Optimization of Ultrafiltration Membrane Separation Technology and Characterization of Peptides from Bovine Bone Marrow

Salt extraction and Ultrafiltration membrane (UFM) separation technology of bovine bone marrow protein (BBMP) were optimized, and the structures of proteins and peptides, as well as biological activities were evaluated. The maximum protein content and yield obtained were 57.40 mg/mL, 56.80% respectively by salt extraction under the following conditions: concentration 0.5 mol/L, extraction of 2 times per 3 h; temperature, 45 °C. Maximum membrane flux and protein content reached to 25.29 L/(m 2 h), 76.9 mg/mL using UFMs method optimized by the response surface methodology (RSM) at 10 kDa membrane, operation pressure 0.20 MPa; concentration rate 5, and temperature 40 °C. Among them, the 3 kDa permeate part has the highest radical scavenging capacity against DPPH and hydroxyl free radicals (41 ± 0.20%, 53 ± 0.35%, respectively). These isolated parts were characterized by Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM), atomic force microscope (AFM), sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), and Liquid chromatography-Mass spectrometer-Mass spectrometer (LC–MS/MS). The key functional groups, molecular weight, and mass data accordance with the UFM separation results. Therefore, the separation of protein and peptides with different molecular weights can be achieved by UFM. This study can provide technical support for the full utilization and scientific application of BBM resources, as well as the technical and theoretical foundation for the development of peptides for potential health foods or drugs supplementary materials.