EFFECTS OF HEAT-TREATMENTS AND SUBSEQUENT STORAGE ON THE MINERAL BALANCE OF EWES MILK

The effects of heat treatment of ewes: milk at; 65-85 degrees C for 10 -30 min and subsequent storage at 20 degrees C for 90 min on the chang es in ionic calcium and the distribution of calcium, magnesium and pho sphor us between the diffusible and micellar phases were studied. As m ilk was heated there was a decrease in ionic calcium of similar to 36 mg/l, but there was a rapid 86-90% recovery during the first 30 min af ter heating. Although the rate of reversal on subsequent storage decre ased with the intensity of the heat treatment, there were no significa nt differences between samples after 90 min storage. Similar results w ere obtained for cows' milk subjected to the same treatments. Diffusib le calcium, magnesium and phosphorus in heated samples were lower than in raw milk. Recoveries of initial values decreased with the severity of the heat treatment and were 80-95% for calcium, 85-97% for magnesi um and 87-98% for phosphorus. Heat treatment under milder conditions ( (85 degrees C for 20 s) was associated with almost complete recoveries . Recover ies of the minerals studied were slightly lower in ewes: tha n in cows' milk.