油炸对马铃薯淀粉特性的影响

本文采用直接油炸淀粉的方法,研究不同油炸温度对马铃薯淀粉结构和性能的影响。采用电子扫描显微镜(SEM)、偏光显微镜、X-射线衍射仪(XRD)、Brabender 粘度仪等对油炸处理后淀粉的颗粒形态、结晶结构、糊化性质、透明度及冻融稳定性等进行测定分析。结果表明,随着油炸温度的升高,马铃薯淀粉的颗粒表面结构发生了明显的变化,淀粉颗粒表面出现凹陷、膨胀和破裂,样品的偏光十字双折射强度减弱,甚至消失;油炸破坏了淀粉的结晶结构,180℃油炸淀粉结构变化最显著,最适于淀粉的消化吸收;随着油炸温度的升高,样品粘度逐渐降低,且峰值粘度小于原淀粉;油炸淀粉的透光率较低,冻融稳定性较差,且均低于原淀粉,油炸淀粉类食品不适于冷冻。

Effect of high temperature frying on the structure and properties of potato starch

In this paper, the physicochemical properties of potato starch fried at different temperatures were investigated. Changes of the morphological characteristics of starch granules, crystal structure, pasting properties, the transparency and freeze-thaw stability of starch were monitored by using SEM, polarizing microscope, XRD and Brabender Viscograph. The results showed that the morphological characteristics of starch granules changed significantly. As the frying temperature increased, some granules appeared to be sunken, expanded and ruptured. The polarized crosses of the frying starch became more blurred, and eventually disappeared. The crystal structure of starch was destroyed, changes of the structure of the frying starch at 180℃ was the most significantly, which explained that the sample was the most suitable for the digestion and absorption. The viscosity of the samples gradually decreased with the frying temperature increasing. Compared with the native starch, the peak viscosity of samples decreased. The transparency and freeze-thaw stability of the frying starch were lower than that of native starch, fried starchy food was not suitable for freezing.