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Flour and Dough Test>Alveograph

Flour and Dough Test>Alveograph

Alveograph

**Method**

1. A sample of 250 grams of flour is mixed with a salt solution to form a dough.

2. Five 4.5 centimeter circular dough patties are formed and then rested in the alveograph in a temperature-regulated compartment at 25 degrees Celsius for approximately 20 minutes.

3. Each dough patty is tested individually. The alveograph blows air into a dough patty, which expands into a bubble that eventually breaks.

4. The pressure inside the bubble is recorded as a curve on graph paper.

**Results**

• The alveograph determines the gluten strength of a dough by measuring the force required to blow and break a bubble of dough.

• The results include P Value, L Value, and W Value.

• A stronger dough requires more force to blow and break the bubble (higher P value).

• A bigger bubble means the dough can stretch to a very thin membrane before breaking.

• A bigger bubble indicates the dough has higher extensibility; that is, its ability to stretch before breaking (L value).

• A bigger bubble requires more force and will have a greater area under the curve (W value).

• Alveograph curves are described on page 50.

**Why is this important?**

The alveograph test provides results that are common specifications used by flour millers and processors to ensure a more consistent process and product. The alveograph is well suited for measuring the dough characteristics of weak gluten wheats. Weak gluten flour with low P value (strength of gluten) and long L value (extensibility) is preferred for cakes and other confectionery products. Strong gluten flour will have high P values and is preferred for breads.

The alveograph test measures and records the force required to blow and break a bubble of dough.

• P Value is the force required to blow the bubble of dough. It is indicated by the maximum height of the curve and is expressed in millimeters (mm).

• L Value is the extensibility of the dough before the bubble breaks. It is indicated by the length of the curve and is expressed in millimeters (mm).

• P/L Ratio is the balance between dough strength and

extensibility.

• W Value is the area under the curve. It is a combination of dough strength (P value) and extensibility (L value) and is expressed in joules.

Weak gluten flour has lower P values than strong gluten flour.

*Adapted from Method 54-30A, Approved Methods of the American Association of Cereal Chemists, 10th Edition. 2000. St. Paul, MN.*