Did you know that gluten is the real workhorse of the world’s delicious pastries and pasta? Think of gluten as the bond that holds together your favorite cookie, without it cookies would crumble at the touch. As a culinary scientist I like to know a little more about my ingredients and the science behind my creations, so below is some research I gathered on the subject. You can also check out my post on gluten-free flour alternatives and read what it’s like to bake without wheat flour.
What is Gluten?
Gluten is the common name for proteins present in all forms of wheat and related grain species like barley, rye, and triticale. Gluten is a critical functional protein component in wheat-based doughs. Gluten forms when two classes of water-insoluble proteins in wheat flour (glutenin and gliadin) are hydrated with water and mixed. From this process, gluten bonds form and a firm, rubbery substance is created providing strength and structure.
The mechanical shear causes the gluten bonds to form and become a viscoelastic matrix holding the starch granules in the flour. Only a batter or dough can contain gluten, not the raw flour alone. The bonds that form between the glutenin and gliadin are called disulfide bonds, as illustrated in the picture below.
(Image Source: Gluten Formation, www.perten.com)
If you’re a food geek like me, then you may enjoy this fantastic article on bread chemistry on the science behind bread making. Gluten is critical for bakers and cooks because it provides the proper texture and function resulting in our favorite dishes like pasta, bread, and pastries.
What is Gluten’s function in baking and cooking?
Gluten formation is critical to the volume, texture, and appearance of a product. When the proteins in the flour are hydrated, and the dough/batter is mixed, gluten bonds form providing structure and elasticity. This process happens because the proteins in the dough form linkages and gluten strands are created.
As mixing increases so does the strength of the dough. The amount of gluten formation is dependent on the application. Less gluten formation is desired in a tender cake, whereas high amounts of gluten formation is needed for chewy artisan bread. You can purchase various types of flour with more or less protein, depending on the desired level of gluten-forming potential.
Below provides the protein content of flour’s based on the type and use. You can see how the amount of gluten present in a recipe can affect the texture of the baked goods.
(Source: On Baking: A Textbook of Culinary Fundamentals)
When gluten bonds are formed, the protein then can form elastic films in the dough, which provides structure and helps to trap gases, assisting in leavening of products. When heated, the gluten proteins coagulate (solidifies), and a semi-rigid structure forms providing textures of various wheat-based products.
Starches are also an essential component in wheat flour (63-77%). As the product is heated, the starches absorb moisture and gelatinize (stiffens), adding to the texture of the finished product. The unique composition of nutrients in wheat flour (fat, minerals, moisture, starches, and proteins) provide the characteristic taste and texture attributes to wheat based products.
Many people cannot consume gluten-containing products because they have digestive challenges or celiac disease. There are now many gluten-free flour alternatives appearing in the baking aisle of your local grocery store. You can also read more about my personal experiences baking with gluten-free flour on my strawberry shortcake recipe and banana oat crunch muffins recipe pages.