Pro Tip: Determining the structure-function relationship of wheat starch allows millers and bakers to fine-tune processes, maximize bread quality and extend product freshness.
Wheat starch is a fundamental component in breadmaking, interacting with water, proteins, enzymes and other ingredients to shape dough properties and the final bread quality. Starch, composed of amylose and amylopectin, exists in granules that differ in size and thermal behavior. This affects how the dough absorbs water and how starch integrates into the gluten network, which ultimately influences the bread’s texture, volume and shelf life.
The milling process has a significant impact on wheat starch quality. During milling, starch granules can be damaged, affecting their ability to hydrate and swell during dough formation. While some degree of starch damage is necessary to promote hydration and gas retention, excessive damage can lead to a weakened dough structure, resulting in lower loaf volume and poor crumb texture. Optimal starch quality supports better dough rheology and improves the final product's characteristics.
The interactions between starch and proteins are crucial during mixing. Gluten development relies on water availability, and starch competes with proteins for hydration. Smaller B-type granules, which integrate more evenly into the gluten network, contribute to a more cohesive dough, while damaged granules or irregular shapes can cause inconsistencies.
Amylase enzymes are essential in breaking down starch into fermentable sugars, such as maltose, during fermentation and baking. These sugars feed the yeast, helping the dough rise and improving texture. However, the balance of enzyme activity is crucial — insufficient amylase can lead to reduced loaf volume and denser bread.
During baking, starch undergoes gelatinization, where the heat disrupts crystalline structures, allowing amylose to leach out. This process plays a key role in setting the crumb structure. Starch also forms complexes with lipids, which help stabilize the crumb and delay retrogradation, a major factor in bread staling.
Post-baking, the staling process is largely driven by the retrogradation of amylopectin, which leads to increased crumb firmness over time. Proper control of starch-lipid interactions and the use of enzymes can slow this process, extending the bread's freshness. Additionally, factors such as baking temperature, water content and storage conditions can influence the rate of staling and moisture migration between the crust and crumb.
Understanding the structure-function relationship of wheat starch allows millers and bakers to fine-tune processes, maximize bread quality and extend product freshness. By focusing on the delicate balance between starch properties and their interactions with other dough components, industry professionals can enhance not only the production process but also the consumer experience.
Reference:
Van Rooyen, J., Simsek, S., Oyeyinka, S. A., & Manley, M. (2023). Wheat starch structure–function relationship in breadmaking: A review. Comprehensive Reviews in Food Science and Food Safety, 22, 2292–2309. https://doi.org/10.1111/1541-4337.13147
Dr. Senay Simsek, serving as the department head, professor and dean’s chair in food science at Purdue University, possesses a background in cereal science, technology and wheat quality. Her goal is to foster collaboration between producers, scientists and food processors, optimizing research potential in this area.
