The Magic Dust - Part 2
In this sequel we will discuss the fermentation characteristics of flour, that is, the ability of flour to produce gas in the form of carbon dioxide.
Erre4m friends, good morning and welcome to this new post to continue talking about FLOUR. In the previous post we analyzed where flour comes from, which are its milling categories and finally we deepened that essential part related to the strength of the flour according to its gluten content and its W scale value. In this sequel we will talk about the fermentative characteristics of flour, that is the ability of flour to produce gas in the form of carbon dioxide. These fermentative characteristics depend on the flour's ability to form sugars, i.e. the extent to which the starch it contains can be broken down to glucose through the activity of enzymes present in the flour itself. The speed of sugar formation is directly proportional to the amount of enzymes and the degree of starch breakdown.
The technical laboratory in each mill uses a device called reofermentograph to analyse these characteristics. This device predicts the progress of fermentation and rising of a dough, its ability to develop and maintain its structure under the pressure of carbon dioxide, as well as the characteristics of the product obtained with the flour under examination, such as volume, structure of the crumb, fragrance and colour of the crust.
This test carried out with the reofermentograph has a high relevance, in fact knowing the fermentation capacity of the flour you can predict the activity of the fermentation of the dough and knowing the qualitative and quantitative characteristics of gluten, the volume and porosity of the finished product. The fermentation capacity of the flour, as mentioned above, also interacts on the color of the crust of the bread according to the quantity of sugars contained in it and remained in the dough after the action of yeasts until the moment of baking. During baking, a series of chemical processes are produced on the surface of the bread that give the crust its characteristic amber colour, taste and aroma.
The most important of these chemical processes is the CARAMELIZATION OF THE SUGARS of the surface layer on which aromatic and brown substances are formed, produced by the union of the sugars with amino acids derived from the complete hydrolysis of the proteins during baking (this process is called MAILLARD REACTION). In order to generate a good colouring of the crust, the quantity of sugars present in the dough at the time of baking is generally 2-3%.
We have seen that the sugars-carbohydrates present in the flour and partly responsible for its fermentation activities, are 80% made up of starch. This sugar, in addition to having a significant presence in the flour itself, has a number of important functions:
1. ABSORBS LIQUIDS DURING THE KNEAD
2. SACCHARIFIES DURING LEAVENING. The saccharification of starch is the chemical reaction that transforms starch, which is a polysaccharide, into simpler sugars thanks to the demolition action of the enzymes alpha and beta amylase. The saccharification proceeds splitting at first the starch in DESTRINS (4 molecules of glucose), subsequently split in half in MALTOSEUM (2 molecules of glucose), split in one molecule of GLUCOSE. The glucose obtained from the saccharification of starch is the nutrient for yeasts.
3. GELATINIZES DURING COOKING, i.e. in the oven when it reaches a temperature of 56-60°C the starch becomes a gel capable of absorbing water and forming the crumb.
4. IT INTERVENES IN THE CONSERVATION OF BREAD. After baking, as time passes, starch loses the water absorbed during the gelatinization process, producing moisture and intervening in the aging of the bread. This process is called RETROGRADATION: the amylose molecules come together to form a rigid structure; part of the water passes to the gluten and part migrates outwards, helping to harden the bread.
We conclude this journey on the knowledge of flour by analyzing in a little more detail the function of enzymes, which we have often talked about in previous posts. Enzymes are protein substances with a catalyzing function. By catalysts we mean those substances that have the ability to promote reactions even though they do not participate directly in the reactions that take place during the baking process, but they help to speed up the reactions themselves. In flour there are various types of enzymes, let's see them:
1. ALFA and BETA AMYLASE = they intervene in the process of saccharification of starch. ALFA-AMYLASES break down the internal bonds of the starch molecule to form dextrins. When alpha-amylases are too active, almost the entire starch molecule is broken down, generating many dextrins which, being water-soluble, increase the liquid part of the dough, leading to liquefaction and lowering its ability to absorb and retain liquids. For this reason the alpha-amylases are also called liquefying enzymes. BETA-AMYLASES attack the outer bonds of the starch molecule and dextrins, breaking them down little by little into maltose. Beta-amylases act more slowly than alpha-amylases and do not destroy the entire starch molecule. Therefore they are called saccharifying enzymes.
2. PROTEASES = they favour the process of disintegration of the proteins present in the flour called proteolysis. The function of proteases is to decrease the strength of the flour and the resistance of the dough, making it more extensible and malleable; the dough tends to increase in softness and volume because the glutinic mesh, losing rigidity, becomes longer, facilitating the development of the product (see post on autolysis)
And now...recipe! FILONCINI WITH RETURNING PASTA AND AUTOLYSIS (1000g dough)
184g carry-over dough
408g W260 flour
71g wholemeal flour
Knead the flours, carry-over dough and water at low speed for 5 min. the flours, the carry-over dough, the water and leave to rest for 20-30 min. in the machine to start the autolysis.
Remove the dough at higher speed for 5-6 min. adding in order: the salt, then the sugar and lastly the yeast.
Let it rest for 45 minutes, then divide it into 165g pieces, then roll it out with a rolling pin and roll it into a short loaf, leaving it to rest for another 15 minutes.
Stretch slightly, pinching the sides, place in cloths arranged in a fan shape covering the whole thing and leave to rise for about 60 mins at 24°C without letting it rise too much.
Arrange in baking tins (preferably perforated), make 2-3 cuts under the skin and bake at 240-250°C, opening the oven slightly to finish cooking for about 25 mins.