不同链长直链糊精-维生素E复合物的制备及稳定性研究

Preparation and stabilityanalysis of different chain length linear dextrin and vitamin E inclusion complex

以蜡质玉米淀粉为原料,通过普鲁兰酶脱支结合乙醇梯度溶解法制备平均聚合度(degree of polymerization,DP)分别为14.53、16.20和25.25不同链长的直链糊精,采用共沉淀法与维生素E进行络合,制备直链糊精-维生素E复合物。结果显示,随着直链糊精链长增加,其对维生素E负载率由45.97μg/mg提高至62.71μg/mg,包埋率从39.07%增加至59.57%。傅里叶红外变换光谱和X-射线衍射仪证明,不同链长直链糊精与维生素E主要通过氢键形成复合物。热重和光稳定性分析证实,复合物的形成提高了维生素E耐热稳定性以及耐光稳定性,经过48 h紫外灯照射,长链直链糊精对维生素E保留率高达89.19%,而游离维生素E保留率仅为59.52%。结果表明,直链糊精链长增加,其与维生素E复合物耐热、耐光稳定性更强,对维生素E的保护效果更佳。研究为不同链长直链糊精在疏水性客体分子包埋领域的应用提供了重要理论依据。

Three fractions of linear dextrin(LD)with average degree of polymerization(DP)of 14.53,16.20,and 25.25 were obtained by hydrolyzing waxy maize starch with pullulanase and fractionating using the gradient ethanol dissolution method.Subsequently,LD-V E complexes were prepared by the co-precipitation method.The results showed that the payload capability of LD to vitamin E increased from 45.97μg/mg to 62.71μg/mg,and the inclusion rate increased from 39.07%to 59.57%with the increase of chain length.Fourier infrared transform spectrum and X-ray diffraction indicated that hydrogen bonding was the main driving force for complex formation.Thermogravimetric and photochemical stability analysis confirmed that the formation of complex improved the thermal and photostability of vitamin E.After 48 h of UV-irradiation,the retention rate of long-chain LD to vitamin E was up to 89.19%,while free vitamin E was only 59.52%.These results suggested that longer LD-V E inclusion compound showed stronger thermal stability and better protective effect on vitamin E and could guide the encapsulation of macromolecular guests by LD with different DP.