Title: Food hygiene
1Food hygiene
2- 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.
3- 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
4Classification of Food borne Illnesses
Bacterial diseases (infections intoxications) Typoid fever, paratyphoid fever, 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
5Classification of Food borne Illnesses
Chemical poisons Pesticides, heavy metals (arsenic, lead, cadmium, etc.)
Food toxins Lathyrism, Epidemic dropsy, Aflatoxins
6Milk 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.
7Milkborne 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
-
8Milk born diseases
- Lesser importance
- Cowpox
- Foot and mouth disease
- Anthrax
- Leptospirosis
- Tick-borne encephalitis
9- 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
10Clean 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.
11- 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 10C 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.
12Pasteurization 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 63-66C for at least 30 minutes,
and then quickly cooled to 5C.
13- High Temperature and Short Time Method Milk is
rapidly heated to a temperature of nearly 72C,
is held at that temperature for not less than 15
seconds, and is then rapidly cooled to 4C. 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 125C,
for a few seconds only. It is then rapidly
cooled and bottled as quickly as possible.
14MEAT 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.
15Meat 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
16Slaughter 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 5C. 8) Transportation of
meat Meat shall be transported in fly-proof
covered vans.
17Fish
- 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
18EGG
- 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).
19FRUITS 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.
20SANITATION 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. (
21- 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.
22- ) 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.
23Food 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.
24- 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.
25- 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.
26ADULTERATION 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.
27FOOD 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.
28FOOD 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.
29FOOD 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.
30(No Transcript)
31(No Transcript)