Delactosed, High Milk Protein Powder. 2. Physical and Functional Properties

¹ Minnesota-South Dakota Dairy Foods Research Center, Dairy Science Department, South Dakota State University, Brookings 57007-0647

The objective of this research was to examine some physicochemical properties of a novel delactosed, high milk protein powder. Data indicate that the solubility index of the powder was dependent on temperature of mixing. Solubility index decreased (solubility increased) as temperature increased from 25 to 60°C. Foaming capacity, expressed as percentage overrun, was low at pH 7 and 8 but increased at higher pH, e.g., after 10 min of whipping, overrun increased from 470 to 941% as pH increased from 7 to 10. Foaming increased with time at higher pH but not at lower pH. Particles of the high milk protein powders as examined by scanning electron microscopy were characterized by smooth surface and dents. Particles of skim milk powder prepared in the same spray dryer had a wrinkled surface. Commercial casein products had a structure similar to that of the high milk protein powders.

Key Words: protein • powder • properties • microstructure

Submitted on March 1, 1991
Accepted on May 31, 1991