| Preparation of Octenyl succinic anhydride (OSA) modified starches from raw material potato starch and acid hydrolyzed potato starch in aqueous slurry system were first studied. Some properties of the OSA modified raw starches were also investigated in this thesis, including granules morphology of the starch, the viscosity, clarity, freeze-thawing stability of the starch paste, and the emulsification stability of the OSA modified raw starches. Then applications of the OSA modified starch substituted for butter in low fat or fat free ice creames were investigated in this thesis.At first, during the preparation of OSA modified potato starch, keeping the amount of OSA invariable(5% of dry basis of starch), the original concentration of starch slurry, temperature, pH range and period of reaction had great effects on the degree of substitution(DS) of the OSA modified starch. On the basis of this, by the perpendicular experiments, the optimized technology of the OSA modified starch was that: the original consistency of starch slurry35%, the reaction temperature35℃, pH range8.0, the reaction period 5h. However, the optimized technology of hydrolyzed OSA modified starch was that: the original consistency of starch slurry30%, the reaction temperature30℃, pH range8.0, the reaction period 5h.Secondly, OSA starch granules were observed by SEM, Light-micrograph. The result of test showed that: the reaction mainly occured at amorphous region and the hurt of starch granule was mostly introduced by hydrolization other than esterfication. Adopted by rotary viscosity analyzer, the viscosity of the 2.5% OSA modified starch gel (w/w) was determined at different rotate speed. The result showed: Potato OSA starch gel is shear-thinning, which should belong to Pseudoplastic Liquid. With the increase of DS, the clarity, stability and viscosity of potato OSA starch gel at a wild range. The viscosity and... |
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