Causes of Food Contamination
Food contamination may occur at any point of time, right from it is delivered in the kitchen, till it is consumed by the guests. It is said that poor hygiene is costly as it may cause contamination to the food resulting FOOD POISIONING, which will bring a bad name for the organization and people will start avoiding the outlet.
Premises maintaining good hygienic conditions attract the guests and they feel the environment and place is safe to eat thus contributing to good business. Food poisoning or illness is the result of eating contaminated food. Micro-organism are the basic cause of contamination of food.
Food Contamination is the presence of any substance which is not intentional food, and is present in food as a result of the production, manufacture, processing, preparation, treatment, packing, packaging transport or holding of such food or as a result of environmental contamination. The term does not include insect fragments, rodents, hairs and other extraneous manner.
In some of the foods commonly consumed by man substances harmful to the human health occur and they are commonly referred to as contaminants of natural origin. In some they are present in minute quantities and may not present any health hazards. Some of these toxins get accumulated in the body or ingestion of small qualities for prolonged period may result in certain diseases.
It is a general term for small living creatures that cannot be seen through naked eye. They are visible only through microscopes. They are present in water, soil, air, in and on human and animal bodies etc. some of the micro-organisms are harmless to humans, some are useful and few are dangerous. They are broadly divided into four categories.
1. Yeast 2. Viruses
3. Moulds 4. Bacteria
1. Yeast: It does not cause food poisoning but some types may spoil the food. Yeast is single cell organisms, larger than bacteria that grow on foods containing moisture and sugar. Fruit juices and low sugar syrups contain small amount of sugar and good amount of moistures which is a favorable condition for yeast to grow and ferment if it gets suitable warmth. Yeast increases food spoilage therefore food should be stored in refrigerator. The ability of yeast to feed on sugar and produce alcohol is the basis of Beer and Wine making industry. We also use controlled amount of yeast to produce products. Bread and bakery. Yeast is destroyed by heat.
2. Moulds: The moulds are simple plants which appear like whiskers on the food surface of sweet food, cheese or meats. They are not the cause of food poisoning with the symptoms of sudden vomiting and diarrhea but some are capable of causing illness due to production of mycotoxins (poisonous substance). The moulds are killed by heat or sunlight. Correct storage in a cold dry store prevents moulds from forming. The growth will take place if the food article is stored in a damp condition with suitable temperature. Some moulds are useful too as they are harmless and commonly injected in the cheese to make blue cheese.
3. Viruses: They are smaller than Bacteria and cannot live of their own. They need living tissues to grow and multiply. Some of them may cause vomiting and diarrhea. A food handler may transfer it to the person eating the food but it does not grow in the food. The virus is destroyed by heating.
4. Bacteria: Majority of them cause food poisoning. These micro-organisms are further classified into:
– Harmful bacteria: They are cause of a disease PATHOGENS. With few exceptions, small numbers of pathogenic bacteria can be swallowed without causing any ill effect; but if large numbers are present in the food may cause food poisoning.
– Spoilage bacteria: Large numbers of such bacteria can cause food to deteriorate in various ways; for example;
> Milk turns sour due to growth of bacteria that produce acid as that grow and multiply.
> Meats and Fish start smelling on growth of such bacteria
These spoilage bacteria rarely cause food poisoning but if the storage is not proper and they multiply along with the harmful bacteria then the chances of food poisoning ml] persist. We should not eat anything which smells bad.
– Useful bacteria: Some bacteria which are used to produce cheese and curd or yoghurt are useful for the human body.
Transfer of Bacteria:
– By infected or dirty hands
-Through cuts, wounds and burns where they are present
-Coughing or sneezing on the food
-Unhygienic kitchen conditions; dirty working surfaces, equipments etc.
-Through contaminated food
– Through air and water
– By insects
– Because of poor waste disposal
Temperature range for bacteria:
– Bacteria stay inactive between temperatures of -20“C to 7C.
– Bacteria is active between 7‘C to 60’C 0Bacterial growth is stopped and it stays inactive if the temperature rises from 60’C
– To kill bacteria food needs to be pasteurized and then kept under proper storage.
Favorable conditions for bacteria to grow and multiply:
1. Warmth above 7’C and below 60C
2. Food-Gets it from the surface on which it is surviving
3. Moisture-gives them place to grow
4. Time-required for gestation
We should know what makes food contaminated by harmful bacteria and leads to food poisoning. Apart from personal and environmental hygiene following may become one of the reasons:-
– Food not stored in the fridge and kept at room temperature after cooking for a long time.
– Slow cooling of Food before putting it in the fridge. It should be cooled fast so that it does not get a chance of remaining at the temperature which is good for bacteria to grow and multiply.
– Food not heated up to a high temperature after taking it out from the fridge and gives a chance to bacteria to grow.
– Using contaminated food knowingly to cut down wastage. Remember it will be too costly saving for the company.
– Food not cooked to the desired state i.e. undercooking.
– Thawing is not done properly before actual preparation
– Contaminated food transferring contamination to raw food
– Contamination due to poor personal hygiene
– Using leftover food after a long gap.
– Poor storage
– The workers are not trained to follow proper storing procedures.
Store cooked food at a right temperature at a right place soon after it is cooked and cooled quickly. Raw material should be stored in the prescribed conditions and first in first out (FIFO) method should be applied.
Anything showing signs of spoilage should be removed and disposed off immediately