辛烯基琥珀酸淀粉酯分子结构差异对其Pickering乳液释放性能的作用机制

Mechanism of Octenyl Succinic Anhydride-esterified Starches with Different Molecular Structures in Regulating Releasing Property of Pickering Emulsion

为提高功能因子的生物利用度,探讨不同分子结构的淀粉基载体材料对Pickering乳液性能的影响,该文以普通玉米淀粉和蜡质玉米淀粉为原料,通过辛烯基琥珀酸酐改性(octenyl succinic anhydride,OSA)以及高温降解(high-temperature degradation,HD),获得两种分子结构有差异的淀粉基材料,通过傅里叶红外变换光谱和X-射线衍射分析对淀粉分子结构进行表征,并测定淀粉基Pickering乳液的粒径、电位与游离脂肪酸释放情况。结果表明,在改性过程中,辛烯基琥珀酸基团成功接入淀粉分子结构中,辛烯基琥珀酸淀粉酯呈A型结晶结构,高温降解可使其黏度明显下降,便于形成稳定淀粉基Pickering乳液。此外,随着取代度的增加,Pickering乳液的粒径减小、表面负电性增加,而且在体外模拟消化过程中,淀粉基Pickering乳液的游离脂肪酸释放率随着取代度的增加从42.86%增加至47.14%,其中,淀粉OSA-Waxy-HD所制备的Pickering乳液游离脂肪酸释放速度适中,有利于功能因子的控释。

To enhance the bioavailability of bioactive ingredients,this study investigated the relationship between starch-based carrier materials with different molecular structures and the properties of Pickering emulsion. Common maize starch and waxy maize starch were modified by octenyl succinic anhydride(OSA)esterification and high-temperature degradation(HD). The obtained two modified starches were characterized by Fourier transform infrared spectroscopy and X-ray diffraction and then used for the preparation of Pickering emulsions. The particle size,zeta-potential,and of free fatty acid(FFA)release rate of the Pickering emulsions were determined. The OSA-starch with the OSA group showed A-type crystalline structure. The high-temperature degradation significantly decreased the viscosity of starch,which was beneficial to the formation of stable starch-based Pickering emulsion. Moreover,as the degree of substitution(DS)increased,the starchbased Pickering emulsion showcased decreased size and increased zeta-potential. In in vitro digestion,the FFA release rate of the Pickering emulsion increased from 42.86% to 47.14% with the increase in DS. The OSA-Waxy-HD Pickering emulsion with steady FFA release rate had good performance in controlled releasing.