Yeast for
bread making
During the fermentation of the bread, the yeast produces carbon dioxide and changes the physical characteristics of the dough thanks to the action of enzymes.
Two separate phases can be distinguished during the normal fermentation of bread dough comprising water, flour, salt and yeast.
Firstly, the yeast ferments the sugars which are directly assimilated by it and which are naturally present in the flour (comprising approximately 1.5% of its weight). The second phase involves the fermentation of the sugar in the flour known as maltose. The maltose is a result of the action of certain enzymes, (amylases) on the starch present in the flour, damaged during the grinding of the wheat. When the dough contains added sugar, (saccharose or glucose) this is directly fermented before the maltose. Consequently, for a product such as brioche, it is chiefly the saccharose which is consumed by the yeast. The unconsumed part contributes to giving the product a sugary taste. The action of the flour’s amylases is enhanced by that of maltase, another yeast enzyme which in turn breaks down the maltose to produce the simplest sugar, glucose. The latter is transformed by the yeast into carbon dioxide (which gives the bread its volume and provides the flesh with its honeycombed appearance) and into alcohol (which evaporates off during baking). The yeast also produces aromatic compounds which contribute to the overall aroma and flavour of the bread.
Two separate phases can be distinguished during the normal fermentation of bread dough comprising water, flour, salt and yeast.
Firstly, the yeast ferments the sugars which are directly assimilated by it and which are naturally present in the flour (comprising approximately 1.5% of its weight). The second phase involves the fermentation of the sugar in the flour known as maltose. The maltose is a result of the action of certain enzymes, (amylases) on the starch present in the flour, damaged during the grinding of the wheat. When the dough contains added sugar, (saccharose or glucose) this is directly fermented before the maltose. Consequently, for a product such as brioche, it is chiefly the saccharose which is consumed by the yeast. The unconsumed part contributes to giving the product a sugary taste. The action of the flour’s amylases is enhanced by that of maltase, another yeast enzyme which in turn breaks down the maltose to produce the simplest sugar, glucose. The latter is transformed by the yeast into carbon dioxide (which gives the bread its volume and provides the flesh with its honeycombed appearance) and into alcohol (which evaporates off during baking). The yeast also produces aromatic compounds which contribute to the overall aroma and flavour of the bread.
When we talk about yeast, people often think of the bakery world. However, by carefully selecting strains and developing multiplication techniques, yeast can be used for many other applications and in a wide range of activities such as the food industry, flavourings, pharmaceuticals and animal health, etc.
