本文研究了不同次数（0、1、2、3、4、5和6次）的冻融处理对糊化后的普通玉米和糯玉米淀粉凝胶理化性的影响。采用扫描电子显微镜对淀粉凝胶的微观结构进行分析，测定了凝胶化淀粉的碘蓝值、碘结合力、最大吸收波长、透明度、持水性、溶解度与膨胀力、水解特性和体外消化性。普通玉米淀粉凝胶呈孔状结构，糯玉米淀粉凝胶冻融2次后出现层状结构，二者孔径和层距都随冻融次数增加而减小。冻融循环处理对两种凝胶化玉米淀粉的碘蓝值、碘结合力、最大吸收波长和直链淀粉含量均无显著性影响。随冻融次数增加，普通玉米淀粉的透明度、持水性、RDS与SDS含量逐渐减小，而溶解度、膨胀力、水解率和RS含量逐渐升高；而糯玉米淀粉的透明度、持水性、溶解度和膨胀力逐渐减小，RDS、SDS和RS含量及水解率均无显著性变化。

Normal and waxy corn starch gels were subjected to different numbers of freeze-thaw cycles (zero, one, two, three, four, five, and six times) and the changes in their physicochemical properties were analyzed. The scanning electron microscope (SEM) was used to analyze the microstructural properties of corn gels, and iodine blue value, iodine binding force, maximum absorption wavelength, transparency, water holding capacity, solubility, swelling degree, hydrolysis characteristics, and in vitro digestibility of the gelatinized starch were also determined. The results showed that normal corn starch gels had a porous structure after gelatinization, while waxy corn starch gels had a layered structure after two freeze-thawing cycles. The pore size and layer distance decreased with increasing number of freeze-thawing cycles. Freeze-thawing had no significant effect on the iodine blue value, the iodine binding force, the maximum absorption wavelength, and the amylose content of both gelatinized corn starch samples. As the number of freeze-thawing cycles increased, there was a decrease in the transparency, water holding capacity, and content of rapidly digestible starch (RDS) and slowly digestible starch (SDS) in the gelatinized normal corn starch, while there was an increase in the solubility, swelling degree, degree of hydrolysis, and resistant starch (RS) content. The gelatinized waxy corn starch showed decreased transparency, holding capacity, solubility, and swelling degree after freeze-thawing treatment, whereas there were no significant changes in RDS, SDS, and RS content as well as degree of hydrolysis after the treatment.

基本科研创新项目（Z109021423）