Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona, Martí i Franquès, s/n, 08028 Barcelona, Spain.
Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona, Martí i Franquès, s/n, 08028 Barcelona, Spain.
Food Res Int. 2022 Dec;162(Pt A):111945. doi: 10.1016/j.foodres.2022.111945. Epub 2022 Sep 17.
Arbequina monovarietal extra virgin olive oil (EVOO) was fractionated through a multi-step dry fractionation method. Three of the isolated fractions were selected and analyzed: one being liquid at 4 °C, and two being solid at 4 °C, and at 12 °C. Differential scanning calorimetry (DSC) combined with synchrotron radiation X-ray diffraction (SR-XRD) techniques were employed to monitor the polymorphic crystallization and transformation processes when samples were cooled from the melt to complete crystallization and reheated at a rate of 2 °C/min. Fatty acid profiles and α-tocopherol contents were also determined for EVOO and associated fractions. Each sample exhibited a different and unique crystallization and polymorphic behavior, and the number of crystallizing forms and complexity of transitions increased for solid fractions. In more detail, just two polymorphs (β'-2L and β'-2L) were detected in the liquid fraction, whereas the fraction which remained in the solid state at 12 °C exhibited six different phases (α-2L; β'-2L; β'-2L; β'-2L; β'-3L; β'-3L). These dissimilarities were strongly correlated with meaningful variations in the fatty acid moieties forming TAG structures and caused large deviations in the crystallization and melting temperatures. As an example, melting temperatures of the liquid and the solid fraction at 12 °C were about -3 °C and 17 °C, respectively. It may be worth exploring the potential of EVOO fractions to be used for improving properties of food stuff, among others. The liquid fraction may be of interest due to its high nutritional value owing to elevated contents in monounsaturated fats and antioxidants, whereas the solid fraction at 12 °C may become a good choice to be used as a high-oleic soft fat.
阿贝基纳单一品种特级初榨橄榄油（EVOO）通过多步干法分馏进行分离。选择并分析了三个分离得到的部分：一个在 4°C 下为液态，两个在 4°C 和 12°C 下为固态。采用差示扫描量热法（DSC）结合同步辐射 X 射线衍射（SR-XRD）技术，监测样品从熔融态冷却至完全结晶以及以 2°C/min 的速率再升温过程中的多晶型结晶和转变过程。还测定了 EVOO 和相关部分的脂肪酸谱和 α-生育酚含量。每个样品都表现出不同且独特的结晶和多晶型行为，固态部分结晶形式的数量和转变的复杂性增加。更详细地说，仅在液态部分检测到两种晶型（β'-2L 和 β'-2L），而在 12°C 下仍处于固态的部分则表现出六种不同的相（α-2L；β'-2L；β'-2L；β'-2L；β'-3L；β'-3L）。这些差异与形成 TAG 结构的脂肪酸部分的显著变化密切相关，并导致结晶和熔融温度的大幅偏差。例如，液态和 12°C 下的固态部分的熔融温度分别约为-3°C 和 17°C。探索 EVOO 部分用于改善食品等其他物质的特性的潜力可能是值得的。由于其单不饱和脂肪和抗氧化剂含量较高，液态部分可能因其高营养价值而受到关注，而 12°C 下的固态部分可能成为用作高油酸软脂的良好选择。
