Preparation, Properties And Application Of Crosslinked And Esterified Porous Rice Starch

This study was designed to synthetize the crosslinked and esterified porous rice starch(CEPRS) by crosslinking of phosphorus oxychloride, hydrolysis of complex enzyme and esterification of octenyl syccinic anhydride (OSA) successively. And the absorption abilities and structural properties of the crosslinked and esterified porous rice starch were investigated as well as its application on absorption.The criterion, evaluating the absorption abilities of starch, was established. The result showed that the relativities of the amount of methylene blue absorption with the open-hole degree of porous rice starch (PRS) and the substitution degree of esterified porous rice starch (EPRS) is best. Therefore, the amount of methylene blue absorption was chosen as the criterion for evaluating the absorption abilities of starches.The optimum technological process, producing CEPRS, was analysed in the study. It was revealed that the crosslinking condition were crosslinker 0.6%, reaction time 90 min, reaction pH 11, and temperature of 35℃. The enzymolysis condition were enzyme dosage 55%, reaction time 12 h, hydrolysis pH 3.6, temperature of 35℃.The esterification condition of CPRS were temperature of 35℃, ph 8.5, reaction time 2h.In addition, the absorption abilities of PS, crosslinked pours rice starch (CPRS) and CEPRS were also investigated. It is revealed that CEPRS has the strongest absorption, and its amount of methylene blue absorption was 3.69 mg/g. Followed by the CPRS and PS. The result of absorption order kinetics of the there products showed that CEPRS had the fastest speed during the methylene blue absorption progress. Infrared spectrum indicated OSA have been embed into the CEPRS, and the P-O-C characteristic peak were found in spectrum. X-ray diffraction patterns showed that the crystal structure of starch was not changed after modification, which illustrated that the reactions were happened in the amorphous region. Via the investigation from SEM, the surface of starch became rough and irregular with more holes existed on the surface.Finally, the application of CEPRS on the absorption of capsanthin was analyed, and its absorption progress was research by three dynamics, including the first absorption kinetics model, the second absorption kinetics model and dynamic model of the diffusion. The result showed that the second absorption kinetics model has the best relativities with the experiment results. Effects of temperature and light on capsanthin powder were also researched. It is revealed that capsanthin powder had better temperature and light resistance than capsanthin.