The manufacture of Domiati cheese by ultrafiltration (UF) processing of recombined milk bas been described in several reports (El-Shibiny et al. 1982; Bogaard, 1986). This method has several potential advantages in areas short in milk production. In Egypt, a new plant has been established recently for the manufacture of Domiati cheese on the basis of this technology.
The behaviour of fresh pasteurized skim milk during UF has been described (Glover, 1971; Setti & Peri, 1976; Patel & Reuter, 1985; Chiang & Cheryan, 1986). Similar studies are lacking for reconstituted skim milk or recombined milk. Skim milk powder is usually subjected to variable heat treatments during processing which are known to affect its properties. These heat treatments have been used as a basis for classification of skim milk powders. Therefore, studies on UF of reconstituted milks previously subjected to different heat treatments would be important in the adaptation of this technology to cheese manufacture.
We describe here results obtained for permeation rates of reconstituted skim milk during UF compared with fresh pasteurized skim milk.