Preparation,Properties And Application Of Octenyl Succinic Anhydride Modified Yam Starch

In this study,yam starch was isolated from the tuber of Dioscorea oppsite Thunb by alkali immersion.The optimum conditions of octenyl succinic(OS)yam starch were determined by single factors and orthogonal experiments.The OS starch with the degree of substitution(DS)was 0.0162 and the reaction efficiency(RE)was 69.8%.Yam starch(Y),normal corn starch(N),waxy corn starch(W)and potato starch(P)were used to take esterification reaction,respectively.The DS were investigated by the titration method.The physicochemical properties were characterized by Laser particle size analyzer,scanning electron microscopy(SEM),polarizing microscopy,X-ray diffraction(XRD),fourier transform infrared spectroscopy(FT-IR),differential scanning calorimetry(DSC)and rapid viscosity analyzer(RVA).The results showed that the physicochemical properties of different starch led to esterification reaction product properties different.The OS starches with the DS were W,N,Y and P in turn.The particle size was opposite to the specific surface area.When specific surface area was larger,DS would be larger.All starch samples showed the typical maltese cross pattern,but the crystal type was different.In addition,esterification did not affect the crystallinity.The functional groups of the four kinds of starches were identical basically,and the group of OS had been introduced to starch ester.The order of the gelatinization temperature of the starches was Y>W>N>P,and esterified starches were lower than native starches.The yam starch was heated in ethanol solution at different temperatures to cause a certain degree of amorphization,and then esterified with octenyl succinic anhydride(OSA).Amorphization starches exhibited higher size,lower polarized cross and crystallinity,higher pasting temperature,lower enthalpy change,higher viscosity and the stability.Results showed that no significant difference was observed in particle shape and crystalline structure of esterified starches.The esterification reaction increased the particle size,reduced the gelatinization temperature,decreased the enthalpy change,and increased the viscosity and stability.The yam starch ester(YE),normal corn starch ester(NE),waxy corn starch ester(WE),potato starch ester(PE)and amorphized yam starch ester were used as emulsion stabilizer in the soybean oil emulsion system.Results showed that the order of emulsifying activity(EA)was amorphized starch ester,WE,NE,YE,PE and emulsion stability(ES)was amorphized starch ester,YE,WE,NE,PE.