Prof. Jackson N. Ombui Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Kenya.
Meat hygiene is the creation of conditions and implementation of measures necessary to ensure the safety and suitability of meat at all stages of the meat production chain. Effective hygiene control is vital to avoid the adverse human health and economic consequences of unsuitable meat and meat related illnesses.
Quality assurance is the process of ensuring that meat will not cause harm to the consumer when it is prepared and eaten according to its intended use. Everyone including farmers, processors and regulators have a responsibility to assure consumers that meat is safe and suitable for consumption
Safeguard the health of the people through production, distribution and consumption of safe meat; Promote national and international trade of meat; Prevent avoidable meat losses and promote conservation of livestock resources.
Meat hygiene programs are aimed at controlling the hygiene standards of the meat at all levels of meat production chain including: oprevention of disease in animals omaintenance of appropriate nutritional level of food animals, oprudent use of veterinary medications and other chemicals in food animals and observing the recommended withdrawal periods, oensuring use of appropriate use of methods of slaughter,
o thorough ante-mortem and postmortem inspection, o hygienic transportation of meat to butcheries and/or markets o ensuring the hygienic state of the butcheries and meat markets, o Ensuring appropriate meat storage conditions before they reach the consumer.
o Prevention of contamination of meat o Prevention of meat deterioration and spoilage by controlling temperatures, humidity.
1. Prevention of food borne disease outbreaks. Food borne diseases leads to consumer suffering and loss of life. 2. Prevents meat deterioration that may lead to unnecessary losses 3. Enhances local and international trade in meat due to enhanced consumer confidence 4. Creates employment as more income is realized from sale of meat.
Meat quality Assurance is the systematic implementation of planned meat hygiene measures along the meat production chain to provide adequate confidence to the consumers that meat is safe for their consumption. Meat Quality assurance systems are a set of regulatory and non-regulatory institutions involved in activities aimed at ensuring the safety of meat (e.g. the meat Control Act., Meat law, meat standards )
Meat quality assurance system focuses on prevention, elimination, control or reduction of hazards to acceptable levels throughout the meat production chain. A hazard is a biological, chemical or physical agent in food with a potential to cause an adverse health effect.
Biological hazards: which are microorganisms (bacteria, viruses, yeast and molds) and their toxins that may be found in food Chemical hazards e.g. cleaning chemicals, pesticides, drug residues, heavy metals, allergens etc. Physical hazards e.g. foreign bodies such as stone, mud, glass, plastics and metals.
Food hazards are the cause of food borne diseases that leads to consumer suffering and loss of life. Food borne diseases are diseases that are transmitted to humans through consumption of a disease agent (hazard) in the food e.g. meat. Considerable costs arise due to associated medical treatment, lost production, recalls and disposal of faulty products.
In addition, outbreaks results in bad publicity, loss of market for the meat product, and may lead to legal costs related to illness or loss of life. Meat quality assurance system approach is based on GAP, GHP, GMP, SSOP and Hazard HACCP system, food safety management systems and traceability/recall systems. The GAP, GHP, SSOP are measures that are required to produce safe food by minimizing Food hazards at primary production.
Keep food animals free of diseases through regular vaccination and treatment. Prevent accumulation of chemical residues by feeding animals with clean feed (free pathogens, aflatoxins, heavy metals and other toxicants) Prudent use of veterinary drugs and observing withdrawal periods before animal slaughter. Providing animals with clean water and appropriate housing conditions. Minimize non-therapeutic use of antibiotics or hormones
Facilities must be available for the isolation and removal of any animals showing signs of illness. Pressurized water is preferred to wash animals prior to slaughter Animals must be adequately rested before slaughter for 12hrs. Food should be withheld 12hrs before slaughter. Ante-mortem inspection must be diligently carried out to detect sick animals.
Slaughtering should be done on tables or on hanging rail to reduce contamination by regurgitation The slaughtering knife should be cleaned and sterilized between each carcass at 82 C. The head should be removed and after skinning washed separately from the carcass.
After the initial cut through the skin, sterilize the knife in water at 82 c and then make all other cuts from the inside out. No hair or skin pieces should be left on the skinned carcass. No excess blood should appear on the skin of the carcass. Prevent contact of dirt from hides and skin to the meat surface. Prevent contamination of the carcass with dirty hooks, knives and protective clothes.
Do not puncture the viscera (alimentary tract), uterus, urinary bladder and gall bladder during separation cuts. Prevent contact of viscera with floors, walls or stands. Regularly wash hands/aprons and sterilize knives, especially after any time contamination occurs. Careless evisceration must be avoided to prevent contamination of the carcass with gut contents.
Carcass splitting Carcass splitting saws should be sterilized between each carcass. Carcass washing Carcasses should be washed after spliting using cold potable water and if possible decontaminated by use of chlorinated water containing (50-100ppm).
During post-mortem meat inspection, palpation and incision of lymph nodes, infected tissues or tissues with abnormalities can give rise to cross contamination. Incision should therefore be avoided where possible, and palpation of organs should be minimal.
Appropriate protective clothing should be worn and replaced each day or when heavily soiled. They should be of light color, preferably white and be clean and tidy. Hands and arms should be washed and knives and equipments regularly sterilized using hot water.
Workers must wash their bodies regularly and have the nails trimmed as much as possible. Nail polish and dyes on nails and hands should be discouraged. Beards should be shaven or covered by a turban. They should not move from dirty to clean areas, but vice versa.
Workers should not use heavy perfumes, lipstick, false eyebrows and eye shadows. Washing facilities should be provided where workers can wash before leaving and a canteen where they could take refreshment and rest during breaks. Workers must go for medical check-up after every 6 months
Proper cleaning and sanitation of the slaughter floor, walls and equipment should occur daily and frequently during the day. Sanitary Standard operation procedures (SSOPs) for cleaning and sanitation of all parts of the plant should be in-place and wellimplemented.
Contamination at the farm with pathogens and chemical residues Dirty feet, hides and skin during flaying Butchers tools (Knives, pangas, axes etc) Intestinal and stomach contents during evisceration Poor quality water used to wash carcasses Poor personnel hygiene and habits. Contaminated meat carriers Dogs, birds rodents and insects that gain access to the slaughterhouse.
The following habits should be avoided by slaughterhouse workers: Walking aimlessly while operations are on Unguarded coughing and sneezing which can spread pathogenic respiratory bacteria: Spitting on hands to enable firm gripping of an axe, panga e.g. while splitting carcass Licking of fingers to pick up items e.g. papers, utensils, paper towels or wrapping papers or to turn over the pages of a book
Cutting of finger nails using teeth or by using slaughter or meat inspection knife Placing the pen, fingers in the mouth Any contact with saliva will transfer salivary bacteria to the hands or fingers Blowing paper bags to open them Shaking of hands in the slaughterhouse Eating, Smoking of cigarettes, chewing miraa in the slaughterhouse
Unnecessary touching of meat and placing of meat on dirty places Chewing sweet-gum Blowing or wiping of nose using bare hands or protective clothing Use of mobile telephones Nose picking and placing fingers in or around the nose, mouth etc removal of ear wax using fingers and then rubbing it on the hands or protective clothing Scratching of head
Brushing of teeth, Urinating in undesignated places within the slaughterhouse environment Changing of clothes near meat Confrontations, fighting or playing in the slaughterhouse Placing meat, knives, sharpening steel in the gumboots Washing the apron and protective clothing on the slaughterhouse floor.
The most significant food borne hazards from fresh meat are bacteria which can cause disease in humans such as Salmonella, Campylobacter and E. coli O157:H7 Some of these pathogens only require a few bacteria to cause food poisoning. These bacteria cannot be detected at postmortem inspection.
Slaughter and dressing operations provide many opportunities for contaminating carcasses with bacteria. The production of a visually clean meat, monitored by visual inspection is an important starting point for meat safety. However, determination of the number and type of bacteria present on the surface of a carcass gives an objective assessment of meat contamination.
Further processing of meat can spread contamination as well as introduce it from equipment, meat handlers or the environment, and poor temperature control can lead to growth of dangerous bacteria. Testing against a microbiological criteria provide a way of measuring how well an operator has controlled the slaughter, dressing and production processes to avoid carcass contamination.
Pathogen control is best achieved by assessing meat for the following: 1. Aerobic plate count (APC)or total viable counts(tvc) 2. Coliform counts 3. Escherichia coli (fecal coliforms) 4. Salmonella species.
APC/TVC is a general measure of the microbiological status of meat. It is a measure of bacteria in the sample that can be harvested by the sampling procedure used and grow in the presence of air on an agar plate. These bacteria include those arising both from animals and from the slaughterhouse or meat processing environment.
APC/TVC include both pathogenic and spoilage bacteria Because APT/TVC includes organisms that are responsible for spoilage of meat, it will also give an indication of the keeping quality of meat. Therefore, meat with high APC (TVC) has poor keeping quality and vice versa.
Coliforms are a group of bacteria that ferment lactose at 37 o C to produce acid and gas. They include organisms in the genera Escherichia, Klebsiella, Enterobacter, Citrobacter Serratia and Hafnia. This group of bacteria are found everywhere in the environment including fecal coliforms that are found in the gastrointestinal tract of animals. The presence of large numbers of coliforms in meat indicates that slaughtering took place under unhygienic conditions.
Fecal coliforms are strains of Escherichia coli that are found in the GIT and are shed in the feces of man and food producing animals. Escherichia col is a rod-shaped member of the coliform group, distinguished from other coliforms by their ability to ferment lactose both at 37 o C and 44 C to produce acid and gas.
When cultured on an Eosin Methylene Blue Agar, a positive result for E. coli is metallic green colonies on a dark purple media. E. coli are almost exclusively of fecal origin and their presence is thus an effective confirmation of fecal contamination. The presence of E. coli in meat is therefore a indicator of fecal contamination. It also indicates the potential risk of occurrence of pathogenic organisms in the meat product.
These are a group of bacteria that include several pathogens of significance in causing food poisoning in humans. They mainly arise from fecal contamination, but can also arise from processing environment.
The results of testing can be used to validate whether the operator s HACCP based procedures are controlling food safety, as well as verify that they are applied correctly. It is assumed that all animals entering the slaughterhouse have the potential to carry pathogenic organisms in or on them, and These microorganisms may be transferred to the carcasses during slaughter and dressing.
Scientific evidence shows that cleanliness of animals at slaughter minimizes the risk of transfer of pathogens from the hide to the carcass. However, a negative microbiological test result doesn t guarantee absence of such pathogens in the carcass as they are usually found in low numbers and in a small area of the carcass. Therefore, control measures that reduce the APC (TVC), coliforms counts, E. coli and Salmonella spp. will reduce the risk of the presence of pathogenic bacteria on meat.
Decision APC/TVC Coliforms /E. coli Unacceptab le > 100,000 cfu /cm 2 Salmonella spp* > 100 cfu/ > 2/ 50 cm 2 carcasses Acceptable 100,000 cfu 100 /cm 2 cfu/cm 2 2/50 carcasses satisfactory 1000 cfu/cm 2 10 cfu/cm 2 < 2/50 carcasses * 5 carcasses are required /sampling session and 1 carcass represent one sample.