Research On Construction And Application Of Pickering Emulsion Stabilized By Quinoa Starch/Chitosan Complex

In this thesis,by used quinoa starch and chitosan to synthesize a pH-responsive composite particle with different grafting rates.Then used this particle to construct a responsive Pickering emulsion,and explored the application of responsive Pickering emulsion to the controlled release of functional active substances.After extrusion,the particle size of quinoa starch becomee smaller,and the reactive sites with octenyl succinic anhydride increase.The cross-linking reaction had the best reaction effect at a temperature of 30?,a reaction time of 20 minutes,and an addition amount of glutaraldehyde of 3%..The grafting rates of OS-EQSC-1 to OS-EQSC-5 were 2.56%,6.30%,7.36%,9.17%,and 11.85%,respectively.The responsive particles were characterized by FTIR,~1H NMR,XRD,RVA,DSC,and SEM.The research results found that the OS group and chitosan were successfully introduced into the molecular chain of quinoa starch,and the starch crystal structure was destroyed after the reaction.Crystallinity decreased,peak starch viscosity decreased,disintegration value decreased,retrogradation value increased,starch gelatinization was suppressed.It was observed by SEM that the surface of the responsive particles formed by cross-linking became rough,and a flaky structure appeared.The contact angle and surface tension indicated that grafted chitosan can significantly improve emulsification,OS-EQSC has a larger contact angle and lower surface tension.Among them,the contact angle of OS-EQSC-2 is the largest,and the surface tension value is the lowest.OS-EQSC stabilized Pickering emulsion with responsive particles.The most stable condition of Pickering emulsion was that the oil phase was selected from sunflower oil,the oil phase volume fraction was 0.4,and the particle concentration was 1.5 wt%.The addition of certain sodium chloride can play a synergy role of the emulsion.Confocal laser observation clearly observed that OS-EQSC adsorbed to the oil-water interface,which can stabilize the emulsion well.The spherical shape was observed in the scanning electron microscope image,indicated that the OS-EQSC had sufficient flexibility to bend along the surface,further indicated that OS-EQSC had good emulsifying properties.Among them,the emulsion stabilized by OS-EQSC-2had the highest stability at pH 6.0.After resveratrol was embedded,the particle size and potential of Pickering emulsion did not change significantly,indicated that the composition and structure of the emulsion interface determined the particle and charge size of the emulsion.Compared with OS-EQS,responsive particles OS-EQSC had a better embedding effect on resveratrol.The OS-EQSC-stabilized Pickering emulsion can protect and embed functional active substances(resveratrol),controlled release,while the emulsion has a higher DPPH clearance rate,of which OS-EQSC-2 has the best effect.