氯化钾协同脉冲电场对木薯淀粉性能的影响

The Synergetic Effect of Potassium Chloride and Pulsed Electric Field Treatment on Structure and Properties of Starch with a Lower Moisture Content

试验以木薯淀粉为原料,研究脉冲电场处理以及盐离子浓度对淀粉糊化特性、热力学性质、颗粒形态以及结晶结构的影响。试验结果表明,不同浓度KCl协同脉冲处理的淀粉,其颗粒形貌也不同,脉冲电场处理过的木薯淀粉颗粒较原淀粉,其破损率增高,淀粉颗粒结构受到一定程度的破坏。随着盐离子浓度的增大,脉冲处理后淀粉颗粒表面凹陷程度越来越深,表面变得粗糙,褶皱较多。脉冲处理的淀粉的结晶结构和化学结构均未发生改变,但其相对结晶度随浓度的升高而下降,而原淀粉的短程有序结构含量最低;经小角X射线散射仪测定,随着盐离子浓度的升高,经脉冲处理后的淀粉中的散射体结构先变得疏松后又致密,淀粉半结晶层状结构厚度没有变化,但原淀粉的峰值较脉冲处理不同盐浓度的淀粉更高。脉冲处理的原淀粉较原淀粉颗粒,其结晶完整性下降;而随着KCl浓度的升高,在协同脉冲电场处理后,淀粉的结晶完整性持续下降,其结晶度也下降,当KCl浓度达到10%时,部分链段重聚形成微晶,导致焓值先降后升。

Using cassava starch as raw material,the effects of pulsed electric field treatment and salt ion concentration on starch gelatinization,thermodynamic properties,particle morphology and crystalline structure were studied.The experimental results showed that the grain morphology of starch treated with KCl of different concentrations was different.Compared with the original starch,the damage rate of cassava starch treated with pulsed electric field increased,and the structure of starch granules was damaged to some extent.With the increase of salt ion concentration,the surface depression of starch granule becomes deeper and deeper after pulse treatment.The crystal structure and chemical structure of the pulsed starch did not change,but its relative crystallinity decreased with the increase of concentration,while the content of the short range ordered structure of the original starch was the lowest.As the concentration of salt ions increased,the structure of the scatterer in the starch after pulse treatment became loose and dense,and the thickness of the semi-crystalline laminar structure did not change,but the peak value of the original starch was higher than that of the starch with different salt concentration after pulse treatment.Compared with the original starch granule,the crystalline integrity of the pulsed starch decreased.With the increase of KCl concentration,the crystalline integrity of starch continued to decline after the cooperative pulse electric field treatment,and its crystallinity also decreased.When the concentration of KCl reached 10%,some chain segments were reunited to form microcrystals,leading to the first decrease and then rise of enthalpy.