Introduction To Meat Hygiene

Module 2 INTRODUCTION TO MEAT HYGIENE

Topic 1 Definition of Meat and Meat Safety

MEAT  Is defined as all parts of an animal that are intended for, or have been judged as safe and suitable for human consumption.  Most often, this means the skeletal muscle and associated fat, but it may also describe other edible tissues such as organs, livers, skin, brains, bone marrow, kidneys, or lungs.

Is concerned on clean or healthy practices or thinking.

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Refers to all conditions and measures necessary to ensure the safety and suitability of meat at all stages of the food chain. Is therefore can be simply define as cleanliness on meat preparation.

MEAT SAFETY Is the assurance that meat will not cause harm to the consumer when it is prepared and/or eaten. Appropriate application of measures to protect public health, and achievement of any quantitative outcomes for hazard control that may be required at every stage along the food chain from farm to plate.

Topic 2 THE IMPORTANCE OF MEAT SAFETY AND QUALITY

 Reduces

the risk of food-borne diseases and food poisoning.

 Handling

meat safely also helps to preserve its appearance, flavor, texture, consistency, and nutritional value.

Topic 3 TYPES OF CONTAMINANTS

Contaminants are Classified into Three Categories:  BIOLOGICAL  CHEMICAL  PHYSICAL

A. BIOLOGICAL CONTAMINANTS 1. BACTERIA  Bacteria are ubiquitous in nature. Some are beneficial (e.g., those used in making fermented foods) and some can cause food-borne illnesses and food poisoning. e.g. Salmonella, E. coli, Staphylococcus  Some bacteria, especially those that can make spores, can survive on produce or food contact surfaces for a long period of time. The spores will germinate when the environment is suitable for growth and they will multiply again. e.g. Clostridium

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Temperature (warmth) – bacteria multiply quickly at 5°C and 63°C known as “danger zone”. Time (for reproduction) – under ideal conditions, 1 bacterium can multiply by dividing into 2 every 20 min. Food (high risk meat/food) – bacteria prefer food that are high in protein e.g. meat, dairy products, eggs. Water (moisture) – bacteria need moisture to stay alive & when water is added to them, spores will germinate & bacteria will start growing. Air (oxygen) – bacteria need air to survive (though there are some that do not need free oxygen). This explains the reason for some food being able to keep longer when vacuum packed. pH (acidity) – most bacteria prefer food to be in the range of neutral pH, i.e. 7. High acidity can kill them.

Staphylococcus aureus

Mycobacterium tuberculosis

E.coli

2. VIRUSES Viruses multiply in the living cell only.  Unlike bacteria, viruses cannot reproduce in food. However, some viruses may survive cooking or freezing. The more serious food-borne viral infection is caused by Hepatitis A virus, which is transmitted by an infected person who frequently handles meat or food that requires no further heating, such as salads or herbs (e.g., green onions), and has not washed his or her hands after using the toilet.

Rotavirus

Influenza virus

FMD virus

3. PARASITES  Parasites are microorganisms that need a host to survive.

 These parasites can also be transmitted via personto-person contact if good personal hygiene practices are not followed.  These microscopic parasites are also associated with poor water quality.  The best known parasite is Trichinella spiralis, a roundworm found in pigs and certain other game animals. If not killed by thorough cooking or freezing for specified time periods, its larvae can cause trichinosis, a disease that causes painful abdominal and muscular cramps.

Taenia saginata

(Beef tapeworm)

Fasciola hepatica (liver fluke)

Teania solium

(pork tapeworm)

4. FUNGI, MOLDS, and YEAST  Fungi are microorganisms that range from singlecelled plants to mushrooms. It can be found in air, soil, and water  Mold cells are usually microscopic, but mold colonies may be seen as fuzzy growth on food. The main damage caused by molds is spoilage, but some molds also produce toxins that can cause illness, infections, and allergic reactions Yeasts spoil products by slowly eating the food. Contamination appears as bubbles, an alcoholic smell or taste, pink discoloration, or slime.

Fungi (fungal spores)

Mold Cells (Aspergillus)

Yeast (Candida albicans)

B. CHEMICAL CONTAMINANTS  Chemical contamination can occur in any stages of slaughtering/processing operation or storage.  Any chemicals used in the operation can potentially become chemical contaminants if they are improperly used.  Include pesticides, cleaning & sanitizing compounds, dangerous metal products (e.g. lead, copper, paint), additives and preservatives, and any foreign chemical that comes in contact with meat, equipment and personnel.

C. PHYSICAL CONTAMINANTS  Any foreign objects that are accidentally or intentionally mixed in with foods or produce which may cause illness or injury to an individual.  May be brought into meat premises with the raw materials or introduced during storage, preparation, service or display.  Physical contaminants include glass, metal fragments (e.g., nails, screws, staples), packaging materials, fingernails, nail polish, hair, jewelries, feathers, droppings , dead insects, insect wings & eggs, candy wrappers & cigarette butts, flaking paint or rust, wood splinters.

Topic 4 CROSS CONTAMINATION

CROSS-CONTAMINATION Refers to the transfer of harmful substances or disease-causing microorganisms to meat/food by hands, food-contact surfaces, or cleaning cloths that touch raw food, are not cleaned and sanitized, and then touched ready-to-eat food.

 How does bacterial contamination of meat occur ?  In live animal, the muscle meat is virtually sterile. However other parts of the animal such as skins, hooves and intestines contain enormous numbers of bacteria.  Depending on the slaughter hygiene, these bacteria find their way to the carcass or “contaminate” the meat during slaughterhouse operations.

 Skinning, scalding, evisceration, dressing and carcass transport are common contamination points.  Most bacteria reach the carcass via butchers’ hands, tools, contact with equipment or through water, air, etc.

Bacterial contamination is ongoing during the operations following the slaughter process such as meat cutting and meat processing.

Microbial Contamination in the Meat Processing Chain

Topic 5 SOURCE, GROWTH and KILLING of MICROORGANISMS

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WATER AIR EQUIPMENT AND FACILITIES PESTS PERSONNEL (MEAT HANDLERS)

A. Source and Growth  Most microorganisms live freely in the environment without causing harm to humans or other organisms; in fact most of them are beneficial in a variety of ways.  For these reasons, humans seek to control only certain types of microorganisms and under relatively few specific circumstances.  Control is exerted over microorganisms associated with food materials, so that foods can be stored and made available for human consumption without being consumed by microorganisms first.

1. Contamination by Water  Besides its use as an ingredient in food preparation, water is used in several food processes: washing, fluid transport, cooling, cleaning and disinfection, etc.  When the water is of poor microbiological quality, it is an important source of food contamination  Water cooling, for example, is responsible for most of the contamination of sterilized cans, but badly crimped

2. Contamination by Air  An important source of contamination of foods that are handled in the open air.  Air filtration and work under controlled atmosphere, reduces the contamination of food by microorganisms in the air.

3. Contamination by machinery and utensils  Machinery (grinders, mixers, etc.) and utensils (knives, etc.) are also an important source of food contamination during preparation.  Germs carried by the equipment and utensils

are generally the various contaminants of food. These bacteria multiply in the presence of food debris that remain adhered to the machines.

4. Contamination by Meat Handlers Microorganisms transmitted by meat handlers are those that exist naturally in the human body or which may come from contaminated raw materials that they handle.

 Also, it is important to note that meat handlers may be an important source of fecal contaminants (Escherichia, Staphylococcus)  To control this type of contamination of food, it is essential that they comply with good hygiene practices.

 Pests

could harbor microorganisms and parasites both inside and outside their bodies, due to the dirty places they visit. They could defecate or urinate onto food or dirty work surfaces.  Their presence in the meat establishment certainly increase the risk of contamination and food poisoning.

 Microorganisms Naturally Present in Food 1. Surface microorganisms in food  Microorganisms found on the surface of foods are those usually encountered in soil, air and water. These are bacteria (Micrococcus, Enterobacter,etc), molds (Aspergillus, Penicillium, Fusarium, etc) and yeasts (Saccharomyces, etc).

2. Microorganisms in the digestive tract of animals  Microorganisms naturally present in the digestive system are usually bacteria such as Enterobacteria (Salmonella, Escherichia, Shigella ,etc), Enterococci (Streptococcus, etc) and other (Staphylococcus, Lactobacillus, etc)  Molds are poorly represented among the yeasts, the genus Candida is the most common  The viscera are the main sources of contamination of meat and fish. The contamination of muscle tissue is by migration of microorganisms through the lymphatic system and is facilitated by cutting and washing of carcasses.

B. PHYSICAL FACTORS EFFECTIVE IN THE CONTROL OF MICROORGANISMS 1. Temperature a.Freezing – to inhibit the growth of microorganisms b. Pasteurization – application of heat at a specified temp for a specific time so that spoilage due to microorganisms is prevented or at least slowed. c. Tyndallization – subjecting liquids to alternate periods of boiling and cooling extended over 3 days. d. Autoclaving (moist heat) – application of heat and pressure simultaneously which effectively kill all types of cellular pathogens within minutes. e. Radiation – Ultraviolet (UV) radiation is effective but is limited to surface sterilization because it does not penetrate glass, dirt films, water other substances. Ionizing radiation (x rays, gamma rays, etc)on the other hand is effective and penetrates the material. Currently used to sterilize such heat sensitive pharmaceuticals as vitamins, hormones and antibiotics.

1. Phenolics

– laboratory & hospital disinfectants; act by denaturing proteins 2. Alcohol – widely used disinfectants & antiseptics but will not kill endospores 3. Halogens – widely used; e.g. iodine and chlorine (cheapest and readily available) 4. Heavy metals – effective but usually toxic 5. Aldehydes – can be used as chemical sterilants, but may irritate the skin. 6. Quarternary ammonium compounds 7. Skin antiseptic 8. Sterilizing gases (e.g. ethylene oxide)

....End of Module 2