High amylose corn starch as raw material, through the heat treatment preparation of pregelatinized starch, and citric acid were esterified. Using in vitro model, Fourier transform infrared spectrometer(FTIR), scanning electron microscopy(SEM) and thermogravimetric analysis(TG) of two straight chain starch proper-ties high difference method. The results showed that compared with the raw starch, pregelatinized starch more significantly improve the degree of esterification and reduced its digestibility. Comparison of two kinds of esteri-fied starch, citric acid esterification pregelatinized starch will lead than raw starch citric acid esterification were lower the rate of digestion, the low digestibility was associated with high degree of substitution, its relevance was verified by absorption characteristics of Fourier transform infrared spectroscopy. At the same time, TG anal-ysis showed that citric acid esterification of pregelatinized starch and its thermal decomposition at high tempera-ture, Thermal stability was stronger. These structural characteristics may be related to its low digestibility. The further study of this study had a certain guiding significance for the further improvement of resistant starch con-tent in starch.%以高直链玉米淀粉为原料,通过湿热处理制备预糊化淀粉,然后分别进行柠檬酸酯化处理.利用体外消化模型、傅立叶变换红外光谱仪(Fourier transform infrared spectroscopy,FTIR)、扫描电镜(Scanning electron microscopy,SEM)和热重分析(Thermogravimetric differential thermal analyzer,TG)等方法研究两种高直链淀粉性质的差异.结果表明,与原淀粉相比,预糊化处理更显著提高淀粉的酯化程度并相应地降低其消化率.两种酯化淀粉性质比较发现,预糊化淀粉的柠檬酸酯化会导致比原淀粉的柠檬酸酯化样品更低的消化率,这种低消化率的发生与其高取代度有关,其关联性通过傅立叶变换红外光谱的特征吸收验证.同时,TG分析表明,柠檬酸酯化的预糊化淀粉其热分解温度更高,热稳定性更强.这些结构特征均可能与其低消化率有关.本研究的深入对于进一步提高淀粉中的抗性淀粉含量具有一定的指导意义.
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