Milk protein concentrates 80: Does composition of buffalo milk matter for its poor functionality?

Abstract

Poor solubility is the major problem in high-protein milk protein concentrates (MPC). Therefore, present investigation aimed at producing and characterizing buffalo milk-based milk protein concentrate 80 (BM-MPC80) for its physicochemical, functional and reconstitution properties; morphological characteristics and rheological behaviour. The UF concentrate (0.80 protein to total solids ratio) obtained through ultrafiltration (UF) of pasteurized buffalo skim milk was spray-dried at 200/95 ± 5 °C to obtain BM-MPC80 powder. It was observed that solubility (24.40 ± 0.84%), heat stability (1.00 ± 0.00 min), porosity (34.90 ± 1.20%), dispersibility (7.43 ± 0.26%), specific surface area (36.60 ± 1.59 m2/kg) and flowability (43.56 ± 1.69°) values of BM-MPC80 powder were lower than counterpart. Its particle density, dispersion index, wettability, water activity, apparent viscosity (at 20 °C, 50 s−1), foam capacity and stability values were 0.56 ± 0.02 g/mL, 1.20 ± 0.89%, 6.33 ± 0.32s, 0.12 ± 0.00, 0.455 ± 0.00Pas, 36.27 ± 1.56%, and 70.53 ± 1.34%, respectively. Scanning electron micrographs revealed extensive aggregation in BM-MPC80 powder particles, which could be responsible for its poor solubility and dispersibility. Shear-thinning behaviour was observed in UF concentrate and reconstituted BM-MPC80 solution. Overall, this study established that composition of buffalo milk is responsible for poor functional and reconstitution properties of BM-MPC80 powder.