基于环糊精的食品级Pickering乳液构建

Fabrication of Food-grade Pickering Emulsions Stabilized by Cyclodextrins

考察环糊精(cyclodextrins,CD)结构、CD质量浓度、油相类型、油水比等因素对O/W型Pickering乳液形成的影响,系统比较了α-、β-及γ-CD稳定的中链脂肪酸甘油三酯(medium-chain triglyceride,MCT)基Pickering乳液的微观结构、微流变性质及稳定性,结合分子对接方法,模拟CD/MCT包合物的形成,揭示造成CD乳化能力差异的原因。结果表明α-CD和β-CD有较好的乳化稳定性,其乳化稳定性随油水比和CD质量浓度的增加而增强,油相类型对乳化稳定性也有显著影响。α-CD和β-CD均能显著降低油/水界面张力,且效果接近。α-CD与MCT分子间结合作用强,易于形成两亲性超分子,因而其在低质量浓度(5 mg/mL)时乳化稳定性优于β-CD。β-CD在油水界面的驻留性虽略逊于α-CD,但在高质量浓度(15、25 mg/mL)时其不仅可在油/水界面发挥乳化作用,还可通过水相中的沉淀聚集,阻碍油滴间的碰撞和凝聚,表现出更好的乳化稳定性。本研究对于研发新型食品级Pickering乳液产品,推动CD在食品领域的应用具有一定的参考意义。

In this study, the effects of cyclodextrin (CD) structure, the amount of CD added, oil phase type and oil-toaqueousphase ratio on the formation of oil-in-water (O/W) Pickering emulsions were investigated. The microstructures,microrheological properties and stabilities of medium-chain triglyceride (MCT)-based Pickering emulsions stabilized by α-, β-and γ-CD were systemically compared. In order to clarify the difference among CDs in emulsifying capacity, we simulatedthe formation of CD/MCT inclusion complexes using molecular docking. We found that both α- and β-CD exhibited goodemulsion stability, which could be further enhanced with increasing the oil-to-water ratio and the amount of CD added andcould also be obviously affected by oil phase type. Both α- and β-CD could reduce the O/W interfacial tension with similareffects. Thanks to its stronger interaction with MCT, α-CD could more easily form an amphiphilic supramolecule with MCT,thereby exhibiting higher emulsion stability than β-CD at a low addition amount (5 mg/mL). Although β-CD had slightlylower adsorption capacity at the O/W interface than α-CD, it could not only act as an emulsifier at the interface but alsoprevent the collision and coalescence of oil droplets through its participation in aggregation in the aqueous phase, whichcontributed to its stronger performance at high addition amounts (15 and 25 mg/mL). The obtained results are of referencesignificance to develop new food-grade Pickering emulsions and promote the application of CDs in foods.