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. For bacteria
to survive and reproduce into a large numbers there must be favourable
condition.
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. For bacteria
to survive and reproduce into a large numbers there must be favourable
condition.
At a temperature above 600C
bacteria is killed thereby stopping food poisoning due to absence of bacteria.
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. 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.
bacteria is killed thereby stopping food poisoning due to absence of bacteria.
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. 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 poisoning due to
bacteria is influenced by the following factors:
bacteria is influenced by the following factors:
1. Temperature
2. Water
3. Food /nutrients
4. pH
5. Oxygen
1. Temperature: Whether bacteria will survive or not can cause food
poisoning is determine by the temperature. 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. When temperature
is low, the activities of bacteria are inhibited and the bacteria are dormant.
poisoning is determine by the temperature. 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. When temperature
is low, the activities of bacteria are inhibited and the bacteria are dormant.
2. Water: Water or moisture is required by bacteria to grow
and reproduce in other to 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. 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.
and reproduce in other to 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. 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.
3. Food/Nutrients: 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 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
need food and energy for their survival.
contain items such as sugars, starch, protein, fats and others compounds
provide the nutrients. The presence 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
need food and energy for their survival.
4. 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.
5. Oxygen: 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. 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.
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. 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.
