Reverse Osmosis — Concentration Applications

An examination is made of the influence of the main processing variables in the reverse osmosis (RO) concentration of both whey and skim milk. Up to a solids concentration ceiling of ca. 25 per cent, RO offers an economic advantage over thermal evaporation as a concentration technique, in terms of lower operating costs. Furthermore, RO possesses the additional advantage that it concentrates without heat, thereby retaining the native properties of the original raw material before concentration. In particular, there is no heat denaturation of the thermolabile whey proteins and, hence, no reduction of valuable functional properties and no cooked flavour development. Based on these inherent advantages of RO over thermal evaporation, various process and product applications of RO to whey and skim milk utilization have been suggested. Additional features of membrane processing by RO have also been discussed.