Abstract:
In the dough, carbon sources are constituted of flour glucides
represented by small quantities of glucose, fructose and sucrose. Glucose and
fructose can be directly metabolised as they are diffused through the cellular
membrane. There is a greater preference for glucose, which is the first to be
used in the dough. By decreasing the glucose concentration, the yeast uses
the fructose in the dough. The sucrose pre-existent in flour or which is added
in dough composition is hydrolysed to glucose and fructose by yeast
invertase. The monoglucides formed diffuse in the cytoplasm afterwards,
where they are metabolised. Yeast invertase is very active. It hydrolyses the
sucrose in the first minutes of mixing; therefore, at the end of this process,
the dough only has glucose, fructose and maltose. The introduction of
sucrose in the dough is a very common practice in bakeries. By introducing
this type of diglucid in the dough, we deal with an increase of fermentable
glucid quantity. As a consequence, yeast activity is accelerated. The process
occurs until a maximum degree of sucrose is added; afterwards, yeast
activity is inhibited. This is why we thought is would be interesting to
analyze, in this paper, the way in which an addition of 1.7-3% sucrose added
influences the fermentative activity of compressed yeast and bread quality. In
order to evaluate the fermentative activity of yeast, we used the device SJA
fermetograph and for the evaluation of bread quality, baking tests were
carried out. The products have been appreciated from the point of view of the
specific volume obtained. Both from the point of view of the fermentative
activity and from the point of view of baking samples, the best results were
obtained for 2-3% sucrose introduced in the dough obtained from a lowmedium quality type of flour used for breadmaking. For the evaluation of the
fermentative activity, the SJA device was used.
