At pastries in test preparation the fermentative microflora is suppressed, activity of enzymes changes, there is a kleysterization of starch and a thermal denaturation of proteins, humidity and temperature of inside layers of dough, grain products changes. At a temperature of 55 - 60 C die off yeast and netermoorilny lactic bacteria, and at a temperature of 80 C also termoorilny bacteria perish.
The baked products, as a rule, arrive on conveyors on circulating tables where sort them and stack in wooden trays (products with defects reject). Products stack flatwise in 1 row – rich. A square loaf in 1 – 2 row on a lateral and lower crust, podovy bread, rolls, long loafs - in 1 row on the lower crust or on an edge.
Sent is a reduction of mass of test preparation at pastries, that is a difference between the mass () of dough and mass of a hot product (M. Upek (Municipal unitary enterprise) is expressed as a percentage to the mass of dough before landing it in the furnace.
Shrinkage is a reduction of mass of the baked products in the course of storage. For definition of shrinkage for a certain period it is necessary from the mass of hot bread (M to subtract the mass of bread after storage (). Usually shrinkage is expressed as a percentage in relation to the mass of hot bread.
Pastries – the final stage of production of grain products which is finally forming quality of bread. All products and processes turning dough into ready bread result from warming up of test preparation and moistening of its surface during pastries.
Such conditions provide intensive fermentation in test preparations and a good shape of their surface. The end of a rasstoyka of test preparations is determined organoleptic by increase in volume of dough, and also by easy pressing by fingers on a dough surface.
In the course of a final rasstoyka test preparations are intensively loosened and considerably increase in volume, the surface of preparations becomes smooth and elastic that provides a standard look and good porosity of a product. In the course of a rasstoyka along with fermentation also other processes of maturing of dough proceed.
Change of a state starch together with changes of albumens is the main process turning dough into a grain crumb. Humidity of a crumb of hot bread (in general) increases in comparison with humidity of test for 1,5 – 2,5% at the expense of the moisture which passed from the top layer of preparation. Change of a condition of albumens begins at a temperature of 50 - 70 C and comes to an end at a temperature about 90 C.
Give steam which condensation on a surface of preparations detains dehydration of the top layer and formation of a crust to the first zone of a baking chamber. However in a few minutes the top layer, getting warm up to the temperature of 100 C, starts losing quickly moisture and at a temperature of 110 - 112 C turns into a thin crust which then is gradually thickened.
Shrinkage for the maximum period of storage of a product at the enterprise makes 3 – 4% of mass of hot production. Shrinkage is caused by that at storage of grain products moisture from a crumb moves to a crust and from its surface evaporates in environment. As humidity of a crumb is always higher than humidity of a crust, the hot product dries out especially intensively, and cooled down dries out slowly. The quicker products will be cooled, the lower there will be a shrinkage for the same period of storage.
Influences the size of shrinkage as well other factors: humidity of a product, a condition of its crust, a specific surface of bread, temperature and humidity of air in hlebokhranilishche. For decrease in shrinkage it is necessary to cool quickly products, and then to store them in the conditions which are slowing down an usykhaniye. At some enterprises of a trolley with the baked products close plastic covers. All these measures not only reduce shrinkage, but also slow down production cherstveniye. Considerably shrinkage of unitary enterprise decreases.