Research Unit Food and Lipids, KU Leuven Kulak, Department of Molecular and Microbial Systems Kulak, Kortrijk, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), Heverlee, Belgium.
Research Unit Food and Lipids, KU Leuven Kulak, Department of Molecular and Microbial Systems Kulak, Kortrijk, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), Heverlee, Belgium.
Food Res Int. 2017 Oct;100(Pt 1):841-849. doi: 10.1016/j.foodres.2017.08.015. Epub 2017 Aug 5.
The objective of this study was to investigate in depth the non-isothermal crystallization and melting behavior of binary blends of palm oil (PO) with a commercial, multi-component phytosterol ester (PE) mixture. DSC and time-resolved synchrotron X-ray diffraction (XRD) experiments were conducted on blends with a PE concentration from 0 to 100% at intervals of 10% for DSC and 20% for XRD. Based on XRD, two different ordered structures were identified in pure the PEs. The structure designated as PE was truly crystalline and needed a very high degree of supercooling for its nucleation from the melt. The structure designated PE formed without supercooling and showed long-range order with multiple reflections at small angles but only one broad reflection at high angle, typical of liquid crystalline samples. Furthermore, PE had a high tolerance for molecules of different chemical nature. In the PE-PO blends no other ordered structures were formed other than the ones observed in the pure PEs and PO. The peaks in the DSC runs of the PE-PO blends were linked to transitions of the different polymorphic forms. All structural information of the binary blends as a function of concentration and temperature was collected in morphology maps. The binary blends exhibited eutectic characteristics visualized in the morphology maps with a eutectic point at 40% PEs.
本研究旨在深入研究棕榈油（PO）与商业多组分植物甾醇酯（PE）混合物的二元共混物的非等温结晶和熔融行为。在 DSC 和时间分辨同步加速器 X 射线衍射（XRD）实验中，PE 浓度从 0 到 100%以 10%的间隔进行实验，对于 XRD 则以 20%的间隔进行实验。基于 XRD，在纯 PE 中鉴定出两种不同的有序结构。被指定为 PE 的结构是真正的结晶结构，需要非常高的过冷度才能从熔体中成核。被指定为 PE 的结构在没有过冷的情况下形成，并且在小角度处具有长程有序和多个反射，但在高角度处只有一个宽反射，这是典型的液晶样品的特征。此外，PE 对不同化学性质的分子具有很高的容忍度。在 PE-PO 共混物中，除了在纯 PE 和 PO 中观察到的那些之外，没有形成其他有序结构。PE-PO 共混物的 DSC 运行中的峰与不同多晶型形式的转变有关。二元共混物的所有结构信息作为浓度和温度的函数都收集在形态图谱中。二元共混物表现出共晶特征，在形态图谱中可以看到共晶点在 40%PE 处。
