Application of protease in fermented soybean meal

Soybean meal is 12 kinds of vegetable oil meal, such as cottonseed meal, peanut meal, rapeseed meal, etc. It is the one with the largest output and the most widely used in feed. The amino acid balance of soybean meal can meet the nutritional needs of poultry and pigs without the need for additional animal protein. In fact, soybean meal has been used as a benchmark against which other protein sources are compared. However, a large number of anti-nutritional factors in soybean meal reduce the nutritional value of soybean meal and limit its use. Through microbial fermentation technology, combined with the application of enzyme preparations, the cell wall of soybean meal can be destroyed more thoroughly, the content can be released more easily, the content of anti-nutritional factors is low, soybean protein is decomposed into small molecular proteins, and the utilization rate of nutrients in soybean meal is improved.

Fermented soybean meal is fermented incompletely, unevenly, and unstable. It fails to better remove anti-nutritional factors and decompose macromolecular proteins, but it may introduce harmful bacteria (miscellaneous bacteria), and antigenic proteins may be degraded into more antigenic and toxic The fermented soybean meal is a small molecule antigenic protein with greater sexuality, and the soybean meal is fermented and then dried again, which leads to many unsafe problems such as a decrease in the digestibility of nutrients. Therefore, the fermented soybean meal cannot be better improved, but reduces the quality and nutritional value of the soybean meal. The quality of fermented soybean meal is affected by many factors. Some users find that the use of fermented soybean meal instead of soybean meal or other protein raw materials will lead to negative conditions such as diarrhea and decreased growth performance in piglets, and this is also a headache for fermented soybean meal manufacturers.

The use of exogenous protease to inactivate antigenic proteins in soybean is to use neutral protease and acid protease to destroy antigenic determinants, thereby changing the original immune activity of the protein, and the degradation degree is about 40%~45%. When the degree of hydrolysis reaches more than 25%, the antigenic determinant will lose its original antigenic structure and immune activity.

After the soybean protein is hydrolyzed by protease, part of the peptide bond is broken, the structure of the antigenic determinant is destroyed, and a small molecule with no immune activity is formed. The hydrolysis of protease has the advantages of mild conditions and no residue of harmful substances. Protease must be used in conjunction with lactic acid bacteria (yeast, etc.), neutral protease works better in poultry, and acid protease works better in mammals.