Study On The Effect Of PH?Na~+ And Extractant On Emulsifying Properties Of Soy Hull Polysaccharide

Soy hull polysaccharide has the abilities of thickening and gelatinization.At present,the study of soy hull polysaccharide was confined to extraction,isolation and primary physicochemical analysis,lacking of emulsifying properties analysis,which limited soy hull polysaccharide utilzation in pharmaceutical and food industry,etc.In this paper,two kinds of Soy hull polysaccharides were extracted with ammonium oxalate and sodium citrate to characterize their chemical properties and conformation,Focus study on the effects of concentration and environmental factors(pH and ionic strength)on the stability of SHPA and SHPS emulsions.The adsorption characteristics at the oilwater interface were characterized by means of cryo-scanning electron microscopy and dynamic drop analysis.The main conclusions were as follows:1.The chemical properties and conformation of the two kinds of polysaccharides were different.The polysaccharide content,protein content and molecular weight of SHPS were higher than SHPA;The monosaccharide type was mainly composed of arabinose,galactose,mannose and galacturonic acid;The SHPS molecule exhibited a spheroid body with a smooth surface.The SHPA molecule was chain-like with a rough surface and wrinkles.2.Emulsifying activity and interface adsorption capacity of SHPS are better than SHPA without adjusting the pH value of the system.SHPS prevents the droplets from coalescence by steric hindrance and electrostatic repulsion.The SHPS emulsion interface film was strong,the particle size was smallest,the distribution was uniform,the viscosity was moderate,at the concentration of 0.9%,and it can be stored for more than 30 d.While SHPA existed in the long chain intertwined at the interface,the network structure formed was not dense,and the SHPA emulsion was unstable.3.When the pH value of the emulsion system was 3.0 and the salt ion concentration was 0.1 mol/L,the emulsifying activity,interfacial adsorption capacity and steric hindrance of SHPA were significantly enhanced.The emulsion was the most stable.When the salt ion concentration exceeded 0.1 mol/L,the emulsion occurred flocculation.For SHPS,the SHPS emulsion was completely flocculated regardless of the presence of salt ions.When the pH value of the emulsion system was 5.0,the network structure of SHPA was weak,which led to the accumulation of oil droplets.The stability of the emulsion was worse after the addition of salt ions.The SHPS emulsion without adding salt ions had good stability,the salt ion concentration reached 0.2 mol/L,and the emulsion appeared to flocculate.In conclusion,SHPS exhibited excellent emulsifying activity and stability,while SHPA can be used as an effective emulsifier in acidic O/W emulsions.Study about the emulsifications of SHP and other fractions,in order to provide experimental support and theoretical support for the development of a new natural plant polysaccharide emulsifier.