Fabrication Of Starch-lipid Complex Nanoparticles And Its Application In Pickering Emulsion

In this study,the V-type crystalline starch was prepared by the anti-solvent.Physical and chemical properties of the original starch and its corresponding V-type crystalline starch were explored.V-type crystalline starch and lauric acid were complexed by a solid encapsulation method.To further explore the emulsification properties of starch-fatty acid complex(SFAC),different amylose content and complexing temperature were set.The optimal conditions for SFAC stabilized emulsion were explored by setting different starch-lipid complex concentration and oil phase volume fractions of emulsion.The study provides theoretical basis for the application of starch-lipid complexes in the food and chemical fields.Five kinds of corn starch(WMS,NMS,HA5,HA7,HA8)were chosen as raw materials,V-type starch was prepared by anti-solvent,the physical and chemical properties of original starch and V-type starch were first compared by XRD,DSC,NMR,SEM and particle size measurement.Complex index(CI)of SFAC was measured and the results showed that complexing index of SFAC prepared by solid encapsulation method increased as amylose content increased.CI of the SFAC was basically same after washed by ethanol,indicating there was unstable structure existed in SFAC.The contact angle of SFAC was enhanced compared with V-type starch and showed better emulsifying properties and its emulsion exhibits stronger storage stability.Normal maize starch(NMS)was chosen as raw material for moderate amylose content.The structural characteristics and emulsifying properties of the starch-fatty acid complex(SFAC)were explored as a function of the complexing temperature.X-ray diffraction and differential scanning calorimetry confirmed that SFAC was mainly composed of type-I amylose inclusion complexes.Contact angle measurements revealed that the hydrophobic properties of SFAC were closely related to the temperature-regulated complex index.The particle size range of SFAC gradually increased(200 nm-1700 nm)as the complexing temperature increased,which is caused by aggregating particles at high temperatures.CI of SFAC first rises and then decreases as temperature raised and showed highest CI of 61.7% at 70 ℃.The change trend of the contact angle of SFAC was consistent with the change of CI which was largest at 70 ℃ of 130.9°,indicating the amount of SFAC determined the degree of hydrophobic modification.The physical and chemical properties of the emulsion were closely related to hydrophobicity,and appropriate hydrophobicity is necessary for a stable emulsion.The particle size of SFAC stabilized emulsion was small(10μm the lowest).The particle size of emulsion did not show great change much after storage,indicating its strong stability.SFAC emulsion could converted into emulsion gel under the condition of adding more than 2% and medium oil phase volume fraction(40-60%).Confocal laser microscope(CLSM)results verified that SFAC stabilized emulsion was Pickering emulsion.The formation and stability of emulsion gel was attributed to three-dimensional network structure,which provides a theoretical basis for its multi-directional application.