Preparation,Characterization And Stabilization Of Potato Starch-Naringin Composite Particles For Pickering Emulsion

Emulsion delivery system is an effective method to encapsulate,protect and deliver bioactive ingredients.Starch particles are widely used as natural stabilizer for Pickering emulsion due to their wide source,good biocompatibility and low cost.However,the application of starch in the food industry is limited because starch particles have strong hydrophilicity and poor emulsification.In this paper,PS-NAR composite particles were prepared by combining Naringin(NAR)with potato starch(PS),and their properties and emulsifying behavior were evaluated.In addition,the emulsifying mechanism of PS-NAR composite particles was speculated based on their structural characteristics.The results showed that PS-NAR composite particles could be used as stabilizer of starch-based Pickering emulsion and could expand the application of potato starch in food industry.The main work is as follows:1.Preparation and structural characterization of PS-NAR composite particles with different NAR addition ratios.PS-NAR composite particles with different polymerization degrees were prepared by adding different proportions of NAR to explore the effect of different proportions of NAR on the structural properties of potato starch.PS-NAR composite particles were characterized by X-ray diffraction,Fourier infrared spectroscopy,scanning electron microscopy,X-ray photoelectron spectroscopy,Solid NMR and molecular dynamics simulation.The experimental results showed that composite particles successfully formed by combining NAR with potato starch molecules through non-covalent interactions such as hydrogen bonding,and the presence of NAR changed the crystal properties,particle morphology,short-range order and optical properties of the original potato starch.2.Physicochemical properties of PS-NAR composite particles.The correlation between the change of physicochemical properties of potato starch and the ratio of NAR was investigated by changing the ratio of NAR addition.The successful recombination of potato starch and NAR was directly proved by color difference analysis,and the recombination ratio and addition ratio were positively correlated.Contact angle analysis showed that the hydrophobicity of PS-NAR composite particles increased significantly compared with the original potato starch and control samples,and the contact angle of PS-NAR composite particles(c=16%)was closest to 90°.By analyzing the thermal properties,swelling force,solubility,gel texture properties and digestion properties of composite particles,it was found that gelatinization process and the addition of NAR had different effects on the thermal properties,swelling force,solubility,gel texture properties and digestion properties of the samples.3.Emulsifying properties of PS-NAR composite particles and characterization of stable Pickering emulsion.The prepared PS-NAR composite particles were used to stabilize Pickering emulsion.It was found that the emulsion properties of the sample and the emulsion stability were significantly improved after complexing with NAR.The emulsifying properties of PS-NAR composite particles with 16% NAR addition ratio were the best,and the ROV value reached 0.9999.ROV value was much higher than that of raw potato starch(0.3329).Pickering emulsion stabilized with PS-NAR composite particles(c=16%)as emulsifier also showed the best stability.CI value of the emulsion was 2.01 after 30 days of storage,and the thermodynamic stability and centrifugal stability at 3 h were also higher than other samples.Through particle property analysis and molecular dynamics simulation,it was suggested that the mechanism of increasing emulsification performance may be the effect of benzene ring exposure in NAR.The elastic modulus(G’)of Pickering emulsion stabilized by PS-NAR composite particles as emulsifier was greater than its loss modulus(G "),indicating that Pickering emulsion has elastic gel structure.4.Optimization of preparation conditions of Pickering emulsion stabilized by PS-NAR composite particle.The emulsification and rheological behavior of starch-based Pickering emulsifier can be adjusted by changing the oil phase ratio and particle concentration during emulsion preparation.The optimal oil phase ratio and particle concentration of Pickering emulsion stabilized by PS-NAR particle were 10% and 4%respectively.