Emulsifying Properties And Related Molecular Mechanism Of Soy Glycinin Regulated By Covalent Cross-linking With Soy Soluble Polysaccharide

With the increasing emphasis on health and nutrition,emulsions stabilized by plant storage globulins have broad application prospects in food,medicine and other fields.However,plant storage globulins have poor emulsifying properties compared to animal proteins.Glycation with carbohydrates has been considered to be one of effective strategy to improve the emulsifying properties of plant storage globulins.Soy glycinin(SG),as a plant storage globulin with wide source,high nutritional value and good hydrophilic property,has not been reported yet to be further improved emulsification by glycation with homologous polysaccharides.Therefore,in this paper,soy glycinin was modified by glycation with soy soluble polysaccharide(SSPS),and the molecular mechanism of the stable emulsion and the fabrication of stable high internal phase emulsion were investigated.Firstly,the SG was modified by glycation with SSPS,and the conjugates were characterized.The results indicated that the glycation occurred in both acidic(A)and basic(B)polypeptides to a similar extent.The glycation with the incresing degree of glycation(DG)led to a progressive decreased in solubility and surface hydrophobicity,but remarkably increased the magnitude of ?-potential.Dynamic latter scattering,endogenous fluorescence spectroscopy and circular dichroism results showed that the glycation increased the conformational flexibility of the 11S-form SG at the quaternary level,in a DG dependent way.Furthermore,the results of the turbidity test showed that the emulsification activity of SG by glycation with SSPS was significantly improved.Secondly,the effect of glycation with SSPS on the emulsifying properties of SG was investigated.The results showed that the glycation significantly improved the emulsification efficiency of SG,facilitated the adsorption of the proteins at the interface,and accelerated the droplet flocculation,especially for the formation of bridged flocculation.Rheology data and morphological observations together showed that at ? = 0.6,the gel-like self-supporting emulsions was constructed to be elastic-based,which improved the fat floating stability of the emulsion.The reason for these phenomena may be related to the glycation caused SG exhibited outstanding Pickering stabilization.Finally,the SG stabilized high internal phase emulsions(HIPEs)were successfully fabricated by high-speed shear homogenization “one-pot method”.The results showed that the glycation modification reduced the concentration of SG stabilized HIPEs from 0.6% w/v to 0.3% w/v,and improved the efficiency of SG to stabilize HIPEs.In addition,the gel elasticity of HIPEs stabilized by SG was enhanced,as well as its better temperature response characteristics.The reason may be attributed to the improved adsorption of glycated SG at the emulsion interface,and indicated that glycated SG is more effective as a Pickering stabilizer.In summary,glycation with SSPS can significantly improve the emulsifying properties of SG and enhance the gel network strength of SG stabilized HIPEs.And the findings would be of great importance for providing new knowledge about the molecular mechanism of oligomeric globulins by the glycation with polysaccharides,and broadening the application of emulsions stabilized by phytoglobulin in food,cosmetic,medicine and other fields.