Toxins are the metabolites that are produced by bacteria during their growth. These toxins are harmful to mankind. They produce many diseases in human. Many of the pathogenic bacteria produce toxins that cause food poisoning to humans.

Cooking:

Toxins inactivation by cooking depends on the toxin composition. Some toxins are heat stable toxins that are not destroyed by cooking. They remain stable at high temperature.

E.g. Staph.aureus produce heat-stable toxins that are not destroyed by cooking.

Some bacteria produce heat- sensitive toxins that are destroyed by cooking. Even small fluctuations in temperature, toxins protein denatures and breaks. When toxins protein chain breaks, it’s function loss. It is unable to produce the disease.

E.g. Clostridium botulinum produce heat sensitive toxins that inactivate when temperature increase.

Freezing:

Freezing can’t destroy the toxins that are produced by the bacteria. Freezing stops the metabolism of bacteria. When the temperature reaches its optimal condition, bacteria starts growing and produces its toxin again.