Casein is the main protein in mammalian milk, including cow, sheep and human milk. Milk protein is mainly casein, while human milk is mainly albumin. Casein is a kind of large, hard, dense curds that are very difficult to digest and decompose. Casein is the protein with the highest content in milk, which is currently mainly used as food raw materials or microbial culture media. The casein phosphopeptides prepared by Chemicalbook using protein enzymatic hydrolysis technology can prevent the loss of minerals, especially its functional characteristics of promoting the efficient absorption of major elements (Ca, Mg) and trace elements (Fe, Zn, Cu, Cr, Ni, Co, Mn, Se), making it a "mineral carrier", It can combine with metal ions, especially calcium ions to form soluble complexes.