AACCI Approved doughLAB Method

New AACCI Method 54-70.01 measures the mixing properties of dough in the doughLAB using high energy mixing to better emulate the high work rates commonly used in the dough mixers that are integral to modern, rapid bake systems. By using a faster mixing speed, results are achieved more quickly and are more accurate, more relevant and easier to interpret. AACCI method 54-70.01 is the only approved high energy flour and dough mixing test.

The doughLAB was introduced in 2004 as a high-intensity dough mixer designed to emulate the high work rates of modern dough mixers. It measures the resistance of a dough to mixing, including dough properties such as water absorption, dough development time, stability and other dough mixing characteristics.

Process Relevance

There is a need for a new method that can better emulate the high work rates of modern dough mixers.

Traditional flour mixing-quality tests were introduced during the early 20th century to suit the weaker flours and gentler processing conditions commonly used then. The traditional Farinograph method developed at the time (63 rpm; 1 W hr kg-1 dough), requires over 10 minutes to develop the dough.

Today, high-energy commercial dough mixers such as Peerless, Tweedy and similar, are commonly used in bakeries employing rapid bake systems. They impart mechanical energy to the dough at 2 - 4 W hr kg-1 dough, two to four times the rate added by older style mixers, and the mix time of the dough is typically just 2 – 5 minutes.

Dough performance depends on both the rate and amount of mechanical energy applied. The traditional method has been reported to provide poor predictions of bread flour processing requirements (water addition, optimum mixing energy, tolerance to overmixing) in modern bake systems.

Correct Peak Detection

There is a need for a new method that has more relevance to the strong flours now commonly used for breadmaking.

Modern bread-making flours such as those used for commonly making pan breads are stronger, taking longer to develop and producing "flat" curves using the traditional test. The method is prone to error when testing modern bread-making flours, making it difficult to correctly detect the dough development peak.

Many modern flours exhibit two mixing peaks due to harsher milling conditions. The first peak is frequently mistaken as the true development peak, leading to incorrect water addition, incorrect estimates of mixing time and tolerance, under-mixed doughs and sub-optimal product quality.

High extraction flours, especially those extracted and blended back from the reduction mills, often show a false "hydration" peak prior to the true mixing (gluten development) peak. In some cases the true mixing peak may not be evident during the traditional test Selecting the wrong peak will result in the wrong amount of water and mixing energy being added to the flour during commercial dough production.

Efficiency

Modern businesses need a new method that produces faster results.

The traditional method requires at least 20 minutes per test and two or more tests are required to optimize water absorption, resulting in a sample throughput of around 2 samples per hour. Modern businesses need to be able to assess more than two samples per hour.

The new test: AACCI 54-70.01

doughLAB Method

Test conditions in the doughLAB are 120 rpm (corresponding to a work rate of 3 W hr kg-1) at 30°C for 10 min. (Table 1). The Flour (300g or 50g) is weighed, added to the doughLAB bowl and the test started. The doughLAB automatically adds sufficient water to the flour to give a peak of 6,500 mNm (300g bowl) or 1,300 mNm (50g bowl).

The main differences from the traditional method are mixing speed (120 vs 63 rpm), target torque (about 30% higher) and test time (10 vs 20 minutes). Since mechanical energy is the product of mixer speed (angular distance) and torque (force), the rate of energy addition is about three times higher in the doughLAB method.

 
Table 1: Test profile of doughLAB standard method, AACCI 54-70.01

doughLAB Results

The doughLAB software, doughLAB for Windows (DLW), measures results, including peak torque (mN m), dough development time (min), stability (min), softening at 5 min after peak (mN m) and accumulated energy at peak torque (W hr kg-1). (Figure 2) Water absorption (%) is derived from the peak torque and amount of water added during the test.


Figure 2. doughLAB results

Using a 300g mixing bowl, average precision RSDr and RSDR is <0.3% and <1.5% for water absorption, and <3.1% and <8.1% for mixing parameters (dough development time, stability, softening and energy at peak), respectively. (Dang and Bason, 2013).

doughLAB Advantages

New AACCI method 54-70.01 to measure the mixing properties of dough in the doughLAB using high energy input offers a number of advantages for researchers, flour millers and modern commercial bakeries testing flour and dough. Compared to the traditional low-energy test, new AACCI method
54-70.01 method is:

  • Twice as fast as, providing a full dough mixing curve in 10 minutes.
  • More reliable, with better peak resolution, correctly resolving the dough development peak, and discriminating between very hard flours commonly used for breadmaking that appear similar when tested at 63 rpm.
  • A more reliable indicator of water addition, mixing time, mixing tolerance and other flour performance requirements.
  • Process relevant, producing development times more in line with actual work input in the baking process and providing a superior indication of the flour’s processing needs, commercial baking results and suitability for modern bakeries.

New AACCI method 54-70.01 to measure the mixing properties of dough in the doughLAB is the only approved high energy flour and dough mixing test.

References

Dang, J. M. C., and Bason, M. L. AACCI Approved Methods Technical Committee Report: Collaborative Study on a Method for Determining the Mixing Properties of Dough Using High-Energy Mixing. Cereal Foods World 58:4, 2013.