Effect of calcium sequestering salts on the physicochemical, rheological and functional properties of buffalo milk micellar casein concentrate

The present study investigated the effect of adding calcium sequestering salts (CSS) namely sodium hexametaphosphate (SHMP) and trisodium citrate (TSC), to microfiltered retentate of skimmed buffalo milk (MFR-SBM) on the reconstitution, functional and structural properties of micellar casein concentrate (MCC) prepared therefrom. MFR-SBM was added with 30 mEq/kg SHMP or 30 mEq/kg TSC prior to spray drying and obtained samples were coded as BM-SHMP-MCC and BM-TSC-MCC, respectively. The protein content of all the MCC samples ranged from 70.15 to 72.61%. BM-SHMP-MCC and BM-TSC-MCC had 2–2.75 times higher viscosity, reduced interstitial air and higher occluded air than BM-MCC. BM-MCC had a solubility of 27% which increased to 40% for BM-TSC-MCC and 45% for BM-SHMP-MCC. BM-TSC-MCC had higher emulsification capacity than BM-MCC, whereas BM-SHMP-MCC had the highest emulsification stability. Foaming capacity of BM-MCC increased significantly ( P < 0.05) on addition of CSS to MFR-SBM. Fourier Transform Infrared (FTIR) spectroscopy indicated reduced β-sheet structure and increased random coils, α-helix and β-turns showing higher disordered structure due to CSS-induced micellar dissociation. The incorporation of SHMP and TSC effectively modified the structure and improved the solubility and foaming properties of BM-MCC. The findings of the present study would allow industries to manufacture MCC with desirable functional properties.