Formation of interfacial milk protein complexation to stabilize oil-in-water emulsions against calcium
- 作者：Aiqian Ye ; a.m.ye@massey.ac.nz ; Jerilyn Lo ; Harjinder Singh
- 关键词：Milk proteins ; Lactoferrin ; Oil-in-water emulsions ; Interfacial complexes ; Calcium stability ; Steric repulsion
- 刊名：Journal of Colloid and Interface Science
- 出版年：2012
- 期刊代码：125_00219797
- 类别：ch
- 出版时间：15 July, 2012
- 卷：378
- 期：1
- 页码：184-190
- 文件大小：2699 K
摘要
Oil-in-water emulsions (30%soya oil) stabilized by sodium caseinate or whey protein were destabilized in the presence of calcium, whereas lactoferrin-stabilized emulsion was stable under same conditions. At pH 7, addition of lactoferrin to the caseinate or whey protein-stabilized emulsions led to association of lactoferrin with adsorbed proteins by electrostatic interactions, hence resulted in the formation of lactoferrin-caseins/whey protein interfacial complexes at the interface of the emulsion droplets. The stability of the interfacial complexes-coated emulsion droplets in the presence of Ca2+ was examined by determination of particle size, zeta-potential and microstructure as a function of Ca2+ concentration and added lactoferrin concentration. For emulsions made with 1%w/w caseinate or WPI, the stability of emulsions in the presence of 20 mM CaCl2 has been improved markedly after addition of 0.2%w/w lactoferrin, suggesting the small amount of lactoferrin on the interface can largely enhance the calcium stability of milk proteins-coated emulsion droplets. Steric repulsion between the interfaces of droplets produced by the large lactoferrin molecules on the interface was considered to contribute the preventing the flocculation caused by Ca2+ binding and reduction in the electrostatic repulsion between the emulsion droplets.