采用醇水相湿热处理对玉米淀粉进行研究，考察了处理温度范围为70~90 ℃内淀粉颗粒偏光十字，形貌，粒径分布，结晶结构及糊性质等性质变化。随着湿热处理温度升高，发现：淀粉颗粒偏光十字消失增多，最终颗粒破碎；颗粒平均粒径由23.6 μm持续增加至50.4 μm，其中小颗粒（<10 μm）数目减少，中等颗粒（10~30 μm）和大颗粒（30~100 μm）数目均有不同程度的增加；淀粉颗粒表面出现小孔和凹坑，最终颗粒成团，干燥粉碎之后破碎成片状；淀粉的X射线衍射在衍射角15°，18°和23°处峰强度逐渐降低，但在衍射角20°处峰强度增加。淀粉的Brabender粘度曲线显示，湿热处理后玉米淀粉糊化起始温度由80.5 ℃升高至90.6 ℃，粘度降低，表明玉米淀粉热糊稳定性和冷糊稳定性增强，糊凝沉性降低；测定分析淀粉分子量可知，淀粉颗粒内部分子链发生了断裂、降解。

Nature corn starches treated by heat-moisture with water-ethanol mixtures were investigated in terms of polarization cross, morphology, size distribution, crystal structure and paste properties within the temperature range of 70~90 ℃. With the increase of the temperature in the treatment system, some phenomena were found as follows: the disappearance of the granules birefringence increased, and the granules broke in the end. The average radius of the starch granules was augmented from 23.6 μm to 50.4 μm and the amount of the small granules (<10 μm) decreased. Besides, the number of the medium granules (10~30 μm) and large granules (30~100 μm) increased in different degrees. Small holes and pits were observed on the surface of the granule, and the granules conglobated at high temperature in the end .After drying and grinding, the granules broke into flakes. X-ray diffraction intensity gradually reduced at the diffraction angle of 15°, 18° and 23°, but strengthened at 20°. Starting temperature of corn starch gelatinization raised from 80.5 ℃ to 90.6 ℃, and viscosity of the starch decreased, which indicated that the stability of both warm and cold paste improved while the retrogradation of the starch reduced. Determination of molecular weight of the starches displayed that molecular chains were ruptured and degraded during the heat-moisture treatment.

国家自然科学基金-广东联合基金项目（U1201242），广东省科技计划项目（2009A080209002、2010A080403005)，国家科技支撑计划课题（2009BAI84B06、2011BAE15B02）