The Solubility of Whole Milk Powder as Affected by Protein Stabilizers and by Emulsifiers

Abstract

The addition of salts for protein stabilization has been practiced extensively by the evaporated milk industry for about 25 yr. The work of Sommer and Binney (10) and Sommer and Hart (11) contributed a great deal toward solving the problem of heat stabilization of the proteins in evaporated milk. The use of sodium citrate in small amounts also has been suggested by Wilster et al. (12) as a means of improving the solubility of milk powder. Josephson and Reeves (6) employed a mineral-ion-exchange treatment of milk to obtain the desired salt balance. A portion of the Ca was replaced with Na by means of a synthetic resin column to produce a heat stable evaporated milk. Controlled pancreatic digestion in milk was introduced by Anderson (1) as a means of preventing oxidized flavor in market milk. Since the pancreatic enzymes break down the protein, it seemed desirable to study their effect on whole milk powder as a combination antioxidant and protein stabilizer. The use of emulsifiers in dairy products has been limited mainly to the ice cream industry as whipping aids. However, other food industries have made extensive use of these agents. In this study, emulsifiers of different hydrophiliclyophilic balance were used with the idea of reducing the surface tension between the milk powder and the water for improved reconstitution. Also, information as to their effect, if any, on keeping quality of the milk powder was desired.