Farming Knowleagde

The factors affecting granulation include the source of raw materials, the moisture in the raw materials, the content of starch, protein, fat, crude fiber, bulk density, structure and particle size of the materials.
1. Particle size: The powder is pulverized to be fine, which is beneficial to the progress of hydrothermal treatment. On the contrary, the coarse-grained powder has low water absorption capacity and poor quenching and tempering effect.
2. the bulk density: the bulk density of the material has a direct impact on the output. When the same granules are produced and the material with a large volume is granulated, the output is high and the power consumption is small. On the contrary, the output is low and the power consumption is large.

3. the impact of chemical composition of materials
1) Starch: Different forms of starch have different effects on granulation. The raw starch microparticles have a rough surface and a large resistance to granulation. When the raw starch content is high, the granulation yield is low and the stamper wear is severe. Raw starch particles have poor binding ability to other components, and the final product is loose. The cooked starch, that is, the gelatinized starch, is quenched and hydrated and then exists as a gel. The gel facilitates the passage of the material through the die hole, thereby improving the granulation yield. At the same time, after the gel is dried and cooled, it can bond other components around it to make the granular product have better quality. During the quality process, the starch granules are viscous after being steamed and partially damaged and gelatinized by the compression molding and pressing rolls, so that the prepared granules are precise in structure and quality. In addition to the structure and properties of various starches, it is also related to the fineness of the powder. Therefore, when corn and sorghum are the main raw materials, the particle size should be pulverized before granulation
2) Protein: The protein is heated and deformed to enhance the adhesion.
3) Grease: The oil and fat inherent in the raw material does not cause the oil to be squeezed out due to the temperature and pressure during the granulation process, so the effect on the granulation is not great, and the added oil has obvious yield and quality to the granulation. influences. Adding 1% of the oil to the material will soften the granules, and will significantly increase the granulation yield, which will reduce the wear of the stamper and the press roll. However, the raw material has a high oil content before granulation, and the obtained granules are loose. The amount of fat added before granulation should be limited to 3%.
4) Molasses: usually added in an amount less than 10%, which can be used as a binder, which is beneficial to the hardness of the reinforced particles, and the effect depends on the ability of the material to absorb the molasses.
5) Cellulose: There is no cohesive force in itself, but if the fiber is too much, the resistance is too large, the yield is reduced, and the die wear is fast. The material with high crude fiber content is loose and porous inside, and should be controlled to mold moisture. If the moisture is too high and the temperature is high, the particles will expand rapidly after being released from the mold and are prone to cracking.
6) Heat-sensitive raw materials: When adding certain vitamins, seasonings and other materials that are subject to heat and damage, the granulation temperature should be appropriately reduced and added in excess to ensure the effective content of these ingredients in the finished product.

4. Binders Some starches, proteins or other components with binding effects contained in some feeds are difficult to prepare. Therefore, a binder is required to achieve the desired degree of solidification of the particles.
What are the physical and chemical changes in protein, carbohydrates, fats and vitamins during the granulation process:
Physical changes in protein: The protein will exhibit a tendency to reduce the water solubility of the protein. The water content of the different varieties of raw materials will be different under the granulation conditions due to the difference in protein content. The general trend is that the higher the protein content, the more the water solubility decreases. The second is the ambiguity. The greater the ambiguity, the smaller the water solubility of the protein.
Changes in chemical properties: The protein is gradually reduced, and the hydrolysis time of the protein in the digestive tract is reduced. The protein content is basically unchanged throughout the process, and the amino acid stability and titer are not significantly reduced.