There are many key links in the production
process of a flour mill, and each link plays an important role. The control of
each link directly or indirectly affects the quality of flour from different
angles, and the adjustment of water content in wheat affects the quality of the
finished product most. One of the key factors.
There are two different states of water in
food crops: one is free water (also known as free water) and the other is bound
water. Wheat tempering is to increase the free water in the wheat through water
regulation, change the mechanical structure and physical properties of the
wheat grains, enhance the toughness of the wheat cortex, and prevent the broken
wheat husk from being mixed into the flour to reduce the quality of flour.
After moistening, the structure of starch granules in the endosperm becomes
loose and the structural strength decreases, which is beneficial to grinding
and sieving. If the milled wheat has a reasonable and stable moisture, not only
can the quality of the flour be guaranteed, but also the power consumption will
be reduced. Too low moisture in the milled wheat will increase the bran in the
flour, affect the quality of the flour, and reduce the efficiency of the
enterprise; if the moisture is too high, it will be difficult to scrape the
endosperm from the cortex, which will affect the extraction rate and cause
sifting. The hole is blocked, and even the pipeline is blocked, which increases
power consumption and brings difficulties to operation and management.
How can we make the milled wheat have a
reasonable and stable moisture? The author summarized the following points
through the management and operation practice in the flour mill:
1. Distinguish wheat varieties, grasp the
amount of water and time
1.1 Hard wheat
Hard wheat has a relatively high degree of
horniness, a relatively tight protein network structure, and hard wheat has a
relatively large water absorption. Therefore, more water should be added during
the impregnation process to fully soften the endosperm. Due to the compact
structure of the endosperm of hard wheat, the rate of water penetration is
relatively slow. Therefore, the tempering time of hard wheat should be
appropriately extended. It should be 24 to 32 h in winter and 20 to 24 h in
other seasons. . The best ground water content of hard wheat is 15.0% to 17.0%.
1.2 Soft wheat
The endosperm structure of soft wheat is
relatively loose, there are air gaps in the protein network structure, the
combination of starch granules is not tight, and the water penetrates the
inside of the grain faster, and the water added during the impregnation process
can be less. It can also be correspondingly shorter. It should be 20-30 hours
in winter and 16-24 hours in other seasons. The moisture content of soft wheat
should be 14.0%-15.0%.
1.3 Wheat with soft and hard quality
According to the market's requirements for
flour, it is necessary to mix wheat for a lot of time. According to the mix
ratio, the tempering time of hard wheat shall prevail.
2. Determine the target moisture to
moisturize the wheat
2.1 Immersion according to the target
moisture of the finished product
There are national standards for flour, and
various production companies also have corporate standards. Only stable quality
parameters can ensure stable product quality. The moisture in flour products is
also a parameter of flour quality. With the standard to follow, there are also
parameters to follow in operation.
Water content of flour (%) = Water content
of milled wheat (%)-Water loss during processing (%) (wear)
With this calculation formula, the water
wheat has a goal. The moisture content of flour should be 13.6%-13.8% in
summer, and 13.8%-14.0% in other seasons.
2.2 Water loss during processing
In the process of processing wheat into
finished products, some water is lost, commonly known as abrasion. The abrasion
changes according to the process conditions of each production line, the length
of the powder line, the degree of newness of the grinding roller, and the
temperature and humidity of the air. Generally, the moisture loss of wheat
after tempering is 0.5% to 1.2% during the process of processing into finished
products. If the roller temperature is high and the air is dry, the water loss
will be too much; otherwise the water loss will be lower; the water entering
the mill will be higher and the water loss will be higher.
3. Strengthen the follow-up test while in
the water
It is necessary to strictly adhere to the
follow-up test when the water is in the water. Without a detailed test result,
it is impossible to guide and adjust the water volume. It is best to sample
once every hour, and the result of each test of moisture should be 0.2% of the
target moisture. It is best to use a tunnel type moisture analyzer to test the
moisture content of water wheat, because the tunnel type moisture analyzer is
quick to do, and the test result can be obtained in 15-20 minutes. Once the
water is found, it will be unstable. The situation is convenient for timely
adjustment. Only in this way can the milled wheat have a balanced and stable
moisture and ensure the quality of flour.