traditionallystored beef carcasses in the cold priorto sale of retail cuts and to attempt toprovide a reasonable scientific explana­tion as to why this was needed in thepast and what it means in terms ofmodern methods of beef production,handling and storage.

In order to understand why "ageing"was once very important to meattenderness, we must first examine thebasic components of tenderness. It iswell accepted that two factors contrib­ute to "toughness" in meat: "back­ground" or inherent toughness and"rigor" or contraction toughness.

Background toughness is thought tobe caused by the amount of connectivetissue in the animal. Connective tissueis the protein matrix which binds mus­cles to bone, and also provides attach­ment of adjacent muscle fibre bundleswithin the muscles. Connective tissueis made of several proteins, but themajor component is collagen, an insolu­ble protein which has many crosslinksand is very high in tensile strength. Theamount of collagen in muscle is relateddirectly to the age and size of theanimal. Young animals have relativelylow amounts of collagen, while olderanimals have increasingly higheramounts. Also, muscles which workhard will develop more connective tis­sue than muscles which do little work.Collagen, due to its tensile strength, ishard to chew, and does not readily dis­solve in the mouth. Hence, meat withhigh collagen content, such as oldoxen, is perceived as "tough", andmeat with low collagen content, suchas 2 months old veal, is perceived as"tender". Collagen can be degraded tosoluble "gelatin" by simmering forseveral hours; therefore, meats high inconnective tissue, such as shank,oxtail and neck meat, require longperiods of moist cooking in order tosolubilize the collagen and thus "ten­derize" the meat.

Rigor, or contractile toughness, isthought to originate from the ability ofmuscles to contract even after theanimal has been slaughtered. This isthe result of the very well understoodbiochemical and enzymatic processthat causes muscle to contract in thelive state, i.e., the interaction of ATP

J. Insf. Can. Sci. Tee/mol. Alimeflf. Vol. 20. No.5, 1987