| The preparation, properties of Hydroxypropylated waxy rice starch (HPWRS) and itsSuccinate are studied in this paper, in order to improve its physical chemistry properties andapplied area, and to get the better hydroxypropylated starch and its compound modified starchthen offord to theory for the patice.At the first, the preparation condition was studied in this chapter. Effects of thepropylene oxide concentration, reaction time, reaction temperature, starch concentration,alkali and sodium sulfate on substituent degree of the HPWRS were investigated, then,choose the propylene oxide concentration, reaction time, reaction temperature, alkali to designexperiment with the software of Design-expert7.0, then the equation of substituent degree wasgotten, substituent degree=0.027+0.014×A+0.015×B+0.021×C+0.011×D+(3.201E-003)A×B+(6.788E-003)×A×C+(2.584E-003)×A×D+0.010×B×C+(5.463E-003)×B×D+(3.787E-003)×C×D+(3.060E-003)×A2+(1.416E-003)×B2+(2.194E-003)×C2-(2.120E-003)×D2, the optimization technics of HPWRS analyzed by numericaloptimization of response surface, the temperature is 39.80℃, the reaction time is 19.98h, thepropylene oxide is 2.86mL, the sodium hydroxide is 0.10g.The second, the properties of HPWRS was studied. With the scanning of Electronmicroscope and RVA, there were some corrosive trails were found on the granule surface ofHPWRS, such as the shape of concave and drape. The beginning swelling temperature and thepeak viscosity of HPWRS were lower than its native starch when analyzed the swellingprocess of starch by RVA. The results also show that the apparent viscosity of HPWRS wasimproved with the increase of sucrose concentration, but its apparent viscosity was decreasedwhen NaCl concentration, acid-alkali concentration and rotor speed were increased. Theclarity of HPWRS was enhanced, when starch concentration, sucrose concentration and pHvalue were increased, but its clarity was decreased a little at the beginning and then increasedwith the increase of NaCl concentration, but the total has a little change. The starch whichwas hydroxypropylated also can improve the freeze-thaw stability and swelling capabilitysignificantly, but different starch have different clarity, whiteness, cold storage stability,freeze-thaw stability and reaction with the iodine. Then, the preparation and properties of Succinylated hydroxypropyl waxy rice starch(SHPWRS) was studied. The results show that the substituent degree of starch succinate wasimprove when the succinic anhydride was increased, and the peak viscosity, heat viscosity andfinal viscosity was improved, starch swell easily. With the increase of sucrose and starchconcentration, also can improve the peak viscosity, heat viscosity and final viscosity ofSHPWRS,meanwhile the beginning temperature also was increased.; but with the increase ofNaCl, lactic acid, citric acid and rotor speed, the peak viscosity, heat viscosity and finalviscosity of SHPWRS was fall, and the swelling speed was bated. The clarity of SHPWRSwas higher than HPWRS, and the higher of substituent degree of SHPWRS, the value wasbigger. With the increase of sucrose, the clarity of SHPWRS was improved, but was fall whenadd the NaCl. With the increase of citric acid and lactic acid, the clarity of SHPWRS was falla bit and then was improved rapid. The swelling capability and freeze-thaw stability andstorage stability were improved when the waxy rice hydroxypropylated starch reaction withsuccinate anhydride.
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