Sedimentation Test for Wheat and Flour

Method
1. A small sample of flour or ground wheat (3.2 grams) is weighed and placed in 100-milliliter glass-stoppered graduated cylinder.
2. Water (50 milliliter) is added to the cylinder and mixed for 5 minutes.
3. Lactic acid solution is added to the cylinder and mixed for 5 minutes.
4. The cylinder is removed from the mixer and kept in upright position for 5 minutes.
5. The sedimentation volume is recorded.


Results
• The sedimentation test is conducted by holding the ground wheat or flour sample in an acid solution.
• During the sedimentation test gluten proteins of ground wheat or flour swells and precipitate as a sediment.
• Sedimentation values can be in the range of 20 or less for low-protein wheat with weak gluten to as high as 70 or more for high-protein wheat with strong gluten.


Why is this important?
• The sedimentation test provides information on the protein quantity and the quality of ground wheat and flour samples. Positive correlations were observed between sedimentation volume and gluten strength or loaf volume attributes. The sedimentation test is used as a screening tool in wheat breeding as well as in milling applications.
Adapted from Method 56-61A, Approved Methods of the American Association of Cereal Chemists, 10th Edition. 2000. St. Paul, MN.