关键词: 玉米淀粉, 糊化, 冷冻干燥, 滚筒干燥

Abstract:

In this paper, the physicochemical properties of gelatinized corn starch after vacuum freeze-drying were investigated by means of SEM, Brabender viscosity test and XRD. Then, the results were compared with those of native starch and of the pregelatinized starch after drum drying. It is found that （ 1 ） the majority of the freeze-dried gelatinized starch is loose and porous while the minority is fragmentary; （2） the trend in Brabender viscosity curve of the freeze-dried gelatinized corn starch is similar to that of native starch but is distinctly different from that of the pregelatinized starch ; （3） the XRD spectrum of the freeze-dried gelatinized corn starch is similar to that of the pregelatinized starch in terms of dispersion peak pattern, but its peak intensity is weaker; （4） the freeze-dried gelatinized corn starch is of the largest granular diameter （ i. e. , 110. 468 um） but of weak solubility in cold water and of relatively low transparency which is just a little higher than that of native starch; and （5） the freeze-dried gelatinized starch is characterized by a shear thinning behavior with low apparent viscosity and high thawing stability.

Key words: corn starch, gelatinization, freeze-drying, drum drying