Riddet Institute, Massey University, Palmerston North 4442, New Zealand.
Colloids Surf B Biointerfaces. 2010 Jun 15;78(1):24-9. doi: 10.1016/j.colsurfb.2010.02.001. Epub 2010 Feb 10.
The heat-induced changes in the surface protein compositions and concentrations of whey protein isolate (WPI)-stabilized emulsions were examined. With increasing heating temperature, the amount of adsorbed beta-lactoglobulin (beta-lg) increased whereas the amount of adsorbed alpha-lactalbumin (alpha-la) decreased. In emulsions formed with 0.5 wt% WPI, the adsorbed alpha-la almost disappeared from the interface of the emulsion droplets after heating at 121 degrees C. With heat treatment at 90 degrees C, adsorbed beta-lg increased but adsorbed alpha-la decreased in the first 5 min, and then changed slightly with increasing heating time. This change in the proportions of beta-lg and alpha-la at the interface may have arisen from the displacement of alpha-la from the interface by beta-lg in the aqueous phase. The addition of NaCl resulted in an increase in the total surface protein concentration during heat treatment, but the competition between beta-lg and alpha-la at high temperatures was eliminated. The emulsions lost stability because bridging flocculation of the emulsion droplets occurred during heat treatment in the presence of NaCl (>50 mM).
研究了乳清蛋白分离物（WPI）稳定乳液的表面蛋白组成和浓度在受热时的变化。随着加热温度的升高，吸附的β-乳球蛋白（β-lg）的量增加，而吸附的α-乳白蛋白（α-la）的量减少。在 0.5wt% WPI 形成的乳液中，在 121°C 加热后，乳液液滴界面上几乎没有吸附的α-la 存在。在 90°C 的热处理下，在最初的 5 分钟内，吸附的β-lg 增加，而吸附的α-la 减少，然后随着加热时间的增加略有变化。界面处β-lg 和α-la 比例的这种变化可能是由于β-lg 在水相中取代了α-la 而引起的。添加 NaCl 导致在热处理过程中总表面蛋白浓度增加，但在高温下β-lg 和α-la 之间的竞争被消除。由于在存在 NaCl（>50mM）的情况下热处理期间乳液液滴发生桥接絮凝，乳液失去了稳定性。
