School of Chemical and Life Sciences, Singapore Polytechnic, 500 Dover Road, Singapore.
School of Chemical and Life Sciences, Singapore Polytechnic, 500 Dover Road, Singapore.
Int J Biol Macromol. 2019 Oct 15;139:421-430. doi: 10.1016/j.ijbiomac.2019.07.210. Epub 2019 Jul 30.
The present study investigated on the emulsifying properties of natural low-methoxyl pectin (LMP) extracted from Green Jelly Leaf (GJLP) in stabilising lactoferrin stabilised oil-in-water emulsions. The emulsion stability of GJLP was compared to commercial pectins with different degree of esterification (DE) i.e. high-methoxyl pectin (HMP) and LMP. The influence of pH, pectin types and concentration on the stability and physical properties of emulsions were evaluated by determining zeta potential value, particle size, microstructure, rheological properties and creaming stability. Different types of pectin exhibited different mechanisms in providing the emulsion stability and the pectin effective charge was strongly dependent on its DE and pH of the continuous phase. The mechanism of actions of pectin and lactoferrin in the system were pH dependent for low molecular weight pectin, however not for high molecular pectin such as GJLP. The results showed that the complexes formed by pectin and lactoferrin at the interface were not sufficient to maintain the emulsion stability. This study also showed the important of unabsorbed pectin molecules in continuous phase in providing the physical stability of emulsion. These molecules formed a thick multilayers surround oil droplets. In addition, the incorporation of 0.2% w/w of GJLP could produce a stable emulsion, suggesting the potential use of GJLP to improve the stability of lactoferrin stabilised oil-in-water emulsions.
本研究探讨了从绿 jelly 叶（GJLP）中提取的天然低甲氧基果胶（LMP）在稳定乳铁蛋白稳定的水包油乳液中的乳化性能。将 GJLP 的乳化稳定性与具有不同酯化度（DE）的商业果胶（即高甲氧基果胶（HMP）和 LMP）进行了比较。通过测定 Zeta 电位值、粒径、微观结构、流变性能和乳状液稳定性，评估了 pH 值、果胶种类和浓度对乳液稳定性和物理性质的影响。不同类型的果胶在提供乳液稳定性方面表现出不同的机制，而果胶的有效电荷强烈依赖于其 DE 和连续相的 pH 值。果胶和乳铁蛋白在该体系中的作用机制对低分子量果胶来说是 pH 依赖性的，但对高分子量果胶如 GJLP 则不是。结果表明，在界面处形成的果胶和乳铁蛋白复合物不足以维持乳液的稳定性。本研究还表明，连续相中未被吸收的果胶分子在提供乳液的物理稳定性方面的重要性。这些分子在油滴周围形成了厚厚的多层。此外，加入 0.2%w/w 的 GJLP 可以产生稳定的乳液，这表明 GJLP 有潜力用于改善乳铁蛋白稳定的水包油乳液的稳定性。
