Department of Food Technology, School of Food Engineering, University of Campinas, 80 Monteiro Lobato St., Campinas, SP 13083-970, Brazil.
Department of Biotechnological Processes, School of Chemical Engineering, University of Campinas, 500 Albert Einstein Ave., Campinas, SP 13083-970, Brazil.
Food Res Int. 2019 Oct;124:2-15. doi: 10.1016/j.foodres.2019.04.006. Epub 2019 Apr 4.
This study investigates and compares the thermal phase transition and crystallization characteristics of a commercial food grade free phytosterol blend (FP) with a stigmasterol analytical standard (SS), the FP behavior in a food model system after its addition to high oleic sunflower oil (HOSO). The properties of the FP:HOSO blends were studied by differential scanning calorimetry, solid content, crystal morphology, and X-ray diffraction (XRD) measurements. The Rietveld method (RM) was applied associated with the XRD measurements to support phase analysis and the study of crystallinity degree. The materials were also characterized by means of chemical composition, such as fatty acids and triacylglycerol profiles, for HOSO, and phytosterol profile, for FP. Regarding phase behavior and crystallinity properties, FP has very similar characteristics to SS. The thermal behavior of FP:HOSO blends has two characteristic peaks, one from FP and the other from HOSO. The similarity reported in the literature between the diffraction pattern of FP and pure phytosterols is a positive characteristic for FP. A high FP concentration resulted in high supersaturation and thus the formation of small crystals. The incorporation of HOSO reduced of the large agglomeration of FP crystals and the dispersion crystalline aggregates (spherulites) of FP crystals. The application of RM in FP:HOSO blends to quantify the crystalline and amorphous phases was successfully used. The application has provided the expected value for these phases, according to the same experimental mass ratio of the blends, thereby validating the applicability of this approach in this type of material.
本研究调查和比较了商业食品级游离植物甾醇混合物 (FP) 和豆甾醇分析标准品 (SS) 的热相变和结晶特性，以及 FP 在添加到高油酸葵花籽油 (HOSO) 后的食品模型系统中的行为。通过差示扫描量热法、固含量、晶体形态和 X 射线衍射 (XRD) 测量研究了 FP:HOSO 混合物的性质。应用 Rietveld 方法 (RM) 结合 XRD 测量来支持相分析和结晶度研究。还通过化学成分，如 HOSO 的脂肪酸和三酰基甘油谱以及 FP 的植物甾醇谱，对材料进行了表征。就相行为和结晶度特性而言，FP 与 SS 非常相似。FP:HOSO 混合物的热行为有两个特征峰，一个来自 FP，另一个来自 HOSO。FP 的衍射图案与纯植物甾醇在文献中报道的相似性是 FP 的一个积极特征。FP 的高浓度导致高过饱和度，从而形成小晶体。HOSO 的加入减少了 FP 晶体的大团聚和 FP 晶体的分散结晶聚集体（球晶）。RM 在 FP:HOSO 混合物中的应用成功地用于定量结晶相和非晶相。根据混合物的相同实验质量比，该应用提供了这些相的预期值，从而验证了该方法在这种类型的材料中的适用性。
