Preparation And Characterization Of Soy Glycinin-based Pickering Particles

In recent years, the development of food-grade Pickering stabilizers has attracted increasing interest in the field of food and pharmaceutics, due to the outstanding stability against coalescence and their compatibility with food, soy globulin is one of potential Pickering emulsion stabilizers. Preparation of SG nanoparticles by heat treatment, Pickering emulsion stabilized by SG nanoparticles, the influence of loading curcumin on SG nanoparticles and Pickering emulsion system were reported in this work. The main results were as follows:Soy glycinin(SG) particles were formed by heating treatment with different protein concentrations, the properties of SG nanoparticles, resolubility of SG nanoparticle by freeze-drying, stability of Pickering emulsion stabilized by SG nanoparticles were studied. The particle properties indicating that heat treatment caused bigger particle size(90~150 nm) with more hydrophobic nature(relative to native SG).Concentration was favorable for the size of nanoparticles, increasing the concentration of SG can result in the larger nanoparticle size. Homogeneous, ultrasonic treatment can improve resolubility of SG nanoparticles prepared by freeze-drying. The results showed that all the heated SG particles exhibited good stability against coalescence under a 14 days storage period meaning their ability of Pickering-like stabilization. These results indicated that SG nanoparticles are good Pickering emulsion stabilizers.SG-curcumin complex nanoparticles were prepared by mixed curcumin(dissolved in ethanol) with SG particles(1:5,v/v).Influence of loading different amount of curcumin on SG nanoparticles, storage and oxidative stability of Pickering emulsion stabilized by complex nanoparticles were extensively evaluated, another emulsion stabilizer,Tween-20 as control. Loading curcumin had no obviously effect on the size of SG nanoparticles, but it had a great reduction effect on the surface hydrophobicity of nanoparticles, which revealed the complex nanoparticles were formed through the hydrophobic interactions. Prepared complex nanoparticles greatly enhance the solubility of curcumin in the water(maximum up to 6300 times). With an increase of loading curcumin, the size of Pickering emulsion stabilized by complex nanoparticles had a slightly increase. We can concluded from the storage experiment: curcumin-SG complex nanoparticle is a very well Pickering emulsion stabilizer.Emulsions had better oxidative stability which stabilized by complex nanoparticles(the hydroperoxide concentration only was 0.9 m M after stored for 14 days), compared with those stabilized by Tween-20. Loading curcumin had a slightly effect on improving oxidative stability of Pickering emulsions.