Fermentation

Fermentation is the natural process by which sugars are converted into alcohols and acids by microorganisms.

Applications in the food industry

It has many important applications in the food industry such as:

1. Preservation

The nutritional content of milk, for example, can be preserved by turning it into cheese, and in the pickling process, fruit and vegetables are protected from the ill effects of microbial spoilage by the acids that ‘good’ bacteria form during fermentation.

2. Creating new products

A good example is beer – it results from the action of microorganisms on a mixture of cereal grains and water. Equally, the realisation by our ancestors that yeast has raising properties revolutionised bread production.

3. Modifying properties

Our diets would be far less diverse if it were not for fermentation. A vast variety of cheeses, for example, is available because of the different fermentation properties of various microorganisms.

A starter culture is the small quantity of yeast, mould or bacteria that is added to start the fermentation process off and begin the production of a food. Examples include the yeast added to bread dough, and lactic bacteria cultures that initiate the formation of yoghurt from milk.

Other benefits of fermentation

• in agriculture they are used as alternatives to conventional pesticides.
• in pharmaceutical area they are used to produce among other things antimicrobials (penicillin), vitamins and vaccines.