Preserving food becomes important when you want to eat it the next day or you are expecting a guest in a day or two.
The food has a slower rate of deterioration when kept in the refrigerator. The action of the bacterias is low in the refrigerator. Vegetables must be boiled first to destroy enzymes and microorganisms and then kept in the refrigerator.
There are foods whose enzymes can be destroyed easily by the microorganisms. That’s why it is important to keep the boiled preserves sealed in airless conditions to prolong their shelf life.
3- Strong acids
Alcohol, acid, and salt and sugar all create environments that prevent the growth of microorganisms. However, in the case of alcohol, destroy them completely. That’s why a fruit can be easily preserved in sugar solution or alcohol.
4- Air tight
The seal of fat or oil can be used to prevent any airborne microorganisms from coming into contact with food and spoiling it. The jars and bottles that preserve the prolonged shelf life by heat processing forces the air to escape as steam to leave a sterile vacuum.
5- No Moisture
There should be no moisture as microorganisms need moisture to grow, and die off in dry conditions. The food can be sealed in a concentrated solution of salt or sugar that draws out moisture by osmosis.