Milk protein concentrate (MPC) powders are high-protein, innovative dairy ingredients. Buffalo milk naturally contains higher concentrations of casein and calcium, which have adverse effect on solubility of MPC powders. Therefore, this study was undertaken to investigate the effect of Sodium triphosphate (STP) and Sodium hexametaphosphate (SHMP) addition in ultrafiltered retentate on physicochemical, functional and reconstitution properties, morphological characteristics and rheological behaviour of the resultant powder. Pasteurized buffalo skim milk (PBSM) was concentrated by ultrafiltration (UF) process to obtain 2.53 × UF retentate (2.53 × UFR) with 0.61 protein to total solids (TS) ratio. Compared to PBSM, ultrafiltration significantly increased (p < 0.05) calcium, protein and TS contents of 2.53 × UFR, but significantly decreased (p < 0.05) its heat stability. Addition of STP-SHMP mixture in 2.53 × UFR noticeably improved the solubility, flowability, water binding, oil binding, foaming capacity, foam and thermal stability and, viscosity of treated MPC60 powder over control powder. The DeBroukere (D43) mean, d50, specific surface area, span and water activity values of treated MPC60 powder were 94.96 ± 0.05, 78.33 ± 0.04 µm, 715.93 ± 0.29 m2 kg-1, 1.97 ± 0.01 and, 0.26 ± 0.01, respectively. Scanning electron micrograph showed the presence of different size powder particles without clustering. Rheological modelling of the reconstituted solution of treated MPC60 was very well described by Herschel-Bulkley model. Overall, this study established that addition of STP-SHMP salts mixer in 2.53 × UFR could improve the solubility of resultant buffalo milk based MPC60 powder.
Keywords: Buffalo milk protein concentrate (MPC) 60; Functional properties; Rheology; Sodium hexametaphosphate; Sodium triphosphate.
© Association of Food Scientists & Technologists (India) 2020.