For puffed corn used in feed, the most important thing is to require maturation (ie, the degree of gelatinization). As for puffing, it is an inevitable result of starch particle rupture and water flash evaporation. Generally, the bulk density is used to characterize the degree of puffing. Therefore, puffed corn has two requirements, the degree of maturity and the degree of puffing, which are measured by the degree of starch gelatinization and the bulk density of the materials, respectively.
The starch gelatinization degree is determined by the amyloglucosidase method, and the bulk density of the materials can be measured by a bulk density meter. The degree of maturity is related to the degree of puffing. A high degree of maturity does not necessarily mean a high degree of puffing, while a high degree of puffing results in a high degree of maturity. For most feed companies, there is no condition for measuring the degree of gelatinization, but the bulk density is easy to measure, and the maturity reflected by the bulk density is also more accurate. Therefore, the bulk density has become an important index for the evaluation of puffed corn in feed enterprises. According to the bulk density of the final product (after drying and cooling, the 2mm sieve plate is crushed), the puffed corn can be divided into three types:
1. Low swelling products: bulk density> 0.5kg/l, low temperature swelling is generally used, about 80ºC to 120ºC, the finished product has high moisture content, and the degree of gelatinization can reach 60% to 80%. It can be used in post-weaning piglets and can also be used for Multidimensional and enzymatic coating process.
2. Medium puffing products: bulk density 0.3kg/l～0.5 kg/l, temperature 100ºC～150ºC, finished product moisture 8%～10%, gelatinization degree can be more than 90%, used for suckling pig feed and some special animal feed, aquatic feed.
3. High-expansion products: bulk density of 0.1 kg/l～0.3 kg/l, temperature of 140ºC～170ºC and higher, finished product moisture of 4%～8%, can be completely gelatinized, generally dry extrusion is used for compound phospholipids Powder carrier, and foundry industry, coating industry.
Because the effect of moisture on puffed corn is very significant, at the same temperature, the degree of swelling of products with different moisture is also different. The lower the moisture, the higher the degree of swelling, which is directly reflected in the product bulk density. Under the same moisture, the higher the degree of swelling, the higher the swelling temperature, the higher the power consumption, and the lower the yield.
Therefore, you need to determine the appropriate degree of puffing according to your product requirements. For puffed corn for general feed, you must first ensure sufficient maturity and moderate puffing. Excessive puffing will not only cause inefficient equipment, but also produce some new lignin-like substances that are resistant to enzyme digestion, which will cause the starch content of puffed products to decrease or the amount of dietary fiber to increase, thereby reducing the digestion and absorption of starch by animals.
Extruded corn can be used for multiple feed processing. If you want to know more about feed extruder machine， animal feed production line and aquatic feed production line, please contact Richi Machinery for details!
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