Study On Preparation And Characterization Of A Novel Dextrin Supermolecule System Based On Hydrophobic Bioactive Materials

Amylose has become an excellent structural unit of various functional materials due to its superior structural and physicochemical properties.The novel methods of enzyme technology and gradient ethanol precipitation were used to obtain the optimal host molecule（SD-40）to prepare spiral dextrin inclusion complexes with vitamin E or soy isoflavone.The content and inclusion rate of vitamin E prepared under the optimal conditions were 141.16mg/g and 64.92%,respectively.While the content and inclusion rate of isoflavone prepared under the optimal conditions were 112.49 mg/g and 68.38%,respectively.The SD-40/carbon nanotubes（CNTs）complex with regular helical morphology was successfully prepared.And the structural properties of SD-40/CNTs complex were characterized and confirmed with XRD,¹H NMR,FT-IR,Raman,AFM and SEM.The results of XRD comfirmed the formation of SD-40/CNTs complex with V-type crystalline structure.The results of Raman and ¹H NMR suggested that SD-40/CNTs complex was formed by the hydrophobic interaction and hydrogen bonds.SEM and AFM results showed that SD-40entwined through CNTs with helical structure and the diameter of SD-40/CNTs complex was34.01 nm.The formation,thermodynamic property and appearance of SD-40/vitamin E and SD-40/soy isoflavone complexes were investigated by FT-IR,XRD,DSC,¹³C CP/MAS NMR,SAXS,NOESY,SEM and CLSM.The formation of SD-40/vitamin E and SD-40/isoflavone complexes were confirmed by the results of FT-IR and DSC.The results of XRD and ¹³C CP/MAS NMR suggested that the crystalline structures of SD-40/vitamin E and SD-40/soy isoflavone were V6II and V6III types,respectively.Small angle X-ray scattering（SAXS）revealed that SD-40/vitamin E complexes formed a tighter and more compact crystallite than SD-40/soy isoflavone complexes.Furthermore,the connection structures of complexes were investigated by 2D NOESY NMR,indicating that part of vitamin E with an alkyl chain was encapsulated in the helix cavity of SD-40,whereas the aromatic ring B of soy isoflavone molecule was complexed by helix cavity and screw of SD.In this study,an in vitro gastrointestinal model that simulates digestive conditions in the mouth,stomach and small intestine was used to investigate the breakdown of SD-40 inclusion complex and release behavior of bioactive compounds.The results indicated that the complexes exhibited a controlled and sustained release behavior during in vitro digestion.In addition,the results of release and radical scavenging experiments showed that SD-40/vitamin E complex presented higher stability and stronger antioxidant capacity than SD-40/soy isoflavone complex.