Technology of Baked Goods - Sourdough Biotechnology - page 57

toxicity, is cheap and easy to use, and it has a high solubility at room temperature.
On the basis of the rapidity of the reaction, the chemical agents are classified as: fast
or immediate, slow or delayed, and double acting powders. The former develop gas
as soon as they are introduced into the dough. The delayed acting powders determine
the formation of negligible quantities of gas during mixing, which only develops at
high temperatures during baking in the oven. The double effect powders react in part
at room temperature and in part during baking, and in this case two acids are involved,
one soluble and one insoluble. The reactivity of a chemical agent is expressed as the
“neutralization value” (g of NaOH that are neutralized by 100 g of acid salt).

3.4 Baked Goods Making Process

A very large number of baked goods are manufactured worldwide. Breads are the
most diverse and several differences are found, for instance, between those manu-
factured in the Mediterranean areas and those from the Anglo-Saxon market [ 40 ] .
Overall, in the Mediterranean areas no significant quantities of sugar or other high
hydrophilic substances are added and pans are generally not used in the leavening
and baking stages.
Apart from the large variety of baked goods, the technological process may be
summarized in a sequence of operations that require long periods of time and which
have the primary objective of aerating the dough and making it porous (Table 3.2 ).

3.4.1 Discontinuous Processes (Straight-Dough and Sponge-

and-Dough)

Bread making, both at artisan and industrial levels, is traditionally a discontinuous
process since the various stages of mixing, leavening and baking are carried out on
limited quantities of materials and in separated facilities. Discontinuous bread-making
processes are performed using the straight-dough or the sponge-and-dough meth-
ods. Bread making with sourdough could be considered as a particular sponge-and-
dough method. Bread characteristics are influenced not only by processing but also
by flour and formula. In the straight-dough method, the fastest and easiest to man-
age, all the ingredients are mixed together simultaneously to form a dough which is
then left to rise (Table 3.3 ). Fermentation has to be carried out at least in two stages.
The first leavening is generally made with large quantities of dough, and for variable
times (from 30 min to 3 h), depending on the process. The primary objective of this
operation is not to get a volume increase, but to induce changes in the rheological
properties of the dough [ 41 ]. The first leavening provides a greater workability to
the dough, which achieves the capacity to maintain shape during the second leavening
(or proofing). In this stage, individual pieces of dough, corresponding to the final size,