超高压对直链淀粉-正辛醇复合物结晶结构稳定性的影响

摘要

将直链淀粉-正辛醇复合物悬浮于40％乙醇溶液中,在不同压力下(100～500 MPa)处理10min,所得样品用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)以及热重分析仪(TG)进行测试分析.结果表明:常压下,V-型淀粉在40％乙醇溶液中稳定存在,结晶结构和衍射峰不变;100 MPa高压处理后,复合物的结晶度和颗粒外貌变化不显著,200 MPa及以上高压处理后,淀粉样品的结晶结构由V-型向无定型转变,随着压力的增加,颗粒表面由光滑逐渐变得粗糙,最终破碎;傅里叶红外变换图谱显示高压对各基团均无显著影响;尽管高压使V-型转变为非晶态,但对淀粉的热稳定性无显著影响.%Ultra-high pressure is a new type of non-thermal processing technology,which can make starch gelatinizated at room temperature or low temperature,the crystallization structure and thermodynamic properties changed,the pasting properties and other purposes improved.Amylose-n-Octanol complex suspensions of 40％ ethanol concentration were treated by high pressure under 100 to 500 MPa for 10 min.The afforded samples were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),infra-red spectroscopy(FT-IR) and thermal gravimetric analysis (TG).The results showed that V-type starch was stable in 40％ ethanol solution under atmospheric pressure,and the crystal structure and diffraction peaks were unchanged.The crystallinity and particle size of the complexes were not significantly changed under the pressure of 100 MPa,while the starch samples were changed from V-type to amorphous state under the pressure of 200 MPa and higher.The surface of the particles gradually became rough and starch granule was broken finally with the pressure increasing.FT-IR results showed that the pressure had no significant influence on groups of the starch.Although the V-type was transformed into amorphous state,the pressure had no significant effect on the thermal stability of starch.