Food Poisoning -- and How to Prevent
It Changing lifestyles in the modem world have resulted in
an increased demand for ready-to-cat foods, fast foods and dining out. This
change in demand has, in mm, brought with it new and increased problems. One of
these is the risk of bacterial food poisoning. How does food
poisoning occur Usually, it takes large numbers of food poisoning bacteria to
be present in food in order to cause illness. However, given the right
conditions, bacteria can multiply very rapidly. These conditions
include: Time -- In ideal conditions, one bacterium can
multiply to 2,097,152 within seven hours. Temperature --
Food poisoning bacteria grow best in the temperature range of 5℃ --
60℃. This is called the temperature danger zone. Food should not
be left in the temperature danger zone. Nutrients --
Bacteria need their own food source to grow and multiply. The types of foods
which bacteria prefer include dairy products, egg products, meat and poultry,
small goods, not including salami (意大利腊肠), processed meat and chicken products,
fish, shellfish and fish products. Because bacteria multiply
rapidly in these foods, they are known as high risk foods. High risk foods which
have been contaminated (污染) with food poisoning bacteria and then left in the
temperature danger zone can cause food poisoning to anyone who consumes
them. Water -- Without moisture, the growth of bacteria
slows down and may stop. Drying is an effective form of food
preserving. How does food become contaminated Food is
contaminated through poor handling and storage and through lack of personal
hygiene (卫生学) by the people who prepare and serve it. Food poisoning bacteria
are very widespread. They can be found in the soil, on animals and on people.
Because of this, it is possible for foods such as raw meat, poultry and
vegetables to contain these bacteria from the start. A common way that food can
become contamination, is through cross contamination. This can occur in two
ways: During food preparation, hands, utensils (器具) and equipment
such as cutting boards can become contaminated with bacteria from raw food. If
these utensils, equipment and hands are then used to prepare ready-to-eat or
cooked food, without first being thoroughly washed, then this food can become
contaminated with bacteria from the raw food. As this food is not cooked again
before being consumed, the bacteria in it will not be killed by
cooking. During storage, bacteria from raw food can contaminate
ready- to- eat or cooked food if the later are not stored separately. If they
are stored in the same refrigerator, raw food should always be stored in the
lowest part of the refrigerator and ready-to-eat or cooked food on the shelves
above. This prevents liquids from the raw food dripping on to the cooked food.
Store food in clean non- toxic washable containers or cover with foil or plastic
film. How can food poisoning be prevented Food poisoning can be
prevented by: (1) Preventing food from becoming
contaminated. (2) Preventing the bacteria in the food growing
and multiplying. We can think of food poisoning as being a chain
of circumstances: ·There must be bacteria on the food.
·The bacteria have the right conditions to grow-warmth ( between 5℃ and
60℃) , moisture and food. ·The bacteria have time to grow and
multiply. If this chain of events can be broken, food poisoning
can be prevented. Some of the ways of breaking this chain
are: ·Making sure your hands are dean before handing
food. ·Thoroughly washing all equipment used for preparing raw
foods. ·Storing raw foods below cooked foods in the
refrigerator. ·Storing food correctly -- not in the Temperature
Danger Zone. ·Making sure food is served as soon as possible
after preparation. Some Common Food Poisoning
Bacteria Salmonella (沙门氏菌) Commonly found in: meat,
poultry, eggs and egg products. Symptoms: nausea (恶心), stomach cramps,
diarrhea (痢疾), fever and headache. Onset(发作): 6 -- 72 hours after
consuming contaminated food. Symptoms can last from 3--5
days. Bacillus (杆状菌) Commonly found in: Cereals, rice, meat
products, packet soups. Symptoms: nausea, vomiting, diarrhea and
stomach cramps. Onset: 1--6 hours after consuming the contaminated
food. Symptoms usually last no longer than 24 hours. Note: These
bacteria produce spores which are not killed during cooking. When cooked food
containing these spores, has been left in the temperature danger zone, the
spores produce toxins (poisons) in the food which can cause food
poisoning. Staphylococcus aureus Commonly found in: Meat and
poultry dishes, egg products mayonnaise-based salads, cream or custard filled
desserts. Symptoms: acute vomiting, nausea, occasionally diarrhea and
cramps. Onset: 30 minutes -- 8 hours after consuming the contaminated
food. Symptoms usually last about 24 hours. Note: These bacteria
produce toxins in food. The toxin is not destroyed during cooking so correct
storage of food before and after cooking is essential. These bacteria are
commonly found on the skin and in the nose and mouths of healthy
people. Therefore, it is important that you maintain high
standards of personal hygiene (卫生学) when working with food. People with open
cuts or wounds on their hands and arms must ensure that the injury is completely
protected by a waterproof bandage. Other common food poisoning bacteria
include: ·Clostridium perfringens. ·Vibrio
parahaemolyticus. ·Listeria monocytogenes. Nowadays, people’s lifestyles are changing, which has resulted in the demand for fast foods.