Food poisoning occurs when
food becomes harmful to man when consumed. This is a situation that occurs when
there are a large number of bacteria present in food. For bacteria to survive
and reproduce into a large numbers there must be favourable condition. The best
temperature for the survival of bacteria ranges with that of the normal body
temperature of humans 37oC to less than 60 oC as a result of this, food kept at very low temperature or very
high temperature can be preserved from food poisoning while food at the
temperature range of the survive of bacteria can be a very fertile ground for
bacteria to thrive, reproduce and cause food poisoning.
food becomes harmful to man when consumed. This is a situation that occurs when
there are a large number of bacteria present in food. For bacteria to survive
and reproduce into a large numbers there must be favourable condition. The best
temperature for the survival of bacteria ranges with that of the normal body
temperature of humans 37oC to less than 60 oC as a result of this, food kept at very low temperature or very
high temperature can be preserved from food poisoning while food at the
temperature range of the survive of bacteria can be a very fertile ground for
bacteria to thrive, reproduce and cause food poisoning.
At very low temperature,
bacteria becomes dormant this means that keeping food at low temperature does
not kill them, but only stops them from multiplying. Once the conditions are
favorable again, they will wake up and start growing again. When the
temperature is raised above 600C it kills bacteria thereby hindering
their ability to cause food poisoning. There are some special conditions needed
by bacteria to cause food poisoning. These conditions are:
bacteria becomes dormant this means that keeping food at low temperature does
not kill them, but only stops them from multiplying. Once the conditions are
favorable again, they will wake up and start growing again. When the
temperature is raised above 600C it kills bacteria thereby hindering
their ability to cause food poisoning. There are some special conditions needed
by bacteria to cause food poisoning. These conditions are:
1. Water
2. Food /nutrients
3. pH
4. Oxygen
5. Temperature
1. Water: water or moisture is necessary for bacteria to
thrive, grow and reproduce. Bacteria need water to dissolve food they use for
energy and growth. Water allows the food to get into the cells, is used for the
many chemical reactions necessary for life and growth, and allows waste
products to escape. This principle is due to the understanding that drying the
food item removes moisture (water) from it thereby preventing it from poisoning
since bacteria cannot survive without moisture. It is a very common practice to
dry food items such as meat or fish to preserve them.
thrive, grow and reproduce. Bacteria need water to dissolve food they use for
energy and growth. Water allows the food to get into the cells, is used for the
many chemical reactions necessary for life and growth, and allows waste
products to escape. This principle is due to the understanding that drying the
food item removes moisture (water) from it thereby preventing it from poisoning
since bacteria cannot survive without moisture. It is a very common practice to
dry food items such as meat or fish to preserve them.
2. Food/Nutrients: Bacteria need food and energy for their survival. All
bacteria require energy derived from substances that contain items such as
sugars, starch, protein, fats and others compounds provide the nutrients. The
presence of these sources of energy encourages the growth of bacteria to a very
high level that can enable them to cause food poisoning, while the absence of
these conditions will stop the bacteria from reproducing.
bacteria require energy derived from substances that contain items such as
sugars, starch, protein, fats and others compounds provide the nutrients. The
presence of these sources of energy encourages the growth of bacteria to a very
high level that can enable them to cause food poisoning, while the absence of
these conditions will stop the bacteria from reproducing.
3. PH: Most bacteria grow well at neutral pH
which is 7, but a lot of them can tolerate a pH range from 4.5-10.0.
If the PH value is below 7, the food is classified as acidic. And
when it is above 7 it is classified as an alkaline. Whether bacteria will or will not cause food
poisoning in food can also be determined by the acidity or alkalinity of the
food. The pH is a term used to determine the acidity or alkalinity
of a substance. The pH of a substance is measured with a pH which
has a scale of 0 to 14 with 7 being
neutral.
which is 7, but a lot of them can tolerate a pH range from 4.5-10.0.
If the PH value is below 7, the food is classified as acidic. And
when it is above 7 it is classified as an alkaline. Whether bacteria will or will not cause food
poisoning in food can also be determined by the acidity or alkalinity of the
food. The pH is a term used to determine the acidity or alkalinity
of a substance. The pH of a substance is measured with a pH which
has a scale of 0 to 14 with 7 being
neutral.
4. Oxygen: Bacteria come in different forms and nature, and if
they exists at a very large quantity in food, food poisoning occur. Depending
on the nature of the bacteria, the presence or absence of oxygen determine
their ability to cause food poisoning. Some bacteria require oxygen to grow
(aerobes) while others can grow only in the absence of oxygen (anaerobes). For
those that require oxygen to grow, all other condition being equal, the
presence of oxygen will help them to reproduce and cause food poisoning while
the absence of oxygen will stop them from causing food poisoning.
they exists at a very large quantity in food, food poisoning occur. Depending
on the nature of the bacteria, the presence or absence of oxygen determine
their ability to cause food poisoning. Some bacteria require oxygen to grow
(aerobes) while others can grow only in the absence of oxygen (anaerobes). For
those that require oxygen to grow, all other condition being equal, the
presence of oxygen will help them to reproduce and cause food poisoning while
the absence of oxygen will stop them from causing food poisoning.
5. Temperature: When temperature is low, the activities of bacteria
are inhibited and the bacteria are dormant. At this condition they still exit
in the food product but cannot cause food poisoning because they will be in
very little number. When the temperature is very high the bacteria are killed,
thereby stopping the bacteria from reproducing to a large number that can cause
food poisoning. The temperature of the food is important in determining whether
bacteria will cause food poisoning or not. Bacteria can thrive at a temperature
around 360C – 600C but the optimum temperature for bacteria is at
around 370C at favourable
condition, the bacteria reproduce to a large number hereby causing food
poisoning but at an unfavourable condition (at very high temperature, the
bacteria just die off while at very low temperature, such under refrigeration,
the bacteria freeze) thereby not being
able to cause food poisoning. This is the bases behind the principle of heating
food that are meant to be stored to a very high temperature to preserve the
food or keeping the food in the
refrigerator at a very low temperature to freeze the bacteria.
are inhibited and the bacteria are dormant. At this condition they still exit
in the food product but cannot cause food poisoning because they will be in
very little number. When the temperature is very high the bacteria are killed,
thereby stopping the bacteria from reproducing to a large number that can cause
food poisoning. The temperature of the food is important in determining whether
bacteria will cause food poisoning or not. Bacteria can thrive at a temperature
around 360C – 600C but the optimum temperature for bacteria is at
around 370C at favourable
condition, the bacteria reproduce to a large number hereby causing food
poisoning but at an unfavourable condition (at very high temperature, the
bacteria just die off while at very low temperature, such under refrigeration,
the bacteria freeze) thereby not being
able to cause food poisoning. This is the bases behind the principle of heating
food that are meant to be stored to a very high temperature to preserve the
food or keeping the food in the
refrigerator at a very low temperature to freeze the bacteria.
