Food hygiene (Definition, types, causes)

Food hygine

1. Food hygiene

2. Definition Hygiene in the P roduction , H andling , D istribution and S erving of all types of food .

3. Need 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 . Access to sufficient amounts of safe and nutritious food is key to sustaining life and promoting good health . Food safety, nutrition and food security are closely linked.

4. Unsafe food creates a vicious cycle of disease and malnutrition, particularly affecting infants, young children, elderly and the sick. In addition to contributing to food and nutrition security, a safe food supply also supports national economies, trade and tourism, stimulating sustainable development. The globalization of food trade, a growing world population, climate change and rapidly changing food systems have an impact on the safety of food. WHO aims to enhance at a global and country-level the capacity to prevent, detect and respond to public health threats associated with unsafe food.

5. Burden of food borne illnesses Unsafe food containing harmful bacteria, viruses, parasites or chemical substances can cause more than 200 different diseases – ranging from diarrhoea to cancers. Around the world, an estimated 600 million – almost 1 in 10 people – fall ill after eating contaminated food each year, resulting in 420 000 deaths and the loss of 33 million healthy life years (DALYs ).

6. The burden has often been underestimated due to underreporting and difficulty to establish causal relationships between food contamination and resulting illness or death. The 2015 WHO report on the estimates of the global burden of foodborne diseases presented the first-ever estimates of disease burden caused by 31 foodborne agents (bacteria, viruses, parasites, toxins and chemicals) at global and regional level . The 2018 World Bank report on the economic burden of the foodborne diseases indicated that the total productivity loss associated with foodborne disease in low- and middle-income countries was estimated to cost US$ 95.2 billion per year, and the annual cost of treating foodborne illnesses is estimated at US$ 15 billion.

7. FOOD-BORNE DISEASES D efined as : "A disease, usually either infectious or toxic in nature, caused by agents that enter the body through the ingestion of food .“ With the increase in urbanization, industrialization, tourism and mass catering systems, food-borne diseases are on the increase throughout the world.

8. Food-borne diseases may be classified as : A . Food-borne intoxications 1. Due to naturally occurring toxins in some foods : a. Lathyrism (beta oxalyl amino-alanine) b. Endemic ascitis (Pyrrolizidine alkaloids ). 2. Due to toxins produced by certain bacteria : a. Botulism b. Staphyloccus poisons

9. 3. Due to toxins produced by some fungi : a . Aflatoxin b. Ergot c. Fusarium toxins 4 . Food-borne chemical poisoning : a. Heavy metals, e.g., mercury (usually in fish ), cadmium (in certain shellfish) and lead (in canned food) b. Oils, petroleum derivatives and solvents (e.g ., Trycresyn phosphate or TCP) c. Migrant chemicals from package materials d. Asbestos e. Pesticide residues (DDT, BHC)

10. B. Food-borne infections ( 1) Bacterial diseases - Typhoid fever, Paratyphoid fever, Salmonellosis , Staphylococcal intoxication , CJ.perfringens illness, Botulism , B.cereus Food Poisoning, E.coli diarrhoea, Non-cholera vibrio illness,V . parahaemolyticus infection , Streptococcal infection, Shigellosis, Brucellosis (2) Viral diseases- hepatitis A and E, Norovirus Gastroenteritis . (3) Parasites- Taeniasis Hydatidosis , Trichinosis, Ascariasis , Amoebiasis ,

11. Aim of food hygiene The primary aim of food hygiene is to prevent food poisoning and other food-borne illnesses.

12. Food hygiene can be grouped under the following headings : A. MILK HYGIENE Source of Infection T he dairy animal ( 2) Human handler or ( 3) The environment , e.g., contaminated vessels, polluted water, flies , dust, etc.

13. Milkborne diseases’ classification ( 1) Infections of animals that can be transmitted to man: Primary importance: Tuberculosis, Brucellosis, Streptococcal infections, Staphylococcal enterotoxin poisoning, Salmonellosis, Q fever. Lesser importance : Cow-pox, Foot and mouth disease, Anthrax, Leptospirosis, Tick-borne encephalitis.

14. (2) Infections primary to man that can be transmitted through milk : · Typhoid and paratyphoid fevers, Shigellosis, Cholera, Enteropathogenic Escherichiacoli (EEC ) Non-diarrhoeal diseases- Streptococcal infections, Staphylococcal food poisoning, Diphtheria, Tuberculosis, Enteroviruses, Viral hepatitis

15. 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. 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 bacteriologically 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 deg.C after it is drawn to retard bacterial growth .

16. Tests for microbiological quality of milk Methylene blue reduction test : It is an indirect method for detection of microorganisms in milk. The test is carried out on the milk accepted for pasteurization. It is based on the observation that bacteriae growing in milk bring about a decrease in the colour imparted to milk.

17. In conducting the test, definite quantities of methylene blue are added to 10 ml of milk and the sample is held at a uniform temperature of 37 deg C until the blue colour has disappeared. The milk which remains blue the longest is considered to be of the best quality and a scale of grading different milk samples, on the basis of the time required to reduce a definite quantity of methylene blue has been worked out. The test thus serves as confirmation of heavy contamination and compared with direct counts of bacteriae , it saves time and money.

18. Pasteurization of milk D efined 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, flavour and nutritive value. There are several methods of pasteurization.

19. Holder (Vat) method : In this process, milk is kept at 63- 66 deg C for at least 30 minutes, and then quickly cooled to 5 deg C . R ecommended for small and rural communities . (2) HTST method : 'High Temperature and Short Time Method" . Milk is rapidly heated to a temperature of nearly 72 deg C , is held at that temperature for not less than 15 seconds , and is then rapidly cooled to 4 deg C . This is now the most widely used method. Very large quantities of milk per hour can be pasteurized by this method. ( 3) UHT Method : ultra-high temperature method ." Milk is rapidly heated usually in 2 stages ( the second stage usually being under pressure) to 125 deg C for a few seconds only. It is then rapidly cooled and bottled as quickly as possible .

20. Pasteurization kills nearly 90 per cent of the bacteria in milk including the more heat-resistant tubercle bacillus and the Q fever organisms. But it will not kill thermoduric bacteria nor the bacterial spores. Therefore, despite pasteurization, with subsequent rise in temperature , the bacteria are bound to multiply. In order to check the growth of microorganisms, pasteurized milk is rapidly cooled to 4 deg C. It should be kept cold until it reaches the consumer. Hygienically produced pasteurized milk has a keeping quality of not more than 8 to 12 hours at 18 deg C.

21. Tests of pasteurized milk Phosphatase test : T o check the efficiency of pasteurization. R aw milk contains an enzyme called phosphatase which is destroyed on heating at a temperature which corresponds closely with the standard time and temperature required for pasteurization . At 60 deg C for 30 minutes phosphatase is completely destroyed. Consequently , the test is used to detect inadequate pasteurization or the addition of raw milk .

22. (2) Standard plate count : Most countries in the West enforce a limit of 30,000 bacterial count per ml of pasteurized milk. ( 3) Coliform count : The standard in most countries is that coliforms be absent in 1 ml of milk.

23. MEAT HYGIENE The term "meat" includes various tissues of animal origin . The diseases which may be transmitted by eating unwholesome meat are: ( 1) TAPEWORM INFESTATIONS : ( 2) BACTERIAL INFECTIONS anthrax, actinomycosis , tuberculosis and food poisoning .

24. Meat inspection Animals intended for slaughter are subjected to proper ante mortem and post mortem 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 post mortem rejection are cysticercus bovis , liver fluke , abscesses, sarcocystis , hydatidosis , septicaemia , parasitic and nodular infections of liver and lungs , tuberculosis, cysticercus cellulosae , etc . 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 odour .

25. Slaughter houses The following minimum standards for slaughter houses have been suggested under the Model Public Health Act ( 1955) in India (1) Location : Preferably away from residential areas . (2) Structure : Floors and walls upto 3 feet should be impervious and easy to clean. ( 3) Disposal of wastes : Blood, offal , etc. should not be discharged into public sewers but should be collected separately.

26. (4) Water supply : should be independent , adequate and continuous. ( 5) Examination of animals : Ante mortem and post mortem examination to be arranged . ( 6) 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 deg C. ( 7) Transportation of meat : Meat shall be transported in fly-proof covered vans. (8) Miscellaneous : Animals other than those to be slaughtered should not be allowed inside the shed .

27. Sanitation of eating places The following minimum standards have been suggested for Restaurants and Eating Houses in India under the Model Public Health Act (1955 ). Location : Shall not be near any accumulation of 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 .

28. (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 per cent of floor area. (c) Floor to be impervious, smooth, easy to keep clean and non-slippery. (d) Doors and windows to be ratproof , fly-proof , and of the self- closing type. (e) Ventilators 2 per cent 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 .

29. (6) Storage of uncooked foodstuffs : Perishable and nonperishable articles to be kept separately, in rat- proof and vermin-proof space; for storage of perishable articles temperature control should be adopted. ( 7) 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 off 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 .

30. Food handlers The infections which are likely to be transmitted by the food handlers are diarrhoeas, dysenteries, typhoid and paratyphoid fevers ,enteroviruses , viral hepatitis, protozoal cysts, eggs of helminths , strepto and staphylococcal infections, and salmonellosis .

31. The first essential is to have 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 a lso 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 .

32. Education of food handlers in matters of personal hygiene , food handling, utensils, dish washing, and insect and rodent control is the best means of promoting food hygiene . Certain aspects of personal hygiene are therefore required to be continually impressed upon them: (a) Hands : The hands should be clean at all times. Hands should be scrubbed and washed with soap immediately after visiting a lavatory and as often as necessary at other times. Finger nails should be kept trimmed and free from dirt. (b) Hair: Head coverings should be provided, particularly in the case of females to prevent loose hair entering the 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.

33. International Food Standards The  C O D E X  A L I M E N T A R I U S international food standards, guidelines and codes of practice contribute to the safety, quality and fairness of this international food trade. Consumers can trust the safety and quality of the food products they buy and importers can trust that the food they ordered will be in accordance with their specifications . Veterinary drugs, pesticides, food additives and contaminants are some of the issues discussed in Codex meetings. While being recommendations for voluntary application by members, Codex standards serve in many cases as a basis for national legislation. Removing Barriers to Trade International food trade is a 2000 billion dollar a year industry, with billions of tonnes of food produced, marketed and transported.

34. Nature of Codex Standards Codex standards and related texts are not a substitute for, or alternative to national legislation . Codex standards and related texts contain requirements for food aimed at ensuring for the consumer a safe, wholesome food product free from adulteration, correctly labelled and presented .

35. What is 'One Health'? 'One Health' is an approach to designing and implementing programmes , policies, legislation and research in which multiple sectors communicate and work together to achieve better public health outcomes. The areas of work in which a One Health approach is particularly relevant include food safety, the control of zoonoses , and combatting antibiotic resistance.

36. The evolving world and food safety Safe food supplies support national economies, trade and tourism, contribute to food and nutrition security, and underpin sustainable development. Urbanization and changes in consumer habits, including travel, have increased the number of people buying and eating food prepared in public places. Globalization - growing consumer demand for a wider variety of foods, resulting in an increasingly complex and longer global food chain. As the world’s population grows -

37. Climate change is also predicted to impact food safety. These challenges put greater responsibility on food producers and handlers to ensure food safety. Local incidents can quickly evolve into international emergencies due to the speed and range of product distribution. Serious foodborne disease outbreaks have occurred on every continent in the past decade, often amplified by globalized trade .

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