The composition of buttermilk powder and skim milk powder is compared in Table 1 (–> water content). The production of buttermilk powder based on sweet or sour buttermilk is analogous to that of skim milk powder. Sweet buttermilk powder is preferred for applications in the field of functional technology because its quality is more stable.
Because it has a greater residual fat content than skim milk and a increased level of phospholipids with a higher fraction of multiple unsaturated fatty acids, buttermilk powder is prone to oxidation and has only a limited shelf life.
The increased quantities of phospholipids from the fat globule membrane in buttermilk and buttermilk powder impart increased technological functionality to buttermilk powder, particularly powder from ultrafiltered buttermilk. The low-molecular phospholipids are surface-active and therefore able to replace traditional emulsifier additives. More information on this subject can be gleaned from: Eugster E.: Konzentrierte Buttermilch ersetzt Emulgatoren [Concentrated buttermilk replaces emulsifiers]. Schweizerische Milchzeitung. 126, 7–7 (2000). On the basis of work carried out at FAM, the Swiss dairy industry has added powder from ultrafiltered buttermilk to its production range.