Abstract:Bovine casein is one of the main protein components of infant formula milk powder. Its phosphorylation level is higher than that of human casein, which limits its direct application in infant foods. In order to make bovine casein closer to human casein at the molecular level, the author considered milk protein concentrate (MPC) as the research object. A series of MPCs with different dephosphorylation degrees were prepared by using potato acid phosphatase (PAP) as the dephosphorylation modification treatment. Urea-PAGE, microwave digestion-UV/visible absorption spectrometry and ultra high-performance liquid tandem mass spectrometry (UPLC-MS) were applied to investigate the changes in dephosphorylation degree. Moreover, the digestibility of dephosphorylated MPC was also investigated using an in vitro digestion model. The results showed that a series of MPC with dephosphorylation rate of 0~85.8% was obtained after the modification of MPC by PAP dephosphorylation. With the increase in dephosphorylation degree, the looser clots were observed, and the gastrointestinal digestibility of MPC increased under in vitro conditions.
