What Kind of Protein Is in Flour?

November 12, 2025 •

4 min read

Over 80% of the protein content in wheat flour is made up of gliadin and glutenin, which are the primary components of gluten. This unique protein composite is what gives dough its distinctive elasticity and structure, but the type and quantity of protein can vary significantly depending on the flour. Understanding these proteins is key to mastering different baking techniques, from chewy bread to tender cakes.

Quick Summary

Flour contains two main proteins, gliadin and glutenin, which form gluten when mixed with water. This protein network is responsible for dough's elasticity and extensibility, directly impacting the texture of baked goods. The total protein content and the balance between gliadin and glutenin vary by flour type, influencing its best uses, and other non-gluten proteins also contribute to the flour's overall properties.

Key Points

Gluten Proteins: Flour contains gliadin and glutenin, which are the two main proteins that form the gluten network when hydrated.
Gliadin's Role: Gliadin is the protein responsible for the dough's extensibility, allowing it to stretch.
Glutenin's Role: Glutenin provides the dough with elasticity and strength, enabling it to hold its shape and rise.
Protein Content Variation: The percentage of protein varies widely across different flour types, from low-protein cake flour to high-protein bread flour.
Impact on Baking: Higher protein flour yields a chewier, denser product, while lower protein flour creates a softer, more tender texture.
Non-Gluten Proteins: Flour also contains non-gluten proteins like albumins, globulins, and enzymes, which contribute to its nutritional profile and affect fermentation.
Kneading's Purpose: The mechanical action of kneading strengthens and aligns the gluten network, which is essential for trapping gas and achieving a good rise in yeast breads.
Protein and Water Absorption: Higher protein flours absorb more water, a crucial factor for proper dough hydration in bread-making.

The Dynamic Duo: Gliadin and Glutenin

At the heart of flour's functional properties are two specific proteins: gliadin and glutenin. These two types of proteins are stored within the wheat kernel's endosperm and remain separate until they are hydrated. The magic happens when you add water to flour and begin to mix or knead the dough. The gliadin and glutenin molecules link together, forming a continuous, three-dimensional network known as gluten.

The Roles of Gliadin and Glutenin

While they work together to form gluten, gliadin and glutenin each play a distinct role in shaping the dough's characteristics.

Gliadin: This is the alcohol-soluble component of the gluten complex, known for being sticky and extensible. Gliadin is responsible for the flow properties of the dough, allowing it to stretch without tearing. A higher gliadin-to-glutenin ratio can lead to a more extensible but potentially weaker dough.
Glutenin: This component is the alcohol-insoluble fraction and is a large, complex polymer. Glutenin provides the gluten network with strength, elasticity, and resistance to deformation, allowing the dough to spring back into shape. It gives the dough its structure and is what helps a loaf of bread rise.

The balance between these two proteins is critical. A proper gliadin-to-glutenin ratio is essential for creating dough with the right balance of viscosity and elasticity for its intended use.

The Impact of Protein Content on Different Flours

The percentage of protein in flour directly correlates with its gluten-forming potential, and this varies significantly across different types of flour. Flours are often categorized based on their protein content, which determines whether they are considered "hard" (high protein) or "soft" (low protein).

Flour Protein Content and Baking Applications


Flour Type	Protein Content (Approx.)	Gluten Potential	Typical Uses
Cake Flour	7–9%	Very Low	Soft, delicate baked goods like cakes, biscuits, and muffins.
Pastry Flour	8–9%	Low	Tender, flaky pastries and pie crusts.
All-Purpose Flour	9–12%	Medium	Versatile for a wide range of baked goods, from cookies to bread.
Bread Flour	12–16%	High	Chewy, structured baked goods like artisan bread, pizza dough, and bagels.
Whole Wheat Flour	Up to 16%	High	Nutritious, dense baked goods. The bran and germ interfere with gluten development.

Other Proteins in Flour

While gluten is the most prominent protein, flour also contains other types of proteins, known as non-gluten proteins. These include:

Albumins and Globulins: These are water-soluble proteins that play roles as enzymes and structural components within the grain. They make up a smaller portion of the total protein and contribute to the flour's nutritional value and baking functionality, such as fermentation rate.
Enzymes: These are specialized proteins that break down complex molecules. For example, amylase enzymes break down starch into sugars, which provides food for yeast during fermentation and affects the dough's gassing power.

Gluten Development and Its Role in Baking

The process of gluten development is what makes wheat flour so unique in baking. When you knead dough, you are manually aligning and strengthening the gliadin and glutenin proteins into a cohesive, elastic network. This network is crucial for trapping the carbon dioxide gas produced by yeast or other leavening agents. The trapped gas allows the dough to rise and expand, creating the signature light and airy texture of bread.

The amount of gluten development depends on several factors:

Mixing and Kneading: The more a dough is mixed, the stronger the gluten network becomes. This is why bread dough is kneaded vigorously, while cake batter is mixed minimally to keep it tender.
Hydration: Water is necessary for the gliadin and glutenin proteins to hydrate and form gluten. Flours with a higher protein content require more water.
Fats and Sugars: Ingredients like fats and sugars can interfere with gluten development by coating the protein molecules, resulting in a more tender crumb.

For those with gluten sensitivity or celiac disease, gluten-free flours, which do not contain gliadin or glutenin, are necessary. These flours, made from grains like rice, quinoa, and maize, use alternative binders to achieve a desired texture.

Conclusion: The Importance of Knowing Your Flour's Protein

Understanding the role of the proteins in flour is essential for any baker seeking to control the final texture of their products. The interplay between gliadin and glutenin creates the gluten network, and its strength, elasticity, and extensibility are dependent on the flour's protein content. From the high-protein hard wheats used for chewy, artisanal breads to the low-protein soft wheats for delicate cakes, the protein composition is the key determinant of a flour's functionality. By selecting the right flour and handling it appropriately, you can unlock the full potential of these fascinating proteins.

Higher protein develops more gluten for a chewy, elastic dough.
Lower protein develops less gluten, resulting in a soft, tender baked good.
Gliadin contributes to dough's extensibility (stretchiness).
Glutenin provides dough with its strength and elasticity (snap-back).
Baking applications are best matched with flours of corresponding protein levels for optimal texture and rise.

Frequently Asked Questions

When you mix wheat flour with water, the proteins gliadin and glutenin link together to form an elastic network called gluten. This network gives dough its unique structure and elasticity, which is essential for baking.

Hard flour is milled from hard wheat and has a higher protein content (over 12%), resulting in a stronger gluten network that is ideal for chewy bread. Soft flour, from soft wheat, has a lower protein content (7-9%), producing a more delicate, tender crumb perfect for cakes and pastries.

Gluten is crucial for bread because its stretchy, elastic network traps carbon dioxide gas produced by yeast during fermentation. This trapped gas allows the dough to rise and expand, creating the light, airy texture of a finished loaf.

No, gluten does not exist in flour until it is mixed with water. The flour contains two separate proteins, gliadin and glutenin, which combine to form the gluten network only after hydration and mixing.

A flour with high protein content will develop a strong gluten network, leading to a chewy, dense texture, like in artisan bread. Low protein flour develops less gluten, resulting in a softer, more delicate texture, such as in cakes.

Yes, flour also contains non-gluten proteins, including water-soluble albumins and globulins. These proteins act as enzymes and contribute to the flour's overall nutritional value and fermentation process.

Kneading is a mechanical process that strengthens the gluten network. It aligns and elongates the protein strands, increasing the dough's elasticity and helping it trap gas more effectively.

The amount of water a flour can absorb is influenced by its protein content. Higher protein flours require more water to fully hydrate the proteins and develop the gluten network, while lower protein flours need less water.