HP-β-CD对桑色素的包合作用及光稳定性研究
Preparation and stability of the inclusion complex of HP-β- CD with morin
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摘要: 以羟丙基-β-环糊精（HP-β-CD）为主体,采用冷冻干燥法制备水溶性良好的桑色素/HP-β-CD包合物。根据相溶解法研究了主客体之间的包合作用,并利用扫描电子显微镜（SEM）、粉末X射线衍射谱图（XRD）表征了包合物形成。此外,还通过差示扫描量热法（DSC）、热重分析（TG）及光稳定性分析的方法探究了包合前后桑色素光、热稳定性的变化。实验表明:桑色素与HP-β-CD形成了摩尔比1∶1的包合物,缔合常数为833（mol/L）-1。包合后桑色素的水溶性得到提升,在加入了8×10-3mol/L的HP-β-CD后,其溶解度提升了7倍。此外,经包合后的桑色素光、热稳定性也到提升,热分解温度从294℃提升至341℃,在300 min内的光稳定性也由75.2%提升至82.7%。这为桑色素作为食品添加剂在储存及使用过程中稳定性的提升提供了重要的帮助。Abstract: The water- soluble inclusion complex of morin and( 2- hydroxy) propyl-β- cyclodextrin( HP-β- CD) was prepared by freeze- drying method. The effects of the inclusion behavior of host- guest was investigated by methods of phase- solubility and characterized byscanning electron microscopy( SEM) and X- ray diffraction( XRD).Furthermore,the stability of morin and it inclusion complex was also investigated by differential scanning calorimetry( DSC),andphotostability test.The experiment showed thatmorin formed 1 ∶ 1 stoichiometric inclusion complex with HP- β- CD,and the apparent stability constant was 833( mol / L)- 1.The solubility of the morin was dramaticallyincreasedas it enhanced more than 9 times.Also the decomposition temperature of morin was improved from 294 ℃ to 341 ℃ after encapsulated by HP-β- CD and the photostability of morin was enhanced from 75.2% to82.7%.Therefore,it could be a potentially promising way to promote its stability as food additive in storage and application.
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