THE EFFECT OF HEAT-TREATMENT ON INTRINSIC AND FORTIFIED SELENIUM LEVELS IN COWS MILK

The effects of two heat processing methods (pasteurisation and spray d rying) routinely used in the processing of cow's milk and the producti on of infant formula powder on the selenium (Se) content of liquid mil k, milk fortified with sodium selenite and sodium selenate were studie d. Pasteurisation reduced intrinsic Se and selenate levels by 7.9% and 6.2% at p < 0.05 level and selenite levels by 7.0% at p > 0.05 level. Se losses following spray drying were 44.8% (p < 0.001), 11.4% (p < 0 .01) and 10.0% (p < 0.01) for intrinsic selenium, selenite and selenat e fortified milk, respectively. Total Se losses from unprocessed milk following processing (pasteurisation and spray drying) were 49.2% (p < 0.001), 17.6% (p < 0.001) and 15.6% (p < 0.001) for intrinsic seleniu m, selenite and selenate fortified milk, respectively. (C) 1998 Elsevi er Science Ltd. All rights reserved.