Food Safety Definition Factors affecting it - PowerPoint Presentation

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Food Safety

Definition

Factors affecting it

Types of hazards

Impact on health

Control measures

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Definition

Food is one of the three essentials for maintenance of life.

The first objective of any country is for increased food supply in sufficient amount and of the right nutritional content to meet the needs of ever increasing population.

Such food has to be safe which implies that its consumption should not give rise to

any food borne

diseases whether from infection, intoxication, contamination, adulteration or other sources.

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Factors affecting food safety

The main factors affecting food safety are-

Bacterial contamination

Environmental contamination

Natural contamination; and

Use of additives and pesticides etc.

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1. Bacterial Contamination

Importance of

foodborne

diseases due to bacterial contamination is immense. Hence, prevention of them due to bacterial contamination is needful in this respect.

2.Environmental contamination

It includes those people as careless food handler, human carrier of disease who prepare food either at home or in a factory, kitchen of a restaurant, hotel, canteen, school etc. will put the health at risk of them.

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3. Natural contamination

It includes mishandling of food, least protection during food preparation, contamination during food display and service and food transportation.

4. Use of additives and pesticides

Chemicals which can also pose a health hazard is called ‘food additives’ should be used under strict control. Some of the food additives are preservatives, antioxidants, emulsifiers and

stabilisers

etc.

Use of insecticides and pesticides to protect foods from insects, pests, moulds etc. is another necessary evil.

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Few aspects of

food safety

Safety of raw food material

To control food borne illness and food spoilage which may result from improperly handled or transported food, people should be concerned about sources of food they use.

Protection of food after procurement

To protect the food from being contaminated at all times within the establishments and also during transportation.

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Following measures must be taken

Food must be stored in a food grade plastic container.

Food must be stored in such a location that does not result in a high risk of contamination.

Bulk food such as cooking oil, salt, sugar and flour in which they are kept should be properly labeled.

Food must be stored at proper storage temperature.

Refrigeration facilities to control growth of microorganisms should be maintained.

Hot storage facilities for hazardous food should be maintained.

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Food preparation

Personal hygiene, cooking, reheating and minimal handling of food during food preparation.

Food display and service

Contamination of and microbial growth in food during food display and service results from contaminated equipment, improper control of food temperatures or insanitary display.

Food transportation

Safe transportation of prepared food assures greater importance.

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Personal hygiene and health requirement

Diseases and infections may be transmitted by infected food handlers to the consumers.

Equipment and utensils

Food poisoning may result from acidic foods or drinks which has been in contact with such metals as cadmium, lead or zinc.

Sanitary facilities and controls

Potable water, proper disposal of sewage, plumbing system so that there is no cross contamination between potable water supply and non-potable water., toilet facilities and proper disposal of garbage and refuse.

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Control of insect and pest

Insect and pest cause a big problem in food service establishments. The flies and cockroaches are the important carriers of food borne diseases. Among pests, rats and mice spread food borne diseases.

Hazardous substances in food

Microbial contaminants

Environmental contamination

Natural toxins

Agricultural residues

Intentional food additives

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Microbial contaminants caused by:

Pathogenic bacteria

Food poisoning

- outbreaks of acute gastroenteritis caused by microbial pathogens in the form of

Food borne intoxication-

where microbes in food produce a toxin that produces the symptom and

Food borne infection-

where the symptoms are caused by the activity of live bacterial cells multiplying in the gastrointestinal system.

Factors contributing to food poisoning-

Improper cooling of food

Lapses of 12 hours or more between preparing and eating

Contamination by food handlers

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Contaminated raw foods or ingredients

New and emerging pathogens

Changes in the food supply including more intensive animal husbandry, longer shelf-life of fresh chilled products.

Ageing populations

Greater proportion of food eaten away from home

Mycotoxins

Aflatoxins

from

Aspergillus

fungus are highly toxic and carcinogenic causing liver damage. Such contamination can occur when environmental conditions are suitable for mould growth.

Patulin

by the mould

Penicillium

caviforme

may contain in apple juices and some baked goods with fruit.

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Fumonisins

from the

fusarium

fungus is associated with maize.

New

foodborne

diseases

Camphylobacter

jejuni

found in the flesh of cattle, sheep, pigs, poultry and raw meat is one of the important causes of gastroenteritis.

Listeria

monocytogenes

grows at refrigeration temperatures (<0⁰C) can cause abortions as well as death in the elderly and those with compromised immune systems such as AIDS.

It is also found in contaminated milk, soft cheese, undercooked chicken and

preprepared

chilled food.

Escherichia coli present in raw and undercooked

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hamburger can damage the cells of the colon leading to bloody

diarrhoea

and abdominal cramps.

Salmonella

typhimurium

can survive at low pH

Norwalk virus found in the

faeces

of humans is caused by poor personal hygiene among infected food handlers. As it is a virus, it does not reproduce in food but remains active until the food is eaten.

Mad cow disease or BSE (bovine

spongioform

encephalopathy) is a slowly progressive and ultimately fatal neurological disorder of adult cattle that results from infection by an unique transmission agent called

prion

(modified forms of normal cell-surface protein).

Same infective agent is responsible for variant

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Creutzfeldt-Jakob disease (

vCJD

) a fatal disease of humans caused by beef meat infected with BSE. Feeding of meat and

bonemeal

to any farmed livestock is also banned as it may contain BSE.

2.

Environmental contamination

caused by:

Heavy metals and minerals

Selenium

- Excessive selenium intake has been associated with gastrointestinal disturbances and skin discoloration with brittle hair, skin lesions and neurological disturbances.

Mercury

- Fish can contain 10-500mg/kg of organic mercury or even higher when mercury wastes are released into lake waters. Maximum permitted levels

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of mercury in fish 0.4-1.0 mg/kg. Mercury poisoning in fish occurred in

Minamata

Bay in Japan. In Iraq mercury intoxication occurred in wheat bread when they are treated with mercury based pesticides.

Cadmium

- Chronic exposure at excessive levels can lead to irreversible kidney failure. The average food-based cadmium intake is approx. 10-50µg/day.

Criminal adulteration

Milk is diluted with water, cocoa with sawdust, some operators preserved milk with formaldehyde and butter with borax.

Packaging migration

Lead

used in the solder of metal cans was significant

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source of contamination of infant formulae.

Polyvinyl chloride (PVC)

, the parent compound for many polymers used in food packaging materials, has been detected in a variety of products stored in PVC containers.

Industrial pollution

Polychlorinated biphenyls (PCBs)

a highly stable derivatives of biphenyl used in plastics, paints and lubricants, their stability and solubility result in accumulation in fatty tissue and widely found in seafood.

Radioactive contamination

Strontium-90 and caesium-137

, two dangerous

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radioisotope with half-lives of 28 and 30 years.

Strontium is absorbed and metabolized like calcium and stored in bones. It is particularly dangerous for infants and children.

Accidental exposure of radioactive contamination may occur and lead to dangerous food contamination over widespread areas.

Changes during cooking or processing

Polycyclic aromatic hydrocarbons

are carcinogens produced by burning of fat during roasting and frying when localized areas of food are subjected to temperatures that lead to carbonization.

Heterocyclic amines

produced from amino acids are too carcinogens.

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Char-broiling or barbecuing

lead to carcinogen formation.

Acrylamide

found in starch containing foods cooked at high temperatures is known to be toxic to the nervous system and may cause genetic damage.

Irradiation

method can be used to sterilize foods, control microbial spoilage, eradicate insect infestations and inhibit undesired sprouting but still opposition from consumers that the process producing toxic chemicals in food.

3. Natural toxins

Inherent natural toxins

like

cyanogenic

glycosides in plants such as almond kernels, cassava and sorghum;

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Alkaloids in herbal teas;

lathyrus

toxin in chickpeas; puffer fish in Japan contains a fatal neurotoxin called

tetrodotoxin

produce a tingling sensation.

Abnormal conditions of the animal or plant used for food

like

ciguatera poisoning

caused by eating contaminated fish. Symptoms include gastrointestinal disorders, neurological problems and in severe cases death.

Paralytic shell fish poisoning

Symptoms include numbness of lips, ascending paralysis and even death within 24 hours

Glykoalkaloids

in potatoes

Solanin

, a heat stable

glykoalkaloids

found in green

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parts of potato are toxic above concentration of 20mg/dl.

Glykoalkaloids

possess

anticholinesterase

activity producing gastrointestinal and neurological disorders and even death.

Enzyme inhibitors

Protease inhibitors

present in many legume species and

trypsin

inhibitors are found in oats, maize,

brussel

sprouts, onion and beetroot. Feeding raw legumes to animals can result in pancreatic enlargement.

Antivitamins

Avidin

present in raw egg white is the biotin binding protein, makes vitamin biotin

unavaiable

to the body.

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2. Other

antivitamins

are the pyridoxine antagonist amino-D-

proline

in flax seeds,

antithiamin

compound in

cafeic

acid and

tocopherol

oxidase

in raw

soyabean

.

Mineral binding agents

Goitrogens

:

glucosinolate

and

thiocyanate

compounds found in foods interfere with normal

utilisation

of iodine by the thyroid gland resulting in

goitre

. Present in cruciferous vegetables as cabbage, broccoli, etc.

Phytate

: found in

wholemeal

cereals bind with minerals and make them less available to the body for absorption.

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Oxalate

: Spinach, beetroot, tea contain high levels of oxalates. Bind with calcium to form insoluble complex.

Tannins (

polyphenols

)

: Present in tea, coffee, cocoa and broad beans. Interfere with iron absorption.

Agricultural residues

Pesticides: DDT

are highly toxic to insects, stable compound and persist in soils, stored in the fat tissue of animals, possess carcinogenic activity.

Fungicides and herbicides:

very selective toxicity to their target plants, possess very little hazard to humans.

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c)

Hormones

: Bovine

somatotrophin

(BST) to improve yields of milk and meat and to reduce the percentage of carcass fat.

5.

Intentional food additives

These are consumed to an acceptable daily intake, a safety factor for humans.

Overconsumption may increases the chances of developing cancer.

Artificial sweeteners

Saccharin

Oldest artificial sweeteners

At lower doses as 1% no adverse effects are found.

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Cyclamate

, a permitted sweetener, used widely in several countries.

Aspartame

Risk for people with

phenylketonuria

.

Extremely safe sweetener that is digested like any other protein.

b)

Preservaties

Sodium nitrite

Nitrites react with secondary amines in food, many of which are carcinogenic.

Recently, manufacturers worked to reduce the level of nitrite used in cured meats.

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Sulphur

dioxide

Sulphur

dioxide and its salts used as inhibitors of

enzymic

browning, dough conditioners, antimicrobials and antioxidants.

1-2% of asthmatics are sensitive to

sulphites

.

c)

Colours

and

flavours

Amaranth (Red no.2)

High dosage results in a statistically significant increase in malignant

tumours

.

Tartrazine

Though permitted but its presence has to be declared in level so that sensitive individuals can avoid it.

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Impact on health

Biological contamination

1.Pathogenic bacteria

a.Gastroenteritis

b.Foodborne

intoxication

c.Foodborne

infection

2.Mycotoxins

a.Carcinogenic

3.New

foodborne

diseases

a.Gastroenteritis

(

camphylobacter

jejuni

)

b.Abortions

and death (

Listeria

monocytogenes

)

c.Damage

cells of the colon, bloody

diarrhoea

and abdominal cramps (

E.coli

)

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d.Nausea

, vomiting,

diarrhoea

, abdominal pain, fever (Norwalk virus)

e.Mental

changes such as memory loss, slurred speech, muscle twitching, confusion, fits and unconsciousness (variant Creutzfeldt-Jakob disease)

Chemical contamination

1.Heavy metals and minerals

a. Selenium: gastrointestinal disturbances and skin discoloration, brittle hair, skin lesions and neurological disturbances.

b. Cadmium: irreversible kidney failure.

2. Changes during cooking or processing

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Acrylamide

: neurological damage, genetic damage.

3. Pesticides:

DDT:carcinogenic

4. Intentional food additives:

Sulphur

dioxide: those sensitive may cause allergy.

Physical contaminatio

n

1. Inherent natural toxin: Puffer fish: fatal neurotoxin as

tetrodotoxin

, produce tingling sensation.

2. Abnormal conditions of the animal or plant used for food: ciguatera poisoning: gastrointestinal disorders, neurological problems and in severe cases death.

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3. Paralytic shell fish poisoning: numbness of the lips and fingertips, ascending paralysis can lead to death within 24 hours.

4.Glycoalkaloids in potatoes:

Solanin

: gastrointestinal and neurological disorders and deaths.

5. Enzyme inhibitors: inhibits enzyme, affects digestion.

6.

Antivitamins

: vitamin deficiency

7

.

Mineral binding agents:

Goitrogens

:

Goitre

Phytate

, Oxalate: mineral deficiency

Tannins: low iron status

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Control measures

Proper cooling of food

Consumption of food within 12 hours of preparation.

Sanitation and hygiene to be maintained by food handlers.

Fresh raw foods and ingredients without contamination

Clean and sanitized work place area.

Formal training of all food handlers

Development of food safety plans

Controls on waste disposal

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In case of cadmium, developing new crops that accumulate less cadmium.

Maintenance of standards in food industry.

Control illegal adulteration.

Introduction of non soldered cans to avoid lead contamination.

Avoidance of cooking of food at high temperature.

Avoiding irradiated foods.

Avoidance, removal and detoxification are the three ways to be followed to protect from harmful effects of food.

Inactivation of enzyme inhibitors by cooking.

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Inactivation of

antivitamins

by cooking.

Inactivation of

goitrogens

by blanching and avoiding.

Avoiding pesticides by thorough washing.

Usage of food additives by manufacturers only

upto

the level of acceptable daily intake.

Proper reheating

of food