Test Method for Rheological Properties of Wheat Flour Dough

Test Method for Rheological Properties of Wheat Flour Dough

Wheat flour dough is a semi-solid mixture with elasticity, extensibility, and plasticity. It is formed by mixing wheat flour and water in a certain proportion and kneading so that proteins absorb water to form a gluten network. It serves as the basic raw material for making pasta products such as bread, steamed buns, noodles, etc.

Experimental Purpose

1.Evaluate flour processing quality and classificationThe primary purpose of the experiment is to determine which pasta products the wheat flour is suitable for through rheological curves. Based on the stability time and softening degree measured by the farinograph, it is possible to clearly distinguish strong gluten flour (suitable for bread), medium gluten flour (suitable for steamed buns and noodles), and weak gluten flour (suitable for biscuits and cakes).The longer the stability time, the stronger the mixing resistance of the dough, making it more suitable for bread requiring longtime fermentation. This method can be used for special flour screening, as different pasta products have distinctly different requirements for dough properties.

2.Predict the final quality of pasta productsThere is a significant correlation between the rheological properties of dough and the quality of baked or steamed products, and the experimental data have strong predictability.

3.Guide the optimization of production process parametersThe experimental results can provide specific operational basis for actual production and avoid blind adjustment based on experience.

4.Monitor raw material stability and breeding selection

Batch stability monitoring: For flour processing plants, regular testing of rheological properties can monitor quality fluctuations of different batches of wheat flour to ensure product standardization.

Reference for wheat breeding: In agricultural research, rheological indicators are important criteria for screening highquality wheat varieties. By analyzing the alveograph properties (such as tenacity P, extensibility L, and strength W) of dough from different varieties, breeding experts can directionally cultivate new wheat varieties suitable for specific processing requirements.

Experimental Apparatus

Sample:Wheat flour dough

Apparatus: ST139 Electric Farinograph，conforming to ISO 55302

Experimental Procedures

• Sample weighing and water addition calculation

Based on 14% moisture basis, weigh 300 g of pretreated wheat flour sample, accurate to 0.1 g.Estimate the water absorption of the wheat flour and calculate the required water volume.

Water absorption (%) = (Water addition + Wheat flour weight − 300) / 3(Taking the 300g flour mixing bowl as an example, water addition is in mL.)

The final maximum consistency of the dough shall be 500 ± 20 BU.If the curve in the preliminary test exceeds 500 BU, the water addition is insufficient; otherwise, it is excessive. The water addition can be adjusted according to the relationship: 20 BU ≈ 0.6%–0.8% water absorption.

• Kneading and curve recording

Pour the weighed wheat flour into the 300g mixing bowl of the farinograph. Start the mixing bowl at a speed of 63 ± 2 r/min.Complete water addition within 25 seconds to ensure rapid mixing of water and flour.Timing starts from the beginning of water addition. The instrument automatically records the change in resistance of the dough to the mixing arms during kneading and generates a farinogram curve.

The conventional test lasts for 20 minutes. The test time can be appropriately extended for special analysis, but the integrity of data collection must be ensured.During the test, closely observe curve changes. If abnormal fluctuations occur, check the instrument status or sample condition.

• Parallel test setup

Each batch of samples shall be tested in at least 2 parallel tests.The allowable error of parallel tests is no more than ±1.5%.If the relative deviation exceeds 5%, the test shall be repeated to ensure data reliability.

Experimental Results and Analysis

The five wheat flours show significant differences in rheological properties and can be classified into four categories: strong gluten, mediumstrong gluten, medium gluten, and weak gluten according to farinograph parameters.The experimental results meet the requirements of GB/T 146142019.They can provide a scientific basis for raw material acceptance, quality control, and product development in flour enterprises, as well as data support for raw material selection and process optimization in pasta production enterprises.