Fermentation is an age-old process for transforming food so as to preserve it for longer. The process involves the action of micro-organisms — bacteria, yeasts, or moulds — which transforms sugars into acid. This acidification of the food can prevent the development of pathogenic bacteria, and the chemical reaction also modifies the taste and texture of the food by producing other compounds. Depending on the raw material and the type of fermentation, these new products can include alcohol, vitamins, carbon dioxide, fatty acids, new flavours, etc., all of which contribute to the sensory properties of fermented foods.
Fermented products are very much part of our daily diet. They include bread, wine, cheese, and sauerkraut, but also some kinds of sausages, olives, and even tea, coffee, and cocoa. Worldwide, it is estimated that around 5,000 different fermented products are consumed. In particular, many types of fermented vegetables are eaten in Asia. In the history of mankind, fermentation was the earliest method of preserving food.
There is an increasing number of studies devoted to fermentation, for a number of reasons. This biological process requires very little energy and
