World Grain - June 2010 - 56

TECHNICAL PROFILE: PREDICTING PERFORMANCE OF FLOUR BLENDS

usually limited to either the mixing or
end-use quality of bread flour, ignoring
the use of flour to manufacture other
products.
Thus it is necessary to develop new
specific tests that better predict quality
and processing characteristics.
A NEW QUALITY TESTING METHOD
The doughLAB and its small (4 gram)
sample-size version, micro-doughLAB,
are relatively new instruments to measure the water requirements and doughmaking properties of wheat flour. The
doughLAB incorporates an automated
dispenser and variable temperature and
speed control systems, providing users
with the flexibility to emulate modern
high-energy mixers, multi-stage mixing, chilled dough systems and heating
of dough.
Emulating commercial high-energy/high-speed mixing conditions.
The doughLAB was designed to emulate the high work rates of modern
dough mixers, able to deliver up to
60 kilojoule/kilogram/minute (kJ kg-1
min-1 ) when mixing at 150 rpm in its
300-gram mixing bowl, developing a
typical pan bread dough in about 2 to
3 minutes. This is similar to the work
rate and dough development time for
high-speed commercial dough mixing for production of bread and related
products such as bagels, soft pretzels
and pizza crust.
Emulating chilled mixing conditions. Modern bakeries employ high
energy and low temperatures in the production of raw and pre-cooked frozen
dough products. Fitted with a chiller,
the doughLAB is capable of test temperatures down to 10 degrees C. This
method can be used to mimic production conditions for hard, soft, and whole
meal flours and full bread formulations.
Emulating two-stage mixing of formulations with fat. A two-stage mixing method has been developed to assess high fat formulations used for laminated products such as brioche. In this
case, a low-speed mixing (63 rpm) step
is used first to blend the ingredients,
www.World-Grain.com / World Grain / June 2010

followed a by high-speed (110 rpm)
step to develop the gluten network.
Dough with ingredients and full
formulation dough. Tests have been
developed to monitor dosage effects of
additives that modify mixing properties, such as dough conditioners, reducing agents, amylases and sugars.
Monitoring commercial dough
consistency. To help avoid dough-handling problems in bakeries, dough can
also be taken directly from commercial
mixers and its consistency measured in
the doughLAB.
Low-water (crumbly) dough for
pasta, pastry, cookies, crackers,
noodles and wanton wrappers. Lowwater (down to 30%) dough may also
be tested in the doughLAB. High-speed
(180 rpm) mixing is used to test samples for suitability in biscuit (cookie),
cracker, noodle, pasta, pastry (pie
crust) and wanton wrapper production,
mixing at torques around 7.8 nanometers (800 FU), yielding energy input
rates around 18 kJ kg-1 min-1.
Estimating energy input. The area
under the doughLAB graph to the time
of the dough development peak indicates the mixing energy requirements
of the flour. By knowing this, the baker
knows how much energy to add to the
flour during mixing and how cold the
added water must be to give the correct
temperature for proofing after mixing.
REDUCING COST,
MAXIMIZING PROFITS
The doughLAB and micro-doughLAB, with their software package,
doughLAB for Windows (DLW), provide flour millers with a tool to assist
their blending operations by predicting
the functional performance of a flour
blend before the blend is made.
The software is capable of mathematically combining data from several
doughLAB or micro-doughLAB tests
to predict the effect of blending mill
streams.
DLW software very closely predicts
mixing characteristics of flour blends,
showing a very good comparison be-

tween actual and virtual curves. Thus
the software can be used as a tool for
flour blending applications of individual streams with known mixing characteristics, without the need for producing the blend first. Hence blending
data is potentially a quicker, easier and
more efficient alternative to blending
first and then testing flour samples. The
modelling tool can also be used to do
complex "what if?" analyses without
having to run lots of tests.
This feature is especially useful for
millers to reduce costs and maximize
profits while producing different flour
products for specific customers and
specific uses.
OPTIMIZE SPECS WHILE
MINIMIZING COSTS
Procuring suitable quality flour at
the lowest cost is an important goal of
the flour buyer, but if the flour causes a
problem in processing or end-product
quality, the cost-savings may be insignificant compared to the losses later in
the chain. A receiving plant, especially
if receiving flour from a range of alternative suppliers, over a range of different specifications, even over a range
of different countries, may test each
incoming flour shipment. On this basis,
blends may be designed to maintain
specifications for specific purposes and
products.
Modeling the performance of blends
with DLW software allows their performance to be predicted and offers
a powerful tool for managing crop
changeover issues.
Being able to predict the functional
performance of proposed blends before they are made, using test conditions that model commercial production, enables the lowest cost optimum
blend to be identified by both millers
and buyers.
Bronwyn Elliott is commercial product manager
for Perten Instruments of Australia. She may be
contacted at belliott@perten.com.
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World Grain - June 2010

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