Effects of pH and concentrations of colostrum whey and caseinate on fabrication of nanoparticles and evaluation of their techno-functionalities and in vitro digestibility

Intermolecular interactions between colostrum whey and sodium caseinate were studied in aqueous medium under different pH conditions (3–7) using dynamic light scattering (DLS) technique. The surface charge density of casein was modified through pH adjustment to increase the interaction between casein and whey protein. The stable nanoparticles (NPs) with mean hydrodynamic diameter of <125 nm was prepared by mixing sodium caseinate and colostrum whey protein at pH 6.5. The effects of pH (3–7), ionic strength (50–300 mM of NaCl 2 ) was studied on the stability of particles. The differential scanning colorimetry showed that the thermal stability of NPs was higher (128.3 o C) compared to their native proteins. NPs in liquid form at 25 °C showed remarkable stability up to 1 month. The FTIR assay confirmed that the secondary structures of the whey proteins remained unaltered. Furthermore, the Scanning Electron Microscopy (SEM) displayed the spherical shape of the nanoparticles in exquisite detail. The in vitro study of NPs indicated that the recovered Igs content was higher in NPs (IgG 68%, IgA 14.5%, and IgM 19.5%) as compared to control (IgG 42.7%, IgA 9.7%, and IgM 14.4%). Colostrum whey-based NPs can be used as a dietary supplement to deliver nutrients and growth factors to the body and can have various health benefits, such as improving immunity, promoting wound healing, and enhancing athletic performance.