在pH值7.0时以乳清分离蛋白为乳化剂制备初级乳状液,利用静电自组装技术,通过加入具有不同电性的阴离子型果胶、中性瓜尔豆胶、阳离子型壳聚糖制备具有良好稳定性的乳清分离蛋白-多糖的二级乳状液,并考察pH值、乳清分离蛋白与多糖的比例对乳状液稳定性的影响。结果表明:瓜尔豆胶与乳清蛋白乳状液粒子间无静电作用;在pH值5.0~6.0条件下,壳聚糖能够吸附到乳状液粒子表面,但形成的乳状液稳定性较差;在pH值3.0~5.0、果胶质量分数为0.2%~0.5%条件下,乳清分离蛋白-果胶为乳化界面构建的二级乳状液,稳定性最高。
O/W emulsions (pH value 7.0) stabilized by whey protein isolated was prepared as the primary emulsion at first, and then polysaccharides with different electrical properties, e.g. anionic pectin, neutral guar gum, and cationic chitosan were added to the secondary emulsions structure. The influences of pH value, protein and polysaccharide ratio on the formation of protein-polysaccharide muhilayer membranes were investigated. It showed that no electrical reaction between guar gum and emulsion particles could be detected. Chitosan could adsorb to the surface of particles at a pH value 5.0 - 6.0, however, the formed WPI-chitosan secondary emulsions were unstable. Pectin molecules could absorb to the surface of particles and formed WPI-pectin secondary emulsion at the pH value 3.0 - 5.0. Stable WPI-pectin secondary emulsion could be formed at pectin concentration 0.2% -0.5%.