Construction And Stability With Soyasaponin/Soybean Protein In W/O/W Multiple Emulsion

Water-in-oil-in-water(W/O/W)type multiple emulsion(double emulsion)could transport hydrophilic and hydrophobic components simultaneously,with a"two-chamber three-phase"structure,which had great applications potential in food,medicine,cosmetics and other fields.Soyasaponin and soybean protein were two main by-products of soybean oil processing in soybean,which were abundant in degreased soybeal.The objective of this study was to formulate relatively stable W/O/W emulsion via a two-step emulsification method containing soyasaponin(Ssa)and soybean protein as raw materials.In this research,the effects of different phase volume ratio,the concentration of Ssa and soybean protein concentration on the droplet stability of the W/O and W/O/W emulsions were investigated.Main conclusions were as follows:1)W/O emulsion was constructed using Polyglycerol polyricinoleate(PGPR)and Ssa as emulsifiers and corn oil as oil phase.The results showed that there were significant differences in the stability of W/O emulsion prepared with different oil/water fractions.In particular,the ratio of the water phase to the oil phase was 30/70,which the W/O emulsion prepared had better stability.Increasing the concentration of Ssa and PGPR could be beneficial to the stability of W/O emulsion.PGPR could produce synergistic effect through hydrophobic interaction with a certain concentration of Ssa,and Ssa could be substituted for the part of PGPR in the oil phase.In the meantime,with the concentration of Ssa was 1%(w/w),the W/O emulsion prepared had smaller particle size,higher viscosity and better stability.2)W/O/W emulsion was prepared by dissolving Ssa in internal water phase,corn oil in oil phase and soybean protein isolate(SPI)in external water phase.Results revealed that the increase of Ssa concentration was not conducive to the stability of emulsion.The delamination rate of emulsion with 1%(w/w)Ssa concentration was the lowest and the structure of W/O/W type droplets was the most.The volume ratio of the second phase acted more significantly effect in the stability of the emulsion.Furthermore,an E₁:W₂ ratio of 50/50 was a suitable operation parameter for the preparation of W/O/W emulsions,because the delamination rate and TSI value of emulsion were the lowest.Increasing SPI concentration could be contribute to the stability of emulsion.When SPI concentration was 3%(w/w),the emulsion delamination rate was the lowest and the stability was the best.The results of differential scanning calorimetry indicated that the water part of the above W/O/W type emulsion migrated from the internal water phase to the external water phase,which might be one of the main reasons for the gradual instability of the emulsion.3)The effects of SPI,glycinin(11S),and?-conglycinin(7S)on W/O/W emulsion were evaluated.The results showed that the stability of SPI prepared emulsion was better than 11S and7S at the same protein concentration(1%w/w).The results of interfacial tension indicated that the hydrophobic interaction occurred between the protein and PGPR,and the protein structure and molecular weight could affect its value.