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By Chef Richard
Types of Bacteria
Bacteria are all
around us, in the air, water, ground, on our skin and in our bodies.
They are classified in a variety of ways, but for our purpose we can
categorize them in a more basic way.
Harmless
bacteria – Most bacteria fall into this category. They neither help us nor
are harmful to us. These bacteria have a specific purpose, but are not
a concerning to us in terms of food safety,
Beneficial
bacteria – Believe it or not some bacteria are helpful to us. Some bacteria are
used in foods to make cheeses and yogurts. And still others live in
our bodies to fight of harmful bacteria.
Undesirable
bacteria – Undesirable bacteria is responsible for food spoilage. This type of
bacteria may not make you sick, but they show themselves by the use of
odors, sticky or slimy surfaces and discoloration.
Illness causing
bacteria or pathogens –
These are the bacteria that cause most food-borne illnesses. Pathogens
do not necessarily leave detectable odors or taste in food. This makes
it impossible to tell if food is contaminated by smelling or tasting,
or looking at it. The only way to protect yourself from this bacteria
is by proper food handling and sanitation.
Bacteria Growth
Bacteria simply
multiply by splitting in half. Under the ideal conditions, they can
double in number every 15 to 30 minutes. This means that one single
bacterium could multiply to a million in less than 6 hours.
What do
bacteria need to multiply?
Food
– Some from of food is a basic requirement for bacteria to grow.
Moisture
– Water is required for bacteria in order to absorb food. Dry foods
will not support bacterial growth. As well, foods with very high salt
or sugar content make bacteria unable to use the moisture present.
Temperature
– Bacteria grow best at warm temperatures between 40 and 140°F. This
temperature range is what we call the food danger zone.
Air
– Most bacteria require oxygen to grow,
but not all. There are some exceptions, one type of bacteria being
botulism.
Time
– When bacteria are introduced to a new environment, they need time to
adjust before they start to grow. This time is called the lag phase
and last about one hour.
How is bacteria
transferred?
Bacteria are
carried from one place to another by being carried. This can happened
by peoples hands, coughs, other food, utensils, equipment, water, or
pests.
Preventing
Bacteria Growth
Now that we know
how bacteria grow and are spread; we should be able to prevent
food-borne illness by following three simple steps.
- Keep bacteria
from spreading by not letting anything that might contain bacteria
tough the food. This includes people, dirty equipment, utensils and
possibly other foods.
- Stop bacteria
from growing by taking away the conditions that encourage growth.
The most effective way is to keep food out of the danger zone. Keep
foods below 40°F and above 140°F
- Finally kill
the bacteria. Most bacteria are killed if they are subject to a
temperature above 165°F for 30 seconds. This is how we make food
safe by cooking. This heat is also how we sanitize dishes and
equipment. Certain chemicals (such as bleach) also kill bacteria.
Using sanitizing agents is best way to sanitize counter tops and
large equipment.
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