一步法制备大豆不溶性肽-壳聚糖复合颗粒稳定的Pickering双重乳液及其表征

One-step Fabrication and Characterization of Pickering Double Emulsions Stabilized by Soybean Water-insoluble Peptide-chitosan Composite Particles

该研究探讨了大豆分离蛋白(SPI)酶解产生的水不溶性肽聚集体(SWIP)经过超声处理后与壳聚糖(CS)进行复合,所制备的复合胶体颗粒(SWIP-CS)作为乳化剂通过简单的一步均质法制备得到W/O/W型Pickering双重乳液,进一步研究了不同壳聚糖浓度与pH值对乳液外观、粒径、微观结构及流变特性的影响。结果表明,大豆水不溶性肽聚集体与壳聚糖之间通过氢键相互作用。在pH为3.0、3.8、4.0和5.0时,壳聚糖浓度为0.125%、0.25%和0.5%及油相分数50%时均能够制备稳定的Pickering双重乳液。壳聚糖浓度的增加使得乳液的粒径有着显著性的降低(30.6~23.9μm),且较高浓度(0.5%)时能够改善双重乳液的稳定性与凝胶特性。而随着pH从3.0增加到5.0,双重乳液液滴内部的小液滴数量逐渐减少,其稳定性与凝胶特性也在相应的降低。本研究为制备双重乳液提供了一种简便有效的策略,对于食品工业、化妆品与医药领域上的应用具有重要意义。

Enzymatic hydrolysis of soy protein isolate(SPI)afforded water-insoluble peptide aggregates(SWIP),which were sonicated and further compounded with chitosan(CS)to prepare composite colloidal particles(SWIP-CS).These particles were used as emulsifiers to obtain W/O/W Pickering double emulsions in a simple one-step preparation process.The effects of different chitosan concentrations and pH levels on the appearance,particle size,microstructure,and rheological properties of the emulsions were also investigated.Mechanistic studies revealed that the water-insoluble aggregates interacted with chitosan by hydrogen bonding.Stable Pickering double emulsions were prepared using chitosan at concentrations of 0.125%,0.25%,and 0.5%and an oil phase fraction of 50%at pH 3.0,3.8,4.0,and 5.0.The increase in chitosan concentration resulted in a significant decrease in the particle size of the emulsions(from 30.6 to 23.9μm),and the stability and gel properties of the double emulsions were improved at a relatively high chitosan concentration(0.5%).However,as the pH was increased from 3.0 to 5.0,the number of small droplets inside the double emulsion droplets gradually decreased,which in turn reduced the stability and gel properties of the droplets.Thus,this study provides a simple and effective strategy for the preparation of double emulsions,which can be applied to food,cosmetics,and pharmaceutical industries.