For bacteria to cause food
poisoning there must be favourable conditions for the bacteria to thrive, grow
and reproduce. Bacteria are always present in food items, but for them to cause
food poisoning they must be present in large number.
poisoning there must be favourable conditions for the bacteria to thrive, grow
and reproduce. Bacteria are always present in food items, but for them to cause
food poisoning they must be present in large number.
Temperature is an
important determinant to the survival of bacteria. At a very high temperature,
say above 600C bacteria are killed thereby and this stop food
poisoning. When the temperature become too cold such as that of the
refrigerator, bacteria becomes dormant this means that keeping food at low
temperature does not kill the bacteria but only stops them from multiplying.
Once the conditions are favorable again, they will wake up and start growing
again.
For micro-organisms to
cause food poisoning there must be bacteria at a large number to cause food
poisoning. For bacteria to survive and reproduce into a large numbers there
must be favourable condition. The activities of bacteria are important
determinants in the occurrence of food poisoning. 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. 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.
cause food poisoning there must be bacteria at a large number to cause food
poisoning. For bacteria to survive and reproduce into a large numbers there
must be favourable condition. The activities of bacteria are important
determinants in the occurrence of food poisoning. 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. 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.
Micro-organism require the
following conditions for bacteria to cause food poisoning:
following conditions for bacteria to cause food poisoning:
1. Temperature
2. Water
3. Food /nutrients
4. pH
5. Oxygen
1. Temperature: Temperature is an determinant for 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. Temperature must be at an optimum
temperature for bacteria to cause food poisoning. At a temperature around
normal body temperature (between 35oC to 40oC).
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. Temperature must be at an optimum
temperature for bacteria to cause food poisoning. At a temperature around
normal body temperature (between 35oC to 40oC).
2. Water: 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. With the absence of water or moisture, bacteria cannot
reproduce therefore cannot cause food poisoning. The absence of water or
moisture reduces the rate of reproduction of bacteria thereby reduce the rate
of food poisoning and the presence of water or moisture help bacteria to thrive
and reproduce and thereby leading to food poisoning. The presence or water or
moisture is a necessity for the growth and reproduction of bacteria. These
bacteria if present in large quantity will cause food spoilage.
for the many chemical reactions necessary for life and growth, and allows waste
products to escape. With the absence of water or moisture, bacteria cannot
reproduce therefore cannot cause food poisoning. The absence of water or
moisture reduces the rate of reproduction of bacteria thereby reduce the rate
of food poisoning and the presence of water or moisture help bacteria to thrive
and reproduce and thereby leading to food poisoning. The presence or water or
moisture is a necessity for the growth and reproduction of bacteria. These
bacteria if present in large quantity will cause food spoilage.
3. Food/Nutrients: For bacteria to survive there must be adequate
nutrition that is needed for bacteria to survive. These nutrients include
starch, sugar and carbohydrates. The absence of nutrients inhibits the growth
of bacteria and also reduces the reproduction of bacteria and the ability to
cause food poisoning.
nutrition that is needed for bacteria to survive. These nutrients include
starch, sugar and carbohydrates. The absence of nutrients inhibits the growth
of bacteria and also reduces the reproduction of bacteria and the ability to
cause food poisoning.
4. PH: 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 of a substance is measured with a pH which
has a scale of 0 to 14 with 7 being
neutral. The pH of food is a measure of the acidity or alkalinity of
the food substance. The pH is a term used to determine the acidity
or alkalinity of a substance. 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.
poisoning in food can also be determined by the acidity or alkalinity of the
food. The pH of a substance is measured with a pH which
has a scale of 0 to 14 with 7 being
neutral. The pH of food is a measure of the acidity or alkalinity of
the food substance. The pH is a term used to determine the acidity
or alkalinity of a substance. 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.
5. Oxygen: 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. There are different
characteristics of bacteria and if they exist at a very large quantity in food,
food poisoning occurs. Depending on the nature of the bacteria, the presence or
absence of oxygen determine their ability to cause food poisoning.
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. There are different
characteristics of bacteria and if they exist at a very large quantity in food,
food poisoning occurs. Depending on the nature of the bacteria, the presence or
absence of oxygen determine their ability to cause food poisoning.