Milk protein co-precipitates (MPCP) are rich in milk proteins but rejected globally owing to their poor solubility. The investigation was aimed to prepare MPCP with enhanced solubility via modification of their existing production method. MPCP was manufactured from pasteurized cow skim milk (PCSM) by spray-drying calcium lactate-induced co-precipitate dispersion. The conditions for the preparation of coagulum (gel point-T_g, holding time and coagulation time) and for efficient spray drying (pH of feed solution and inlet air temperature) were optimized. PCSM containing 0.5% calcium lactate incubated at 30°C/15 min and heated at 80°C/20 min, exhibited maximum protein recovery (92%) in the coagulum. The coagulum was diluted with distilled water (1:1.4, curd: water), and feed characteristics were optimized for spray drying. MPCP powders obtained from feed solution (adjusted to pH 6.7 with disodium hydrogen phosphate) spray-dried at an inlet temperature of 160°C and outlet temperature (~60°C) demonstrated maximum solubility of 39.57% with a protein content of 78.99%.

Novelty impact statement

This trial successfully achieved ~80% of protein content in MPCP with solubility of ~40% using a lower level (<0.132%) of calcium chelator (DSP). This enhances the potential of MPCP as an ingredient in various food formulations. MPCP can be a potential ingredient in bread and bakery industry as well as dairy industry in cheese formulations; high protein yoghurt formulations etc.