花生蛋白微粒ζ－电位的测定

ξ-POTENTIAL MEASUREMENT OF PEANUT PROTEIN PARTICLES IN EMULSION

应用捣碎、离心分离方法，从去红衣花生仁制取花生蛋白乳状液．使用界面移动法测定花生蛋白微粒在一系列ｐＨ值的花生蛋白乳状液中的ζ－电位和微粒荷电状态，探讨了花生蛋白乳状液在不同ｐＨ值下的稳定性，发现ζ＝０时不是处于特定的ｐＨ值，而是在一个ｐＨ值区间内，从而认为花生蛋白乳状液中最少有两种或两种以上花生蛋白质．

The emulsion of peanut protein was obtained through thefollowing Processes:1)Shell the peanuts and the red skin of the kernels;Soak the peanut kernels in water and grind them;Remove the Sediments such as the unemulsifiable starch,celluloses,hemicelluloses,and the floating fat from the emulsion by centrifuging;Refining.The:ξ-potential of the particles in the emuision was detetmined by moving-boundary method at 28℃.When PH=3.40～5.30,ξ=0;and when pH=3.30～5.72,sediment is obvious in the electrophoretic tube and the protein particles are in an unstable state.When pH is below 3.30,the particles are charged positively electricity.When pH is above 5.72,the particles are charged negatively.Since the isoelectronic point stands in a pH interval and not ata specific PH value,an inference can be drawn that there are two kinds of proteins or mere in peanuts.When Ph=3.30～3.40,or pH=5.32～5.72 sediment takes place with moving of the interfaces and the ξ-potential remains the same.This shows that when the particles with different charges meet each other,they become neutralized and unstable,thus causing sediment,and that there is stilla surplus of particles charged with electricity in the emulsion.