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, i 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.