Protein
Content
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Protein
content in flour or wheat with Nitrogen
Analyses (CNA).
Method
: A sample of flour or ground wheat
(0.15 to 0.20 grams) is weighed and
placed into a CNA protein analyzer.
This process is automated and begins
by dropping the sample into a hot oven
where it is burned at 952 degrees Celsius.
The amount of nitrogen released during
burning is measured and a formula is
applied to convert the measurement to
protein content in the sample.
Results:
Protein content is determined
through high temperature combustion
in a protein analyzer. Since protein
is the major wheat compound that contains
nitrogen, the protein content can be
determined by measuring the amount of
nitrogen released during burning. Protein
content results are expressed as a %
of the total sample weight; for example,
10 % protein content on 12 % moisture
basis for wheat or 8.5 % on 14 % moisture
basis for flour.
Why
is this important? Protein
content is a key specification for wheat
and flour purchasers since it is related
to many processing properties, such
as water absorption and gluten strength.
Low protein content is desired for crisp
or tender products, such as snacks or
cakes. High protein content is desired
for products with chewy texture, such
as pan bread and hearth bread. Bakers
use protein content results to anticipate
water absorption and dough development
time for processes and products, because
higher protein content usually requires
more water and a longer mixing time
to achieve optimum dough consistency.
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Ash
Content
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Ash
content in flour or Wheat
Method
: Flour or ground wheat (3/5 grams) is
weighed and placed in an ash cup, then
heated at 585 degrees Celsius in an ash
oven until its weight is stable (usually
overnight). The residue is cooled to room
temperature and then weighed.
Results
: Ash content is determined by high temperature
incineration in an electric muffle furnace.
When a sample is incinerated in an ash
oven, the high temperature drives out
the moisture and burns away all the organic
materials (starch, protein, and oil),
leaving only the ash. The residue (ash)
is composed of the non-combustible, inorganic
minerals that are concentrated in the
bran layer. Ash content results for wheat
or flour ash are expressed as a percentage
of the initial sample weight; for example,
wheat ash of 1.58 % or flour ash of 0.52
%. Wheat or flour ash is usually expressed
on a common moisture basis of 14 %.
Why
is this important? Millers need
to know the overall mineral content of
the wheat to achieve desired or specified
ash levels in flour. Since ash is primarily
concentrated in the bran, ash content
in flour is an indication of the yield
that can be expected during milling. It
also indicates milling performance by
indirectly revealing the amount of bran
contamination in flour. Ash in flour can
affect color, imparting a darker color
to finished products. Some specialty products
requiring particularly white flour call
for low ash content while other products,
such as whole wheat flour, have a high
ash content.
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Using
Sprouted flours in bread making
Falling
Number
The
Falling Number
method was first described by Hagberg
and Perten in the early 1960's for the purpose
of providing a rapid means of determining the
extent of sprout damage in wheat or rye (Doty,
1980). It has found widespread acceptance because
of its rapid analysis time, simple operation,
and high degree of reproducibility (Pyler, 1986).
Sprout damage in wheat is of critical concern
if the end-use for the flour being milled is
bread production. As little as 5% heavily sprouted
wheat in a mill mix of otherwise sound grain
can make the mixture unacceptable for bread
production (Perten, 1985). The
Falling Number Test, an internationally standardized
method, measures the alpha-amylase enzyme activity
in flour to determine how much sprout a grain
has achieved and to assure the grain has not
been drowned. While a lower falling number indicates
high enzyme (sprouting) activity, it is very
important to compare the falling number prior
to sprouting with the falling number after sprouting
to accurately measure how much sprout action
has occurred. A grain that started with a falling
number of 350 and is now 150 has sprouted more
completely than a grain that started at 250
and is now 150. To assure that Breadlink Sprouted
Flours contain the highest sprout action, our
sprouted flours must always have a final falling
number equal to or lower than half of the falling
number prior to sprouting. High quality grain
that has been sprouted and stabilized resulting
in a low falling number is very difficult to
achieve so beware of anyone making claims without
documentation.
Sprouting
in wheat results in a higher than normal
level of alpha-amylase in the flour. Wheat that
has been harvested before sprouting has occurred
contains low levels of alpha-amylase (Posner,
1997). Alpha-amylase
is of greater concern in bread production than
ß-amylase for four reasons: (1) it is
able to hydrolyze damaged raw starch; (2) it
has a higher thermal stability allowing it to
act on gelatinizing starch for 3-4 minutes when
the interior of the bread loaf is 140-150F,
(3) it is stable at the common pH of bread dough:
5.0 - 5.6, and (4) it is activated by calcium
ions that inactivate ß-amylase (Pyler,
1986). In addition to this, ß-amylase
is only able to act upon the non-reducing ends
of starch chains from which it splits off maltose,
and it is unable to act upon intact raw starch
(Doty, 1980). The activity of ß-amylase
is also dependent upon the level of starch damage
in the flour as damaged starch has more sites
at which ß-amylase can act. Starch is
damaged in the milling process and typically
accounts for around 8% of the total starch in
hard wheat flours (Pyler, 1986).
a-amylase
is far more able to reduce the long starch molecules
into smaller pieces upon which the ß-amylase
can act. a-amylase is able to act upon interior
portions of the starch molecules. The result
of this is that the ß-amylase now has
more open sites upon which is can act and produce
more maltose molecules: a source of energy for
yeast involved in fermentation. It is the combined
action of these two molecules that can convert
nearly the entire starch molecule into fermentable
sugar (Doty, 1980)
This
amylolytic action in dough occurs once the dough
ingredients are combined and mixed. The conversion
of starch to maltose and other yeast fermentable
sugars is critical to the bread baking process.
This conversion results in several changes in
dough properties including: a decrease in absorption
capacity, a slackening of dough consistency,
and the development of a stickier dough. The
rate at which these changes occur is directly
proportional to the amount of starch damage
and a-amylase level of the flour. As we noted
above, flour milled from sound, un-sprouted
wheat has a very low amylase content and requires
supplemental a-amylase to have the required
functional properties for bread production.
Hard wheat flours typically have a total sugar
content of 1.5%. This level is initially boosted
to 2.0 to 2.5% during mixing by the rapid action
of a-amylase upon the damaged starch (Pyler,
1986).
Typically,
wheat is harvested once the grain has dried
to an appropriate moisture level that takes
into consideration both optimality for harvest
and suitability for prolonged storage. In a
dry, normal growing season this is done before
the grain has had a chance to germinate and
sprout. The direct implication of this is that
alpha-amylase levels are typically quite low
and supplementation of the milled flour must
occur. The Falling Number Method is used to
measure the level of alpha-amylase activity
in newly harvested wheat as a means of detecting
sprout damage and as a method for determining
the proper
supplementation rates of barley malt, or other
alpha-amylase enrichment (Doty, 1980).
Bread
flours with normal diastatic activity (milled
from sound, un-sprouted wheat and supplemented
with alpha-amylase through the addition of barley
malt, or fungal amylase) typically having falling
number values in the range of 220 to 250 seconds.
Flours deficient in diastatic activity will
typically have values in excess of 400 seconds
and over supplemented flours or flour milled
from sprout damaged wheat can have the minimum
value of 60 seconds.
The
Falling Number Method is based on the starch
liquefying action of alpha-amylase and expresses
this as the time in seconds required to stir
and allow the stirrer to fall a measured distance
through a heated aqueous flour gel that is undergoing
liquefaction (Pyler, 1980). The instrument consists
of a boiling water bath, a stirring head, and
a timer. Also needed are, a test tube and a
stirring rod. The stirring head consists of
motors and gears which allows for precise and
uniform stirring insuring reproducibility of
the results (Doty, 1980).
The
procedure for flour involves mixing 7 g of flour
with 25 mL of distilled water in a test tube.
The tube is shaken and the stirring rod is inserted
and then the whole assembly is placed in the
boiling water bath. The timer is automatically
started and a stirring process is activated
and continues for 55 seconds and a rate of 2
strokes per second. At the end of 60 seconds
the stirring rod is released from the up position
and allowed to fall through the heated flour-water
slurry. Upon completion of the vertical fall
the timer stops and displays the elapsed time
in seconds (Pyler, 1986). The descent of the
stirring rod through the slurry is related to
the amylase activity of the sample. Upon completion
of the stirring action the amylase present in
the flour starts to break down the gelatinized
starch reducing the viscosity of the slurry
(Doty, 1980).
If
analysis of a wheat sample is required then
a 300 g sample is ground in a hammer mill to
obtain a flour sample. From here the procedure
is the same as above for the flour sample (Doty,
1980).
There
are several factors that have the potential
to affect the results of the Falling Number
Method. These include the sampling method, the
preparation of the samples, moisture content
of the samples, boiling temperature (affected
by altitude), heat treatment of the grain, and
the stirring procedure (Perten, 1967). This
last issue is not of particular importance today
as the Falling Number Instruments most commonly
found are fully automated and require little
operator input aside from the initial shaking
of the sample.
The
falling number method as described is an absolutely
essential analysis technique in both the milling
and baking industries. As alpha-amylase plays
such a critical role in baking, the development
of this rapid, simple, and highly reproducible
technique has proven to be invaluable.
Flour
: Basic infos
A
basic and indispensable food staple, can vary
in quality and nutrition depending on the type
of grain and the milling process used. Baking
and cooking with a variety of whole grains adds
nutrition to your meals.
The
milling process affects the nutritional
value and quality of the flour. Lower heat methods
result in a nutritionally superior flour. Stone
ground flour is milled by a slow process using
granite stones, often powered by water which
scatters the bran evenly through the flour and
keeps the flour cooler than when ground with
steel rollers. Although stone ground whole wheat
flour is still available, most grains today
are machine milled, with superior results.
Most
of the whole grain flours sold in co-ops are
milled by an impact or “hammer mill”
that generates almost no heat so the grains
do not get scorched. Our flour comes from companies
that well-respected the milling high-quality
products.
After
milling, some flours are refined. The
refining process strips away the fiber-rich
bran and the germ which contains valuable vitamins
and minerals. White flour can be made from refined
whole wheat flour.
Flours
labeled as wheat instead of whole wheat are
often refined. Some refined flours have been
enriched. This sounds a lot better than it is.
Of the 22 nutrients that are lost in the refining
process, only five are added back in the enrichment
process. Whole grain flours are not refined
and contain all of their valuable nutrients.
Bread
Machines are convenient bread baking
devices that allow you to have fresh, homebaked
bread. A good place to start for making a whole
grain loaf with your bread machine is to use
one of the many bread mixes we carry. But remenber
always to do a slow, low temperature proving.
If
you want to make whole grain breads or even
sprouted, be sure to buy the correct machine.
It may be difficult to get a decent wheat-free
bread from a machine. If you don’t use
wheat, you may wish to continue making your
bread by hand. A machine will never have a feel
for working the dough, and therefore will not
be able to make adjustments in kneading that
can be made when bread is made by hand. Be aware
that some machines can only produce loaves from
white flour or a white and wheat combination.
People
with Gluten Sensitivity All forms of
wheat, barley, kamut, oats, rye, spelt and triticale
contain gluten. Amaranth has minute traces of
gluten. All other grains and flours do not contain
gluten if processed in a gluten-free environment.
Note also that , as explainned in our pages,
the gluten is damaged and transformed by the
sprouting. Although present, its transformation
is radical. So much so that we have exemple
of people allergic to gluten that can eat our
sprouted flours .
Wheat
Flours made from wheat are the most
common. Wheat contains the most gluten. Gluten
is a protein found in some grains that helps
bread rise and keep its shape. Flours with more
gluten make better breads.
All-purpose
flour is a blend of whole wheat bread
flour and whole wheat pastry flour. This makes
it a good choice for any of your baking needs.
Durum
flour is ground from durum wheat, the
hardest wheat grown. Semolina is refined durum
flour. It is the flour commonly used for making
pasta. The bran and germ have been removed by
an airsifting process, giving semolina pasta
its characteristic light color.
Gluten
flour is made from hard wheat that
has been treated to remove some of its starch
and concentrate its protein. Gluten flour contains
at least 70 percent pure gluten. It can be added
to low-gluten flours to lighten the loaf. This
is a highly refined flour and should be used
sparingly to improve bread rising capabilities.
Graham
flour named after Sylvester Graham,
an early crusader against commercial white bread,
is a coarse ground whole wheat flour. Used alone,
it produces a heavy, compact, dark bread.
Unbleached
white flour is highly refined. Although
it has not been bleached, most of the nutrients
have been removed during the refining process.
Unbleached white flour is unfornunately popular
because of its versatility. It can be used for
breads, pastries, cookies or cakes.
Whole
wheat bread flour or hard whole wheat
flour is ground from hard red spring or hard
red winter wheat berries, and is the best for
making breads and rolls. Whole wheat pastry
flour or soft whole wheat flour is milled from
soft winter wheat berries, a different variety
of wheat than the one used for bread baking.
It has the ability to hold a lot of fat, and
is ideal for pastry and cake making. Breads
made with whole wheat pastry flour will not
rise.
Other
Flours come from many sources including
grains, legumes, starchy vegetables, nuts and
carob, but each has its own baking properties
and uses.
