Q. What is gluten?
What is gluten? Certainly you know that gluten is the protein found in wheat. Gluten is more or less made up of equal parts of gliadin and glutenin. Look up section 4.3 in the theory course (MFN-008) under the dough formation function to recapitulate what you learnt about gluten and its functional properties, particulary with respect to dough formation. This will help you understand the behaviour of gluten more precisely.
The flour absorption is the amount of water that flour can take up and hold while being made into simple dough.
Cake flour has 7-9% protein, all purpose flour has protein content of 9-10%. Bread flour has a protein content of 12.5-13.5 per cent. The protein consists of ~80% gluten. Gluten of cake flour is weakest, whereas, that of bread flour is the strongest. Flour is graded as to its strength depending on its gluten content whether, weak, medium and strong. Let us see how flours are graded based on the gluten content. Weak flour (also known as soft flour or hi-ratio flour) has a low gluten content of approximately 8% and is therefore ideal for delicate cake and sponge production.
Medium flour (also known as all purpose flour) is produced so that it is suitable for products that have to be chemically aerated. It is weak enough to stop toughening but strong enough to stand the pressures of the gases resulting from the use of baking powders etc. It is also a good all round flour for bread-crumbing, batters, scones etc. Strong flour has a high gluten content that makes it ideal for yeast products, breads and puff pastry.