Food hygiene • Food is a potential source of infection and is liable to contamination by microorganisms, at any point during its journey from the producer to the consumer. Food hygiene, in its widest sense, implies hygiene in the production, handling, distribution and serving of all types of food. The primary aim of food hygiene is to prevent food poisoning and other food-borne illnesses, which can be grouped under the following headings. • The importance of surveillance of food- borne diseases has been underlined in the WHO Sixth General Program of Work . The most important international program carrying out activities in the field of food hygiene is the Joint FAO/WHO food Standards Program Classification of Food – borne Illnesses Bacterial diseases (infections & Typoid fever, paratyphoid fever, intoxications) Salmonellosis, Staphyloccal intoxication, Cl. perfringens illness Botulism b. cereus Food Poisoning e. coli diarrhoea non-cholera vibrio illness V. parahaemolyticus - infection, streptococcal infection, Shigellosis, Brucellosis Viral diseases Viral hepatitis, Gastroenteritis Parasites Taeniasis, Hydatidosis, Trichinosis, Ascariasis, Amoebiasis, Oxyuriasis Classification of Food – borne Illnesses Chemical poisons Pesticides, heavy metals (arsenic, lead, cadmium, etc.) Food toxins Lathyrism, Epidemic dropsy, Aflatoxins Milk Hygiene • Milk is an efficient vehicle for a great variety of disease agents: The sources of infection or contamination of milk may be (1) The dairy animal (2) human handler or (3) the environment, e.g., contaminated vessels, polluted water, flies, dust, etc. Milkborne Diseases • A joint FAO/WHO Expert Committee on milk hygiene classified milk -born diseases: • 1. Infections of animals that can be transmitted to man: • Primary importance – • Tuberculosis • Brucellosis • Streptococcal infections • Staphylococcal enterotoxin poisoning • Salmonellosis • Q Fever • Milk born diseases • Lesser importance – • Cowpox • Foot and mouth disease • Anthrax • Leptospirosis • Tick-borne encephalitis Infections primary to man tat can be transmitted through milk: • Typhoid and paratyphoid fevers • Shigellosis • Cholera • Enteropathogenic Escherichi coli • Non-diarrhoeal diseases • Streptococcal infections • Staphylococcal food poisoning • Diphtheria • Tuberculosis • Enteroviruses • Viral hepatitis Clean and Safe Milk • The safety and keeping quality of milk are related to its microbial content. The first essential in the production of clean and safe milk, therefore, is a healthy and clean animal. Milk from a healthy udder contains only a few organisms, and these are relatively unimportant. Secondly, the premises where the animal is housed and milked should be sanitary. The milk vessels must be sterile and kept covered. The water supply must be bacteriologicaly safe. • Milk handler must be free from communicable diseases, and before milking they must wash their hands and arms. Where possible, milking machines must be used. Milk should be cooled immediately to below 10°C after it is drawn to retard bacterial growth. In the production of good quality milk, cleanliness of all containers and equipment in which milk is handled is very important. Pasteurization of milk • Pasteurization may be defined as the heating of milk to such temperatures and for such periods of time as are required to destroy any pathogens that may be present while causing minimal changes in the composition, flavor and nutritive value (WHO). There are several methods of pasteurization. • Milk is kept at 63-66°C for at least 30 minutes, and then quickly cooled to 5°C. • “High Temperature and Short Time Method” Milk is rapidly heated to a temperature of nearly 72°C, is held at that temperature for not less than 15 seconds, and is then rapidly cooled to 4°C. This is now the most widely method. Very large quantities of milk per hour can be pasteurized by this method. (3) UHT Method: Also known as “Utra High Temperature Method”. Milk is rapidly heated usually in 2 stages (the second stage usually being under pressure) to between 125°C, for a few seconds only. It is then rapidly cooled and bottled as quickly as possible. MEAT HYGIENE • The term “meat” includes various tissues of animal origin. The diseases which may be transmitted by eating unwholesome meat are: (1) TAPE WORM INFESTATIONS: Tinea soliu, T. saginata, Trichinella spiralis and anthrax, actinomycosis, tuberculosis and food poisoning. Meat Inspection • Animals intended for slaughter are subjected to proper antemortem and postmortem inspection by qualified veterinary staff. The principal causes of antemortem rejection of animals are emaciation, exhaustion, pregnancy, sheep-pox, foot-rot, actinomycosis, brucellosis, febrile conditions, diarrhoea and other diseases of an infectious nature rendering meat unfit for human consumption. The main causes of the postmortem rejection are cysticercus bovis, liver fluke, abscesses, sarcocystis, hydatidosis, septicaemia, parasitic and nodular infections of liver and lungs, tuberculosis, cysticercus cellulosae, etc…(112). The characteristics of good meat are that it should be neither pale pink nor a deep purple tint, firm and elastic to touch, should not be slimy and have an agreeable Slaughter Houses Location: Preferably away from residential areas. Structure: Floors and walls up to 3 feet should be impervious and easy to clean. Disposal of wastes: Blood, offal, etc… should not be discharged into public sewers but should be collected separately. Water Supply: should be independent, adequate and continuous. Examination of animals: Antemortem and postmortem examination to be arranged. Animals or meat found unfit for human consumption should be destroyed or denatured. Miscellaneous: animals other than those to be slaughtered should not be allowed inside the shed. Storage of meat: Meat should be stored in fly-proof and rat-proof rooms; for overnight storage, the temperature of the room shall be maintained below 5°C. 8) Transportation of meat: Meat shall be transported in fly-proof covered vans. Fish • Fish deteriorates or loses its freshness because of autolysis which sets in after death and because of the bacteria with which they become infected. Stale fish should be condemned. The signs of fresh fish: 1) it is in a state of stiffness or rigor mortis, 2) the gills are a bright red and 3) the eyes are clear and prominent EGG • Although the majority of freshly laid eggs are sterile inside, the shells become contaminated by faecal matter from the hen. Microorganisms including pathogenic Salmonella can penetrate a cracked shell and enter the egg(48). FRUITS AND VEGETABLES • Fruits and vegetables constitute another important source for the spread of pathogenic organisms, protozoan and helminthes. These infections are a serious menace to public health where sewage is used for growing vegetables. The vegetables which are consumed raw in the form of salads pose a problem in food sanitation. People should be educated to wash the vegetables before eating then raw. Vegetables which are cooked and eaten are free from this danger. SANITATION OF EATING PLACES • (1) Location: Shall not be near filth or open drain, stable, manure pit and other sources of nuisances. • (2) Floors: To be higher than the adjoining land, made with impervious material and easy to keep clean. ( • 3) Rooms: (a) Rooms where meals are served shall not be less than 100 sq. feet and shall provide accommodation for a maximum of 10 persons. (b) Walls up to 3 feet should be smooth, corners to be rounded; should be impervious and easily washable. ( • c) Lighting and ventilation – ample natural lighting facilities aided by artificial lighting with good circulation of air are necessary. (4) Kitchen: (a) Floor space minimum 60 sq. ft. (b) window opening to be 25 percent of floor area. (c) Floor to be impervious, smooth, easy to keep clean and non-slippery. (d) Doors and windows to be rat-proof, fly-proof, and of the self-closing type. (e) Ventilators 2 percent of the floor area, in addition to smoke pipes. (5) Storage of cooked food: Separate room to be provided. For long storage, control of temperature is necessary. (6) Storage of uncooked foodstuffs. Perishable and non-perishable articles to be kept separately in rat-proof and vermin-proof space; for storage of perishable articles temperature control should be adopted. • ) Furniture: Should be reasonably strong and easy to keep clean and dry. (8) Disposal of refuse: To be collected in covered, impervious bins and disposed of twice a day. (9) Water supply: To be an independent source, adequate, continuous and safe. (10) Washing facilities: To be provided. Cleaning of utensils and crockery to be done in hot water and followed by disinfection. Food Handlers • Food sanitation rests directly upon the state of personal hygiene and habits of the personnel working in the food establishments. Proper handling of foods, utensils and dishes together with emphasis upon the necessity for good personal hygiene are of great importance. The infections which are likely to be transmitted by the food handlers are diarrheas, dysenteries, typhoid and para- typhoid fevers, entero-viruses, viral hepatitis, protozoa cysts, eggs of helminthes, strepto and staphylococcal infections and salmonellosis. • The first essential is to have a complete medical examination carried out of all food handlers at the time of employment. Any person with a history of typhoid fever, diphtheria, chronic dysentery, tuberculosis or any other communicable disease should not be employed. Persons with wounds, otitis media or skin infections should not be permitted to handle food or utensils. The day to day health appraisal of the food handlers is also equally important; those who are ill should be excluded from food handling. It is also important that any illness which occurs in a food handler's family should at once be notified. • Education of food handlers in matters of personal hygiene, food handling, utensils, dishwashing, and insect and rodent control is the best means of promoting food hygiene. Many of the food handlers have little educational background. Certain aspects of personal hygiene are therefore required to be continually impressed upon then: (a) Hands: The hands should be clean at all times. Hands should be scrubbed and washed with soap and water immediately after visiting a lavatory and as often as necessary at other times. Fingernails should be kept trimmed and free from dirt. (b) Hair: Head covering should be provided particularly in the case of females to prevent loose hair obtaining entrance to food-stuffs. (c) Overalls: Clean white overalls should be worn by all food handlers. (d) Habits: Coughing and sneezing in the vicinity of food, licking the fingers before picking up an article of food, smoking on food premises are to be avoided. ADULTERATION OF FOODS • Adulteration of foods consists of a large number of practices - mixing substitution, abstraction, concealing the quality, putting up decomposed foods for sale, misbranding or giving labels and addition of poisons. Some forms of adulteration are injurious to health, eg., adulteration of mustard oil with argemone oil. But for the most part food adulteration has an economic rather than a sanitary significance eg., addition of water to milk. FOOD FORTIFICATION • the process whereby nutrients are added to foods to maintain or improve the quality of the diet of a group, a community or a population‟. FOOD ADDITIVES • The concept of adding “non-food‟ substances to food products is not new. Pickling is an ancient culinary practice aimed at preserving food articles such as mango, lime and amla for fairly long periods by the addition of salt and spices. Modern science of food technology employs more than 3,000 substances – some natural (eg., saffron, turmeric) and others artificial or synthetic (eg., saccharin, sorbic acid) known as „food additives‟. Majority of the processed foods such as bread, biscuits, cakes, sweets, confectionary, jams, jellies, soft drinks, ketchup, all contain food additives. FOOD ADDITIVES • Food additives are defined as non-nutritious substances which are added intentionally to food, generally in small quantity, to improve its appearance, flavour, texture or storage properties(116). The definition also includes animal food adjuncts which may result in residues in human food and components of packing materials which may find their way into food(117). • The food additives may be classified as colouring agents (eg., saffron, turmeric), flavouring agents (eg., vanilla essence), sweeteners (eg., saccarin), preservatives (eg., sorbic acid, sodium benzoate), bleaching agents (eg., chlorine) acidity imparting agents (eg., citric acid acetic acid), etc..(115). Uncontrolled or indiscriminate use of food additives may pose health hazards among consumers.