Harnsilawat Thepkunya, Pongsawatmanit Rungnaphar, McClements David J
Department of Product Development, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand, 10900.
Biomacromolecules. 2006 Jun;7(6):2052-8. doi: 10.1021/bm050656q.
Emulsions of 0.1 wt % corn oil-in-water containing oil droplets coated by beta-lactoglobulin (0.009 wt % beta-Lg, 5 mM phosphate buffer, pH 7.0) were prepared in the absence and presence of sodium alginate (0 or 0.004 wt %). The pH (3-7) and ionic strength (0-250 mM NaCl) of these emulsions were adjusted, and the particle charge, particle size, and creaming stability were measured. Alginate adsorbed to the beta-Lg-coated droplets from pH 3 to 6, which was attributed to electrostatic attraction between the anionic polymer and cationic patches on the droplet surfaces. Droplets coated by beta-Lg-alginate had better stability to flocculation than those coated by beta-Lg alone, especially around the isoelectric point of the adsorbed proteins and at low ionic strengths (< 100 mM NaCl). At pH 5, alginate molecules desorbed from the droplet surfaces at high salt concentrations due to weakening of the electrostatic attraction.
在不存在和存在海藻酸钠（0或0.004 wt%）的情况下，制备了含β-乳球蛋白包被油滴（0.009 wt%β-Lg，5 mM磷酸盐缓冲液，pH 7.0）的0.1 wt%水包玉米油乳液。调节这些乳液的pH（3 - 7）和离子强度（0 - 250 mM NaCl），并测量颗粒电荷、粒径和乳析稳定性。海藻酸钠在pH 3至6时吸附到β-Lg包被的油滴上，这归因于阴离子聚合物与油滴表面阳离子斑块之间的静电吸引。与仅由β-Lg包被的油滴相比，由β-Lg-海藻酸钠包被的油滴对絮凝具有更好的稳定性，尤其是在吸附蛋白质的等电点附近和低离子强度（<100 mM NaCl）时。在pH 5时，由于静电吸引减弱，海藻酸钠分子在高盐浓度下从油滴表面解吸。
