What determines the gluten content in flour?

What determines the gluten content in flour?

The gluten strength of flour is primarily determined by the following factors:

‌Protein Content and Type‌

‌Core Components‌: Gluten proteins (gliadin and glutenin) in wheat flour form a network structure when hydrated, determining dough elasticity and extensibility.

‌Content Standards‌:

High-gluten flour: Protein ≥12.5% (e.g., bread flour)

Medium-gluten flour: 9%~12% (e.g., all-purpose flour)

Low-gluten flour: ≤8.5% (e.g., cake flour)

‌Wheat Varieties and Processing Techniques‌

‌Varietal Differences‌: Hard wheat (e.g., northern wheat) has higher protein content (12~14%), while soft wheat only 8~10%.

‌Processing Impact‌:

Excessive milling temperatures can damage gluten protein structure.

First-milled flour (extracted from the endosperm center) has better gluten strength than later-milled flour containing bran.

‌Storage and Usage Conditions‌

‌Improper Storage‌: High temperature and humidity can denature proteins, reducing gluten strength.

‌Operational Factors‌:

Insufficient kneading (requires >15 minutes) or over-fermentation weakens the gluten network.

Ice water should be used in hot summers to protect gluten.

‌Other Additive Influences‌

‌Illegal Additives‌: Talcum powder, borax, etc., can destroy gluten structure.

‌Natural Components‌: Whole wheat flour has lower gluten strength and shorter shelf life due to bran and germ content.

‌Conclusion‌: Gluten strength results from the combined effects of protein content, wheat varieties, processing techniques, and storage conditions. Choosing flour requires matching gluten strength to usage (e.g., high-gluten for bread, low-gluten for cakes).

The ST150 dough extensometer is a reliable testing instrument for determining the gluten strength of flour and the improvement effects of flour improvers (strengthening agents). It analyzes the extension resistance and elongation length of dough, processes the collected data with a computer, generates an extension curve, and calculates indicators such as dough extensibility, extension resistance, curve area, and tensile ratio to evaluate flour quality and the effectiveness of flour improvers.