Which one of the following is not a method of food preservation?

Boiling food in water cannot completely destroy all microorganisms. Only the cells of bacteria, yeasts and moulds can be destroyed at temperatures of 100°C or above. Moreover, it doesn’t preserve the food. The most commonly used food preservation methods are salting, drying, freezing and pickling.

* Salting is the preservation of food with dry edible salt.

* Drying or dehydrating food is a method of food preservation that removes enough moisture from the food so that bacteria, yeast and moulds cannot grow.

* Freezing, in food processing, is a method of preserving food by lowering the temperature to inhibit microorganism growth.

* Pickling is the process of preparing food by soaking and storing it in a salt solution, vinegar or both.